WO2025008611A1

WO2025008611A1 - Moulding of hollow moulded fibre products

Info

Publication number: WO2025008611A1
Application number: PCT/GB2024/051655
Authority: WO
Inventors: Daniel George PROZESKY; Theo Richard ASHCROFT; Adam Richard TURNER
Original assignee: Pulpex Limited
Priority date: 2023-07-03
Filing date: 2024-06-27
Publication date: 2025-01-09
Also published as: GB202310167D0; GB2632631A

Abstract

The present invention relates to methods and systems for moulding a hollow moulded fibre product from a fibre suspension, such as a fibre suspension comprising paper pulp. In one aspect, there is provided a method of moulding a hollow moulded fibre product from a fibre suspension. The method comprises at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity, the cavity being defined by one or more internal surfaces of the mould and the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; and subsequently introducing a fibre suspension to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.

Description

MOULDING OF HOLLOW MOULDED FIBRE PRODUCTS

TECHNICAL FIELD

The present invention relates to methods and systems for moulding a hollow moulded fibre product from a fibre suspension, such as a fibre suspension comprising paper pulp. The products may be further processed to form receptacles which may be consumer packaging, such as bottles, jars or certain types of vases, useful for holding liquids, powders, other flowable materials, one or more solid objects, or a combination thereof.

BACKGROUND

It is desirable to reduce glass and plastics use in consumable items, particularly packaging. Non-necked receptacles, such as trays, bowls and other simple shapes, as well as necked receptacles, like a bottle, jar or certain types of vase, may be made from paper pulp and other more environmentally friendly recyclable materials.

At certain stages, particularly early stages, during formation of a hollow moulded fibre product, the hollow moulded fibre product may be unevenly formed. A receptacle produced from the hollow moulded fibre product may then comprise structural weaknesses or be poorly finished.

SUMMARY

According to a first aspect of the present invention, there is provided a moulding system for moulding a hollow moulded fibre product from a fibre suspension. The moulding system comprises a mould comprising one or more internal surfaces that define a cavity, within which the hollow moulded fibre product is moulded in use, and a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; a fibre suspension supply system; a pre-filling liquid supply system; and a control system, configured to control the pre-filling liquid system and the fibre suspension supply system to: at least partially fill the cavity with a pre-filling liquid from the pre- filling supply system to form a body of the pre-filling liquid in the cavity; and subsequently introduce a fibre suspension from the fibre suspension supply system to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid. The presence of a pre-filling liquid in the cavity of the mould acts as a liquid buffer for the fibre suspension (sometimes known as a “fibre slurry”) to impact, which reduces the velocity of the fibres impacting the mould. This reduces or eliminates fibres sticking in the passageways of the mould, which in turn reduces mould cleaning requirements and reduces the fluffmess of the hollow moulded fibre product.

In some examples, the hollow moulded fibre product may be a precursor such as a bottle precursor. In some examples, the fibre suspension comprises pulp fibres suspended in water (or an aqueous liquid). In some examples, the pre-filling liquid comprises water or “white water”, which is filtered wastewater from a previous moulding operation, and which may contain a smaller number or concentration of fibres when compared with the fibre suspension.

In some examples, the body of pre-filling liquid may have been allowed to settle into a standing pool prior to introducing the fibre suspension to the cavity. In other examples, the body of pre-filling liquid may be in a dynamic or turbulent state when the fibre suspension is introduced. The shape of the body of liquid may be defined by gravity, the shape of the cavity and any hydrodynamic forces resulting from the filling of the cavity with the pre-filling liquid. In some examples, the level of turbulence present in the body of pre-filling liquid when impacted by the fibre suspension may be controlled by controlling one or more of the following: the rate of filling the cavity with the prefilling liquid; the amount of pre-filling liquid added to the cavity and/or the volume of pre-filling liquid retained within the cavity prior to introducing the fibre suspension; a delay between the at least partially filling the cavity with the pre-filling liquid and introducing the fibre suspension; any draining of the body of pre-filling liquid before or during the introduction of the fibre suspension.

Optionally, the control system is configured to: at least partially fill the cavity with the pre-filling liquid during a first time period; introduce the fibre suspension into the at least partially filled cavity during a second time period; and remove liquid from the cavity during a third time period. Time period-based control of the moulding system allows optimisation for various outcomes with respect to the hollow-moulded fibre product, such as: increase the speed of moulding and/or throughput, improve external surface finish such as smoothness, and improve the uniformity of fibre deposition.

In some examples, some of the time periods may overlap and/or may be separated by a delay. For example, liquid may start being removed from the cavity under the action of a negative pressure source (during a third time period) when the fibre suspension is being introduced into the partially filled cavity (during a second time period) but not until after pre-filling of the cavity has been completed. In another example, the first and second time periods may overlap such that the fibre suspension starts being introduced before filling of the cavity with the pre-filling liquid has been completed. In another example, the delay between completion of pre-filling the cavity (end of first time period) and beginning introducing the fibre suspension (start of third time period) may be set to allow the body of pre-filling liquid to settle into a substantially static condition.

Optionally, the second and third time periods overlap with each other and the first time period does not overlap with the third time period. This configuration prevents liquid from being drained from the cavity whilst the cavity is still being filled with pre-filling liquid. This increases the size and reduces the turbulence of the body of pre-filling liquid present which may improve smoothness and/or uniformity of fibre density properties of the hollow-moulded fibre product.

Optionally, the mould comprises an inlet into the cavity to receive the pre-filling liquid or the fibre suspension, wherein the inlet is located above the cavity. Such an arrangement allows the pre-filling liquid or the fibre suspension to flow into the cavity under the assistance of gravity, from their respective pre-filling liquid supply system or fibre suspension supply system. The inlet may be used for the introduction into the cavity of one of the pre-filling liquid, the fibre suspension, or both the pre-filing liquid and the fibre suspension. This improves flow of the pre-filling liquid and/or fibre suspension and enables them to be more easily and/or finely controlled improving the overall quality of the hollow moulded fibre product. This may also allow the omission of positive pressure being applied to force the pre-filling liquid and/or the fibre suspension into the cavity, which in turn simplifies the control system and the overall moulding system.

In some examples, separate inlets may be used for introducing the pre-filling liquid and the fibre suspension into the cavity. For example, a first inlet located above the cavity may be provided for the introduction of fibre suspension into the cavity, and a second inlet located below the cavity may be provided for the introduction of pre-filling liquid into the cavity. More than one inlet may be provided for the introduction of prefilling liquid, for example if the mould is split into mould halves which are joined in use for moulding the hollow moulded fibre product.

Optionally, the cavity has an elongate shape with the inlet located at one longitudinal end of the elongate shape. Such an arrangement may improve the effectiveness of the pre-filling liquid acting as a liquid buffer against the introduction of the fibre suspension and/or may improve the distribution of fibres in the hollow moulded fibre product. In some examples with separate inlets for introducing pre-filling liquid and fibre suspension into the cavity, the separate inlets may be located at opposite longitudinal ends of the cavity.

In some examples, the mould may be vertically or substantially vertically oriented. For example, where the hollow moulded fibre product is a bottle precursor, the mould may be oriented such that the neck of the formed bottle precursor is at the top of the mould whilst the base of the formed bottle precursor, which is facing the neck, is at the bottom of the mould. In some examples, a bleed valve is provided in a conduit between the fibre suspension supply system and/or the pre-filling liquid supply system to the cavity such that the cavity can be placed under atmospheric pressure. This encourages flow of fibre suspension and/or pre-filling liquid from the fibre suspension supply system and/or the pre-filling liquid supply system, respectively, towards the cavity, with or without the application of a positive pressure to the fibre suspension and/or the pre-filling liquid. In some examples, one or more pumps may be employed to force the pre-filling liquid and/or the fibre suspension into the cavity.

Optionally, a major axis of the elongate shape of the cavity is vertically oriented. Optionally, the moulding system comprises a negative pressure source, and the control system is configured to control the negative pressure source to apply a negative pressure to the exterior of the mould when controlling the fibre suspension system to introduce the fibre suspension to the at least partially filled cavity. The use of negative pressure applied to the exterior of the mould accelerates removal of liquid from the cavity of the mould which may result in a faster moulding process, improved distribution of fibres and/or improved external surface finish of the hollow moulded fibre product.

Optionally, the control system is configured to control the amount of fibre suspension introduced into the partially filled cavity using a flow rate of the fibre suspension into the partially filed cavity. The use of the flow rate of the fibre suspension into the partially filled cavity simplifies the dosing of fibre suspension required to mould the hollow moulded fibre product. Dosing may otherwise be difficult in the presence of the pre-filling liquid which adds mass to the mould that may confuse other dosing methods such as weighing.

In some examples, a flowmeter may be provided between the fibre suspension supply system and the cavity of the mould in order to measure the flow rate of the fibre suspension into the partially filed cavity.

Optionally, the moulding system comprises a conduit network between the fibre suspension supply system and the cavity, and between the pre-filling liquid supply system and the cavity, wherein the control system is configured to control the pre-filling liquid supply system and the fibre suspension supply system to control the volume of pre-filing liquid in the cavity to be greater than a volume of air in the conduit network between the cavity and the fibre suspension system. This ensures that sufficient pre-filling liquid is retained in the cavity when the fibre suspension is introduced.

Optionally, the fibre suspension supply system comprises a fibre suspension valve coupled to the conduit network and the pre-filling liquid system comprises a pre-filling liquid valve coupled to the conduit network, the moulding system further comprising a drain conduit system coupled to an exterior of the mould and having a drain valve coupled between the exterior of the mould and a drain outlet; the control system being configured to: open the pre-filling liquid valve to allow the pre-filling liquid supply system to at least partially fill the cavity with the pre-filling liquid; close the pre-filling liquid valve; and open the drain valve and open the fibre suspension valve to allow fibre suspension to be introduced into the cavity and pre-filling liquid to be removed from the cavity.

According to a second aspect of the present invention, there is provided a method of moulding a hollow moulded fibre product from a fibre suspension. The method comprises at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity, the cavity being defined by one or more internal surfaces of the mould and the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; and subsequently introducing a fibre suspension to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid. The presence of a pre-filling liquid in the cavity of the mould acts as a liquid buffer for the fibre suspension to impact, which reduces the velocity of the fibres impacting the mould. This reduces or eliminates fibres sticking in the passageways of the mould which in turn reduces mould cleaning requirements and reduces the fluffmess of the hollow moulded fibre product.

In some examples, the hollow moulded fibre product may be a precursor such as a bottle precursor. In some examples, the fibre suspension comprises pulp fibres suspended in water (or an aqueous liquid). In some examples, the pre-filling liquid comprises water or “white water” which is filtered wastewater from a previous moulding operation and which may contain a smaller number or concentration of fibres when compared with the fibre suspension.

In some examples the body of pre-filling liquid may have been allowed to settle into a standing pool prior to introducing the fibre suspension to the cavity. In other examples, the body of pre-filling liquid may be in a dynamic or turbulent state when the fibre suspension is introduced. The shape of the body of liquid may be defined by gravity, the shape of the cavity and any hydrodynamic forces resulting from the filling of the cavity with the pre-filling liquid. In some examples, the level of turbulence present in the body of pre-filling liquid when impacted by the fibre suspension may be controlled by controlling one or more of the following: the rate of filling the cavity with the prefilling liquid; the amount of pre-filling liquid added to the cavity and/or the volume of pre-filling liquid retained within the cavity prior to introducing the fibre suspension; a delay between the at least partially filling the cavity with the pre-filling liquid and introducing the fibre suspension; any draining of the body of pre-filling liquid before or during the introducing the fibre suspension.

Optionally, the method comprises at least partially filling the cavity with the prefilling liquid during a first time period; introducing the fibre suspension into the at least partially filled cavity during a second time period; and removing liquid from the cavity during a third time period. Time period-based control of the moulding system allows optimisation for various outcomes with respect to the hollow moulded fibre product, such as: increase the speed of moulding and/or throughput, improve external surface finish such as smoothness, and improve the uniformity of fibre deposition.

In some examples, some of the time periods may overlap and/or may be separated by a delay. For example, liquid may start being removed from the cavity under the action of a negative pressure source (during a third time period) when the fibre suspension is being introduced into the partially filled cavity (during a second time period) but not until after pre-filling of the cavity has been completed. . In another example, the first and second time periods may overlap such that the fibre suspension starts being introduced before filling of the cavity with the pre-filling liquid has been completed. In another example, the delay between completion of pre-filling the cavity (end of first time period) and beginning introducing the fibre suspension (start of second time period) may be set to allow the body of pre-filling liquid to settle into a substantially static condition.

Optionally, the second and third time periods overlap with each other and the first time period does not overlap with the third time period. This configuration prevents liquid from being drained from the cavity whilst the cavity is still being filled with pre-filling liquid. This increases the size and reduces the turbulence of the body of pre-filling liquid present which may improve smoothness and/or uniformity of fibre density properties of the hollow moulded fibre product. Optionally, the pre-filling liquid or the fibre suspension is received into the cavity via an inlet which is located above the cavity. Such an arrangement allows the pre-filling liquid or the fibre suspension to flow into the cavity under the assistance of gravity, from their respective pre-filling liquid supply system or fibre suspension supply system. This improves flow of the pre-filling liquid and/or fibre suspension and enables them to be more easily and/or finely controlled, improving the overall quality of the hollow moulded fibre product. This may also allow the omission of positive pressure being applied to force the pre-filling liquid and/or the fibre suspension into the cavity, which in turn simplifies the control system and the overall moulding system.

In some examples, the mould may be vertically or substantially vertically oriented. For example, where the hollow moulded fibre product is a bottle precursor, the mould may be oriented such that a neck of the bottle precursor is at the top of the mould whilst a base of the bottle precursor, which is facing the neck, is at the bottom of the mould. In some examples, a bleed valve is provided in a conduit between the fibre suspension supply system and/or the pre-filling liquid supply system to the cavity such that the cavity can be placed under atmospheric pressure. This encourages flow of fibre suspension and/or pre-filling liquid from the fibre suspension supply system and/or the pre-filling liquid supply system, respectively, towards the cavity, with or without the application of a positive pressure to the fibre suspension and/or the pre-filling liquid. In some examples, one or more pumps may be employed to force the pre-filling liquid and/or the fibre suspension into the cavity.

Optionally, a major axis of the elongate shape of the cavity is vertically oriented.

In some examples, the method may comprises applying negative pressure to the exterior of the mould whilst introducing the fibre suspension to the at least partially filled cavity. The use of negative pressure applied to the exterior of the mould accelerates removal of liquid from the cavity of the mould which may result in a faster moulding process, improved distribution of fibres and/or improved external surface finish of the hollow moulded fibre product.

Optionally, the method comprises using a flow rate of the fibre suspension into the partially filed cavity to control an amount of fibre suspension introduced into the partially filed cavity. The use of the flow rate of the fibre suspension into the partially filled cavity simplifies the dosing of fibre suspension required to mould the hollow moulded fibre product. Dosing may otherwise be difficult in the presence of the pre-filling liquid which adds mass to the mould that may confuse other dosing methods such as weighing.

Optionally, the method comprises controlling the volume of pre-filling liquid in the cavity to be greater than a volume of air in a conduit network between the cavity and a fibre suspension system used to supply the fibre suspension for introducing into the cavity. This ensures that sufficient pre-filling liquid is retained in the cavity when the fibre suspension is introduced. According to a third aspect of the present invention, there is provided a control system configured to cause a moulding system to perform a method according to the second aspect. The moulding system may be a moulding system according to the first aspect.

According to a fourth aspect of the present invention, there is provided a non- transitory storage medium storing machine-readable instructions that, when executed by a processor of a control system, cause the processor to control a moulding system to perform a method of the second aspect.

In some examples of any of the above aspects, the hollow moulded fibre product is a necked hollow moulded fibre product, such as a bottle, a jar or a type of vase. In some examples of any of the above aspects, the hollow moulded fibre product is a bottle.

According to a fifth aspect of the present invention, there is provided a receptacle manufacturing line comprising a moulding system according to the first aspect, for moulding the hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle.

The apparatus may comprise an interior coater and the at least one additional process may comprise the interior coater coating at least a portion of an interior of the product to produce an internally coated product. The apparatus may comprise a closurepart applicator and the at least one additional process may comprise the closure-part applicator applying a closure part to the product or the internally coated product to produce a closable or closed product. The apparatus may comprise an exterior coater and the at least one additional process may comprise the exterior coater coating at least a portion of an exterior of the product or the internally coated product or the closable or closed product to produce an externally coated product. The apparatus may comprise a decorator and the at least one additional process may comprise the decorator decorating the product or the internally coated product or the closable or closed product or the externally coated product to produce a decorated product. The apparatus may comprise a dryer and the at least one additional process may comprise the dryer drying the product or the internally coated product or the closable or closed product or the externally coated product or the decorated product to produce a dried product. The apparatus may comprise an evaluator and the at least one additional process may comprise the evaluator evaluating the product, the internally coated product, the closable or closed product, the externally coated product, the decorated product, or the dried product to produce an evaluated product. In some examples, the receptacle is the product, the internally coated product, the closable or closed product, the externally coated product, the decorated product, the dried product, or the evaluated product.

In some examples, the receptacle is a necked receptacle, such as a bottle, jar or a type of vase, and the receptacle manufacturing line is a necked-receptacle manufacturing line. In some examples, the receptacle is a bottle.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a receptacle, the method comprising performing a method of the second aspect to mould the hollow moulded fibre product, and then performing at least one additional process on the hollow moulded fibre product to provide the receptacle.

The at least one additional process may comprise coating at least a portion of an interior of the product to produce an internally coated product. The at least one additional process may comprise applying a closure part to the product or the internally coated product to produce a closable or closed product. The at least one additional process may comprise coating at least a portion of an exterior of the product or the internally coated product or the closable or closed product to produce an externally coated product. The at least one additional process may comprise decorating the product or the internally coated product or the closable or closed product or the externally coated product to produce a decorated product. The at least one additional process may comprise drying the product or the internally coated product or the closable or closed product or the externally coated product or the decorated product to produce a dried product. The at least one additional process may comprise evaluating the product, the internally coated product, the closable or closed product, the externally coated product, the decorated product, or the dried product to produce an evaluated product. In some examples, the receptacle is the product, the internally coated product, the closable or closed product, the externally coated product, the decorated product, the dried product, or the evaluated product. In some examples, the receptacle is a necked receptacle, such as a bottle, jar or a type of vase. In some examples, the receptacle is a bottle.

According to a seventh aspect of the present invention, there is provided a method of providing a content-containing receptacle, the method comprising providing a receptacle obtained by a method of the sixth aspect and providing the contents in the receptacle to provide the content-containing receptacle.

In some examples, the providing the contents in the receptacle comprises putting the contents into the receptacle. In contrast, in some examples, the providing the receptacle comprises providing the receptacle with the contents already present in the receptacle, thereby providing the contents in the receptacle.

The contents may be in the form of, for example, a liquid, a powder, other flowable materials, one or more solid objects, or a combination thereof. For example, the contents may be a foodstuff such as a condiment, a beverage such as an alcoholic beverage, a household care product such as a detergent or other cleaning product, a personal care product such as a hair care product or a personal cleansing product or a healthcare product or a pharmaceutical product or a cosmetics product, a fragrance product such as a perfume, a vehicle product such as motor oil, or an industrial product. Other suitable contents will be apparent to the skilled reader in view of the content of this application and their common general knowledge.

In some examples, the receptacle is a necked receptacle, such as a bottle, a jar or a type of vase. In some examples, the receptacle is a bottle.

Optionally, the method comprises closing an opening of the receptacle after the providing contents in the receptacle, and/or applying a label or indicia to the receptacle.

In some examples, the closing comprises applying a closure (such as a lid or a cap or a heat seal) to the receptacle to close the opening. In some examples, the closing comprises applying a heat seal to the receptacle and (e.g., thereafter) applying a lid or a cap to the receptacle. In some examples, the applying the label or indicia to the receptacle occurs after the providing the contents in the receptacle (that is, the label or indicia is applied to the content-containing receptacle). In other examples, the applying the label or indicia to the receptacle occurs before or during the providing the contents in the receptacle.

In some examples, the applying occurs before the closing. In some examples, the applying occurs after the closing. In some examples, the applying occurs during the closing.

According to an eighth aspect of the present invention, there is provided a receptacle obtained by a method according to the sixth aspect to contain contents.

The receptacle could be used, for example, by a person (such as a natural person or a company) who puts the contents into the receptacle, or by a person who transports the contents, or by a person who wishes to dispose of (e.g., to a consumer or end user), offer to dispose of (e.g., to a consumer or end user), import, or keep the contents whether for disposal or otherwise.

The contents may, for example, be in the form of any of those discussed above.

It will be appreciated that optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of an example receptacle manufacturing line for performing a method of manufacturing receptacles from paper pulp; Figure 2 is a schematic of an example moulding system for moulding a hollow moulded fibre product;

Figure 2A is a schematic of another example moulding system for moulding a hollow moulded fibre product;

Figures 3 A and 3B are, respectively, sectional views of the mould shown in Figure 2 and illustrating pre-filling of the mould and subsequent introduction of fibre slurry into the mould, according to different examples;

Figure 4A and 4B are, respectively, a sectional view and an enlarged sectional view of the mould shown in Figure 2 and illustrating formation of a hollow moulded product and removal of excess liquid from the mould, according to an example;

Figure 5 illustrates a method of moulding a hollow moulded fibre product according to an example;

Figure 6 illustrates a method of moulding a hollow moulded fibre product according to another example;

Figure 7 shows a non-transitory computer-readable storage medium according to an example;

Figure 8 shows a schematic cross-sectional view of a receptacle containing contents, according to an example; and

Figure 9 shows a method of providing a content-containing receptacle.

DETAILED DESCRIPTION

The following description presents exemplary embodiments and, together with the drawings, serves to explain principles of embodiments of the invention. Figure 1 shows a receptacle manufacturing line for performing a method of manufacturing receptacles, in this case necked receptacles, and more specifically in this case in the form of bottles, from paper pulp (i.e., which can form the basis of an example fibre suspension). By “necked receptacle” it is meant that the receptacle has an internal narrowing, or “neck”, between a main body portion, in which most of or all the contents of the receptacle are stored in use, and an opening through which the contents can enter or leave the receptacle in use. The internal width of the receptacle at the neck may be the same as or different to the internal width of the opening. However, the internal width of the neck is smaller than that of the main body portion, so that a shoulder is defined by and between the neck and the main body portion. This shoulder complicates manufacture of the receptacle, since it interferes with subsequent removal (and, in some cases, insertion) of whatever mould tool is inserted into the receptacle to form the internal shape of the receptacle. Examples of necked receptacles are bottles, jars, and certain types of vases. The process is merely exemplary and is provided to give context to examples of the present invention. It will be appreciated that, in other examples, the receptacle manufacturing line could be for making non-necked receptacles (i.e., receptacles without such a neck), such as bowls or trays.

Broadly speaking, the exemplary process comprises providing a fibre suspension, introducing the fibre suspension into a mould cavity of a porous first mould and expelling a liquid (such as water) from the fibre suspension to produce a hollow moulded fibre product (which may be called a wet precursor or embryo) in the mould cavity, further moulding the hollow moulded fibre product to produce a hollow further-moulded fibre product, drying and then internally-coating the hollow further-moulded fibre product to produce an internally coated product, drying the internally coated product to produce a dried product, applying a closure part to the dried product to produce a closable or closed product, externally-coating and/or decorating the closable or closed product to produce an externally coated and/or decorated product, and then drying the externally coated or decorated product to produce another dried product. As will be apparent at least from the following description, modifications may be made to the exemplary process to provide variants thereof in which other examples of the present invention may be embodied. For example, in some cases, either the internal coating or the external coating and/or decorating may be omitted. Moreover, in the present case and as indicated by the stars labelled Ins. 1 to Ins. 5 in Figure 1, the process comprises inspecting or evaluating the hollow further-moulded fibre product, the internally coated product, the closable or closed product, the externally coated or decorated product, and the dried product to produce respective evaluated products. In some examples, the receptacle is the hollow moulded fibre product, the hollow further-moulded fibre product, the internally coated product, the closable or closed product, the externally coated or decorated product, one of the dried products, or one of the respective evaluated products.

In this example, providing the fibre suspension comprises preparing the fibre suspension from ingredients thereof. More specifically, the preparing comprises providing pulp fibres, such as paper pulp fibres, and mixing the pulp fibres with a liquid to provide hydrated pulp fibres. In this example, the pulp fibres are provided in sheet form from a supplier and the liquid comprises water and one or more additives. In this example, the liquid is mixed with the pulp fibres to provide hydrated pulp fibres having a solid fibres content of lwt% to 5wt% (by dry mass of fibres). In examples, the one or more additives includes a sizing agent, such as alkylketene dimer (AKD). The hydrated pulp fibres typically comprise AKD in an amount of 0.4wt% with respect to the total dry mass of the solid fibres in the hydrated pulp fibres. In some examples, one or more additives are present in the liquid at the point of mixing the pulp fibres with the liquid. In some examples, one or more additives are included in the hydrated pulp fibres after mixing the pulp fibres with the liquid (for example, the pulp fibres are hydrated for a period of time, such as from 2 to 16 hours, and then one or more additives are supplied to the hydrated pulp fibres). The hydrated pulp fibres are passed between plates of a valley beater 11 or refiner that are in motion relative to each other. This fibrillates some, or all, of the fibres, meaning that cell walls of those fibres are caused to become partially delaminated so that wetted surfaces of those fibres comprise protruding hairs or fibrillations. These fibrillations will help to increase a strength of bonds between the fibres in the dried end product. In other examples, the valley beater 11 or refiner may be omitted.

The resultant processed pulp is stored in a vat 12 in a relatively concentrated form (for example, a solid fibres content of lwt% to 5wt%) to reduce a required storage space. At an appropriate time, the processed pulp is transferred to a mixing station 13 at which the processed pulp is diluted in further water and, optionally, mixed with one or more additives (as well as, or in place of, the one or more additives provided with the hydrated pulp fibres) to provide the fibre suspension ready for moulding. In this example, the solid fibres account for 0.7wt% of the resultant fibre suspension (by dry weight of fibres), but in other examples the proportion of solid fibres in the fibre suspension may be different, such as another value in the range of 0.5wt% to 5wt%, or 0.1 wt% to lwt%, of the fibre suspension (by dry weight of fibres). In some examples, the one or more additives mixed with the processed pulp and water includes a dewatering agent, such as modified and/or unmodified polyethylene imine (PEI), for example modified PEI sold under the trade name Polymin® SK. In some examples, the one or more additives are mixed with the water, and the water and one or more additives subsequently mixed with the processed pulp; in other examples, the processed pulp and water are mixed, and the one or more additives subsequently mixed with the processed pulp and water. The fibre suspension typically comprises Polymin® SK in an amount of 0.3wt% with respect to the total dry mass of the solid fibres. Mixing of the fibre suspension at the mixing station 13 helps to homogenise the fibre suspension. In other examples, the processed pulp or the fibre suspension may be provided in other ways, such as being supplied ready-made.

Downstream of the vat 12 and the mixing station 13 is a first moulding station that comprises a porous first mould 15. In this example, the porous first mould 15 comprises two half-moulds 14 that are movable towards and away from each other, in this case using a hydraulic ram. In this example, each of the half-moulds 14 is a monolithic or unitary tool formed by additive manufacturing (for example, 3D-printing) that defines a mould profile, and, when the half-moulds 14 are brought into contact with each other, their respective mould profiles cooperate to define the mould cavity in which the hollow moulded fibre product is to be formed. Each half-mould 14 itself defines a smaller moulding cavity and, when brought into cooperation with a second half-mould 14, the smaller moulding cavities combine to provide the overall mould cavity. The two halfmoulds 14 may themselves be considered “splits” or “moulds” and the overall porous first mould 15 may be considered a “split-mould” or, again, a “mould”. In other examples, the porous first mould 15 may comprise more than two splits 14, such as three, four or six splits, that cooperate to define the moulding cavity.

In Figure 1, the fibre suspension (also known as slurry) is top-filled into the porous first mould 15, in contrast to moulding processes that dip a mould in slurry. The fibre suspension is drawn under vacuum via a line 16 and into the porous first mould 15, with excess suspending liquid being drawn through the porous first mould 15 under vacuum via a line 18 into a tank 17. Shot mass may be controlled by measuring (for example, weighing) the amount of liquid drawn into the tank 17. A weight scale platform supporting the tank 17 is visible in Figure 1. Once a required amount (for example, a predetermined volume, such as 10 litres, or a predetermined mass, such as 10 kilograms) of liquid has been collected in the tank 17, suction of the suspending liquid through the porous first mould 15 is stopped and the first mould 15 is opened to ambient air. In this example, the suspending liquid drawn with the fibre suspension in line 16 is water, or predominantly water (as additives may also be present). The liquid drawn under vacuum via the line 18 and into the tank 17 is substantially free of fibres, since these are left behind against the walls of the porous first mould 15 to form the hollow moulded fibre product.

In one example, in order to remove further suspending liquid (for example, water) from the hollow moulded fibre product, and form or consolidate the three-dimensional shape of the product, high pressure fluid (such as compressed air) is introduced into the first mould 15 to compress the fibre suspension against the cavity wall of the first mould 15. This process strengthens the product so that it can be handled, and displaces water from in between the fibres, thereby increasing the efficiency of a subsequent drying process. The fluid is regulated using a hydraulic pump 20. The pump 20 has a cylinder that displaces the fluid in a line 21 into the first mould 15. In an alternative example, an impermeable inflation element in the form of a collapsible bladder is inserted into the first mould 15 and expanded, by introduction of a fluid into the bladder from the line 21, to act as an internal high-pressure core structure for the first mould 15. In such an alternative, the fluid within the line 21 is preferably non-compressible, such as water or oil, although in other examples it could be a compressible fluid, such as air. Water has the advantage over other non-compressible liquids that any leaking or bursting of the bladder will not introduce a new substance to the system (since the suspending liquid is already water, or predominantly water).

Demoulding occurs when the first mould 15 opens for removal of the self- supporting hollow moulded fibre product 22. Mould cleaning 23 is preferably performed subsequently, to remove any remaining small fibres and/or other debris and maintain a porosity of the porous first mould 15. In this example, a radially firing high-pressure jet is inserted into the mould cavity while the first mould 15 is open. This dislodges debris from the wall of the mould cavity. Alternatively, or in addition, water from the tank 17 is pressurised through the back of the porous first mould 15 to dislodge entrapped fibres and/or other debris. Water is drained for recycling back to an upstream part of the system. It is noteworthy that cleaning is important for conditioning the first mould 15 for re-use. The first mould 15 may appear visibly clean after removal of the receptacle, but its performance could be compromised without cleaning.

According to Figure 1, the hollow moulded fibre product 22 is subsequently transported to a second moulding station where, in a, for example, aluminium, mould 25, pressure and heat are applied for thermoforming a desired neck and surface finish, optionally including embossed and/or debossed surface features. After two halves of the mould 25 have closed around the product 22, a pressuriser is engaged. For example, a bladder 26 (for example, a thermoforming bladder 26) is inserted into the product 22. The bladder 26 is inflated with a pressurised fluid supplied via a line 27 by a pump 28 . The pressurised fluid is preferably a non-compressible fluid such as water or oil, although in other examples it could be a compressible fluid such as air. In other examples, during supply, the pressurised fluid is heated with, for example, a heater or, alternatively, is cooled with, for example, a heat exchanger. An external mould block 24 of the mould 25, and/or the mould 25 itself, is also, or alternatively, heated in some examples. After thermoforming, a state of the product 22, which may now be considered a hollow further- moulded fibre product, is considerably more rigid, with more compressed side walls, as compared with the state of the product 22 at demoulding from the first mould 15.

A drying stage 30 (for example, a microwave drying process or other drying process) is performed on the product 22 downstream of the thermoforming, as shown, to provide a dried product. In one example, the drying stage 30 is performed before thermoforming to provide a dried product. However, moulding in the mould 25 requires some water content to assist with bonding during the compression process. The drying may be performed using a dryer, such as a machine that acts to cause drying of the product or simply a shelf or other support on which the product 22 rests while drying.

The product 22 is then subjected to an internal-coating stage during which, in this example, an interior coater in the form of a spray lance 31 is inserted into the product 22 and applies one or more surface coatings to internal walls of the product 22 to produce an internally coated product. In another example, the product 22 is instead filled with and subsequently drained of a liquid that coats the internal walls of the product 22. In practice, such coatings provide a protective layer to prevent egress of contents into the bottle wall, which may permeate and/or weaken it. Coatings will be selected dependent on the intended contents of finished receptacle, for example, a beverage, foodstuff, detergent, lubricant, pharmaceutical product, etc. In this example, the internally coated product 22 is then subjected to a curing or drying process 32, which can be configured or optimised dependent on the internal coating, for example, drying for twenty -four hours at ambient conditions or by a flash drying method. The drying again may be performed using a dryer, such as a machine that acts to cause drying of the product or simply a shelf or other support on which the product 22 rests while drying. Following the drying, the coated product 22 is considered another dried product.

A closure or mouth forming process is then performed on the product 22 by a closure-part applicator to produce a closable or closed product. For example, as shown in Figure 1, a neck fitment 33 is affixed to the dried product. This results in the product being closable subsequently by positioning of a cap, lid or other closure relative to the neck fitment. An exterior coating and/or decoration is then applied to the product 22 by an exterior coater and/or a decorator, respectively, as shown in the further stage 34, to produce an externally coated and/or decorated product. In one example, the product 22 is dipped into a liquid to coat its outer surface, as shown in Figure 1. In another example, the outer surface receives the external coating in a different manner. The coating and/or decoration may cover all or only part of an external surface of the product. The product 22 is then allowed to dry in warm air to produce another dried product. In other examples, the drying may be performed using a dryer such as one of those discussed above.

The product 22 may therefore be fully formed, considered the end “receptacle”, and ready to accept contents therein. In other examples, the receptacle may be fully formed without the neck fitment 35 being affixed and/or without the interior coating being applied and/or without the exterior coating being applied and/or without the decoration being applied and/or immediately after one of the drying processes or one of the inspecting and/or evaluating processes. For example, in some cases, the product is provided with the closure part by moulding the closure part during moulding of the product at the first moulding station and/or the second moulding station.

Reference is now directed to Figure 2, which is a schematic diagram of a moulding system 100 according to an example. The moulding system 100 shown is configured for moulding a hollow moulded fibre product 22 (shown in dashed outline) from a fibre suspension, during use of the system 100. The hollow moulded fibre product 22 and/or the fibre suspension may, for example, be as described above with reference to Figure 1. In this example, the hollow moulded fibre product 22 is, or will be (after further processing), a bottle. However, with suitable modifications to the system such as using a different mould, the hollow moulded fibre product 22 can be or can be used to make (with further processing) a jar, a vase, or another necked or non-necked receptacle for example.

As shown in Figure 2, the system 100 comprises a mould 110 having a cavity 112, within which the hollow moulded fibre product 22 is moulded, during use of the system 100. As also shown, the mould comprises internal surfaces 114 that together define this cavity 112. As will be discussed below, the mould 110 further comprises a plurality of passageways or pores 111, 111 A (not shown in Figure 2), each of which provides fluid communication between one of the internal surfaces 114 of the mould 110 and an external surface of the mould 113. This allows liquid within the cavity 112 to be removed to an exterior of the mould 113. For example, following introduction into the cavity of a fibre suspension containing pulp fibres carried in a liquid medium such as water, the passageways of the mould allow the liquid medium to be removed from the cavity leaving deposits of pulp fibre on the internal surfaces of the mould.

The mould 110 also comprises an inlet 116 opening into the cavity 112 in order to allow the introduction of a fibre suspension. In this example, the inlet 116 is provided in a neck portion 115 of the mould which is facing a base portion 117 of the mould. The cavity 112 has an elongate shape with the inlet 116 located at one longitudinal end of the elongate shape. The mould 110 is configured for moulding a necked hollow moulded fibre product as a precursor for a bottle. However, other moulds with differently shaped cavities may alternatively be used for moulding different types of precursors. In some examples more than one inlet may be available, in which case the fibre suspension may be delivered in one or more of these inlets into the cavity 112.

The mould 110 may also be associated with structural components 119 such as a frame to provide structural support and accurate positioning of the mould 110. In this example, a major axis of the elongate shape of the cavity 112 is vertically oriented, however other orientations may alternatively be employed. The structural components may contain the exterior of the mould 113 in order to collect liquid received from the cavity 112 via the passageways 111, 111A. The mould 110 may be formed from two separate half-moulds, or parts, similarly to the mould 15 shown in Figure 1. However, this is by no means essential and in other examples the mould 110 could be formed of three, four, etc., parts.

The moulding system 100 comprises a drain conduit 170 having a drain valve 172 and a negative pressure source 174, such as a vacuum pump. The drain conduit is arranged to drain liquid from the exterior of the mould 113. The use of the vacuum pump 174 increases the rate of removal of liquid from the exterior of the mould and in turn from the cavity 112. This helps to ensure that liquid is substantially removed from the cavity in order to form the hollow moulded fibre product 22. In alternative examples, the negative pressure source 174 and/or drain valve 172 may be omitted, with the moulding system 100 relying on gravity to remove liquid from the cavity 112 and the exterior of the mould 113. The moulding system 100 comprises a fibre suspension supply system 130 having a fibre suspension reservoir 132, a flow meter 136 and a fibre suspension valve 138. In use the fibre suspension reservoir 132 may be provided with a fibre suspension 134, such as a pulp fibre slurry. The fibre suspension reservoir 132 may be any suitable arrangement or system such as the vat 12 and mixing station 13 of Figure 1. The fibre suspension valve 138 controls the flow of fibre suspension towards the mould 110. The flow meter 136 provides an indication of the rate of flow of fibre suspension through the fibre suspension valve 138. The use of a device or method for measuring the flow rate of the fibre suspension simplifies dosing or the amount of the fibre suspension to be supplied to the mould 110. However in alternative examples, different devices or methods for dosing of the fibre suspension may be employed. In some examples, the fibre suspension supply system 130 may additionally comprise a pump (not shown) to apply positive pressure to fibre suspension delivered to the mould 110.

The moulding system 100 comprises a pre-filling liquid supply system 140 having a pre-filling liquid reservoir 132, a pre-filling liquid pump 146 and a pre-filling liquid valve 138. In use the pre-filling liquid reservoir 132 may be provided with a pre-filling liquid 144 such as water or recovered waste-water from the moulding system 100 and/or other parts of a receptacle manufacturing line such as that of Figure 1. The recovered waste-water may comprise a low concentration of fibres and is known as white water. Use of this white water as the pre-filling liquid reduces wastage of water and may improve overall efficiency of the receptacle manufacturing line. The pre-filling liquid valve 148 controls the flow of pre-filling liquid towards the mould 110. In use, the pre-filling liquid is provided to the mould 110 prior to the introduction of the fibre suspension, as described in more detail below.

The moulding system 100 comprises a conduit network 160 arranged to deliver fibre suspension 134 from the fibre suspension system 130 and pre-filling liquid 144 from the pre-filling liquid system 140 into the cavity 112 of the mould 110. The conduit network 160 is coupled to the fibre suspension valve 138 and the pre-filling liquid valve 148. The conduit network 160 terminates in or about the inlet 116 of the mould 110 and may comprise a plug or other fitting adapted to mate with the neck 115 of the mould 110, to avoid spillage of the fibre suspension or pre-filling liquid. The conduit network 160 comprises a bleed valve 162 which couples the conduit network to atmosphere. Opening the bleed valve 162 may facilitate the flow of the fibre suspension and/or the pre-filling liquid into the cavity 112.

In alternative examples, where the mould comprises two or more inlets into its cavity, the pre-filing liquid and fibre suspension may be conducted to different inlets by the conduit network.

Figure 2A illustrates an example moulding system 100A having multiple inlets into a cavity of the mould. Features in common to the moulding system 100 have the same reference numerals. For simplicity internal surfaces 114 and the hollow moulded fibre product 22 are not illustrated but are still present in this example. Reference is made to the preceding description of Figure 2 for detailed description of these omitted and common features.

The example 100A of Figure 2A differs from that of Figure 2 in having half moulds 110A, HOB which, when joined together, form the cavity 112, and are referred to herein as mould 110A, HOB when in this state. The example 100A of Figure 2A also differs from that of Figure 2 in having the pre-filling liquid and the fibre suspension being delivered into the cavity of the mould 110A, 110B via different conduit routes and inlets into the cavity.

The moulding system 100A comprises a modified conduit network having two conduit branches 160 A and 160B. A first conduit branch 160 A is arranged to deliver fibre suspension 134 from the fibre suspension system 130 into the cavity 112 of the mould 110A, 110B. The first conduit branch 160A is coupled to the fibre suspension valve 138 and terminates in or about the inlet 116 of the mould 110A, HOB. The inlet 116 may be associated with a plug or other fitting adapted to mate with the neck 115 of the mould 110 A, HOB, to avoid spillage of the fibre suspension. The first conduit branch 160A comprises a bleed valve 162 which couples the first conduit branch 160A to atmosphere. Opening the bleed valve 162 may facilitate the flow of the fibre suspension and/or the pre-filling liquid into the cavity 112. A second conduit branch 160B is arranged to deliver pre-filling liquid 144 from the pre-filling liquid system 140 into the cavity 112 of the mould 110A, HOB. The conduit branch 160B is coupled to the pre-filling liquid valve 148 and terminates into inlets 118A, 118B in the mould 110A, HOB. The inlets 118A, 118B for the pre-filling liquid may be formed in a respective base portion 117A, 117B of each half mould 110A, HOB. In other variations, a single inlet for the pre-filling liquid in one or both base portions may be formed, and/or the inlets for the pre-filling liquid may be formed in the sides of the mould 110A, 110B.

References to moulding system 100 and/or mould 110 which follow may be replaced respectively with moulding system 100 A and/or mould 110A, 110B.

The bleed valve 162 in the moulding system 100, 100A may be located above the fibre suspension valve 138 to facilitate bleeding of air from this part of the conduit network 160, 160 A.

The moulding system 100 (or 100A) also comprises a control system 150 configured to control the pre-filling liquid supply system 140 and the fibre suspension supply system 130. In an example, the control system 150 may be coupled to control the fibre suspension valve 138, the pre-filling liquid pump 146, the pre-filling liquid valve 148, the bleed valve 162, the drain valve 172 and the negative pressure source 174. The control system 150 is also coupled to receive data indicating a flow rate of the fibre suspension from the flow meter 136. The control system 150 is configured to control the pre-filling liquid system 140 to at least partially fill the cavity 112 with pre-filling liquid to form a body of pre-filling liquid in the cavity. The control system 150 is configured to control the fibre suspension system 130 subsequently to introduce fibre suspension into the at least partially filled cavity 112 where it impacts the body of pre-filling liquid. This combination of actions may be implemented by controlling the opening and closing of the fibre suspension valve 138 and the pre-filling liquid valve 148 as described in more detail below. Control by the control system 150 of the pre-filling liquid pump 146, bleed valve 162, drain valve 172 and/or negative pressure source 174 may also facilitate achieving this combination of actions. At least partially filling the cavity 112 with pre-filling liquid prior to the introduction of fibre suspension, reduces or eliminates fibres sticking in the passageways or pores of the mould 110. The pool of pre-filling liquid acts as a liquid buffer against the incoming fibre suspension, reducing the velocity of the fibres before they impact the internal surfaces 114 of the mould. The reduction or elimination of fibres stuck in pores of the mould reduces mould cleaning requirements and also improves the smoothness of the exterior surface of the hollow moulded fibre product - this is also known as reducing the “fluffmess” of the exterior surface. A smooth exterior surface to the hollow moulded fibre product improves downstream processing and results in a better finished receptacle.

Reference is now directed to Figure 3A, which is a sectional view of the mould 110 shown in Figure 2. A single passageway or pore 111 is shown for simplicity. However, it will be appreciated that in practice a large number of pores 111 may extend across each internal surface 114 to an external surface 113 of the mould. In an example, the pores 111 are distributed across the mould to provide continuous porosity.

Figure 3A illustrates the cavity 112 being partially filled with pre-filling liquid to form a body of pre-filling liquid 180A together with a stream of fibre suspension 182 being introduced into the cavity 112 via the inlet 116. It will be appreciated that at least some of the stream of fibre suspension 182 will impact the body of pre-filling liquid 180A before impacting the internal surfaces 114 of the cavity 112. By impacting with the body of pre-filling liquid 114, fibres within the stream of fibre suspension are slowed by their travel through the pre-filling liquid, which in turn reduces their velocity prior to impacting pores 111 on the inner surfaces 114 of the mould 110.

The effect of high velocity impact of fibres into pores 111 may be most pronounced at the base 117 of the mould 110 as the corresponding inner surface 114 is directly facing the incoming stream of fibre suspension 182 from the inlet 116. Therefore, in some examples, it may be sufficient to have a body of pre-filling liquid 180A covering the inner surface of base portion 117 without needing the body of pre-filling liquid 180 A to extend up the side wall inner surfaces 114 or the inner surfaces of the neck portion 115. However, in other examples, the body of pre-filling liquid 180A may extend up to and into the neck portion 115. The shape of the body of pre-filing liquid may be defined by gravity, the shape of the cavity and any hydrodynamic forces resulting from the filling of the cavity with the pre-filling liquid. The pre-filling liquid may have been allowed to settle into a substantially static or standing pool 180A prior to introducing the fibre suspension to the cavity, as illustrated in Figure 3A. In other examples, the body of pre-filling liquid may be in a dynamic or turbulent state when the fibre suspension is introduced, as illustrated in Figure 3B.

Figure 3B is also a section of the mould of Figure 2 and illustrates the pool of prefilling liquid 180B being in a turbulent state. This may be the result of the pre-filling liquid having only just finished entering the cavity 112 and without any subsequent settling time. However, it can be seen that the stream of fibre suspension 182 will still impact with pre-filling liquid thereby reducing the velocity of fibres impacting the pores 111 of the inner surfaces of the mould 110.

The control system 150 is configured to control the flows of pre-filling liquid and fibre suspension into the cavity in order to provide this liquid buffering effect. In some examples, a settling time period may be introduced between completion of filling the cavity with pre-filling liquid and commencement of introducing the fibre suspension into the cavity. Depending on the length of the settling time, the body of pre-filling liquid may be more like that illustrated in Figure 3A, or more like that illustrated in Figure 3B. In some examples, filling of the cavity with pre-filling liquid and introducing the fibre suspension may overlap in time, with commencement of introducing the fibre suspension into the cavity being after commencement of filling the cavity with pre-filling liquid but before filling of the cavity with pre-filling liquid has been completed.

Figure 4A and 4B are respectively a sectional view and an enlarged sectional view of the mould shown in Figure 2. Figure 4A illustrates formation of a hollow moulded fibre product and removal of excess liquid from the mould, according to an example. Figure 4B illustrates the deposition of fibres about a pore of the mould.

Referring to Figure 4A, following at least partially filling of the pre-filling liquid and introduction of the fibre suspension, a liquid mixture 184 is shown remaining inside the cavity 112 of the mould 110. This liquid mixture 184 may be a mixture of the prefilling liquid and the fibre suspension, in differing relative concentrations depending on factors such as the relative timing of the filling of the cavity with the pre-filling liquid and filling of the cavity with the fibre suspension, as well as the rate and duration of removal of the liquid mixture 184.

The liquid mixture 184 in the cavity 112 is removed to an exterior of the mould 113 via a plurality of passageways or pores 111 A in the mould 110 - shown as removed liquid 186 - leaving behind fibres from the fibre suspension. Again, for simplicity only a single passageway 111A is illustrated, but it will be understood that the mould may comprise more than one such passageway distributed across the internal surfaces of the cavity 112. The deposition of these fibres against the inner surfaces of the cavity 112 forms a hollow moulded fibre product 22, shown in dashed outline. Removed liquid 186 is simply illustrated from the single illustrated passageway or pore 111A in the base 117 of the mould. However, it will be understood that such removed liquid may be removed using multiple pores across different parts of the mould 110, including for example about the neck 115 and sides of the mould.

Referring also to Figure 4B, deposition of the fibres 188 A, 188B on an inner surface 114 of the mould 110 about a passageway or pore 111A is illustrated. As noted above, at least partially filling the cavity 112 with a pre-filling liquid prior to introducing fibre suspension acts as a liquid buffer against the incoming fibre slurry. This reduces the velocity of the fibres in the fibre suspension impacting the internal surfaces 114 and pores 111 A of the mould 110. This in turn reduces fibres 188B from lodging in the pores 111 A and instead encourages fibres 188 A to settle against the inner wall and across the pores 111A in a direction substantially parallel to the surface of the inner surface 114 of the mould 110. In doing so, and given their elongate shape, the fibres 188A tend to matt together forming a coherent fibre-based structure defined by the shape of the inner surfaces of the cavity of the mould.

After the liquid mixture 184 has been substantially removed from the cavity 112, the mould may be opened to remove the newly formed hollow moulded fibre product 22. Following removal of the hollow moulded fibre product 22, the mould may then be closed again ready for the next moulding cycle in which the cavity of the mould is again at least partially filled with pre-filling liquid and fibre suspension again introduced into the partially filled cavity.

By avoiding or reducing fibres 188B lodging in the pores 111 A in a direction not substantially parallel to the adjacent internal surface of the cavity, the smoothness of the outer surface of the hollow moulded fibre product 22 is improved. This is because the hollow moulded fibre product 22 will have a lower number of fibres 188B extending orthogonally outwards from the outer surface of the product 22 when this is removed from the mould 110. In addition, a reduction in the number of fibres 188B lodged in pores 111A of the mould reduces the need to remove these in a mould cleaning process, or reduces the frequency with which mould cleaning is required.

Figure 5 illustrates a method 200 of moulding a hollow moulded fibre product according to an example. The hollow moulded fibre product may be the bottle precursor 22 provided by the moulding system 100, 100A described above with reference to Figures 2 - 4B. However, the method 200 may be used to mould other types of hollow moulded fibre products and/or to control different moulding systems. The method 200 may be implemented using the moulding system 100 of Figure 2, the moulding system 100 A of Figure 2A, and/or in conjunction with the mould 15 of Figure 1.

The method 200 comprises, at block 210, at least partially filling a cavity of a mould with a pre-filling liquid to form a body of pre-filling liquid in the cavity. This process 210 may be performed in a moulding system following closing of a multi -part mould to form a cavity defining the shape of a hollow moulded fibre product. The body of pre-filling liquid may be in a static or turbulent state and may be defined by gravity, the shape of the cavity and any hydrodynamic forces resulting from the introduction of the pre-filling liquid into the cavity or the removal of the pre-filling liquid from the cavity through pores in the mould. The level or amount of pre-filling liquid in the cavity may be controlled by the rate and duration of adding pre-filling liquid to the cavity. In some examples, the level or amount of pre-filling liquid in the body may range from completely filling the cavity to a much smaller non-film body covering only part of an inner surface of the cavity. In one example, the process of at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity may be performed over a first time period , which may be referred to as a pre-filling time period.

A desired volume of pre-filling liquid or a desired fill level of pre-filling liquid within the cavity of the mould may be achieved by using the pre-filling time period together with a predetermined flow rate of the pre-filling liquid. In other examples, a dosing mechanism may be used to deliver a predetermined volume or weight of pre-filling liquid into the cavity of the mould.

The method, at block 220, comprises introducing fibre suspension into the at least partially filled cavity such that some of the fibre suspension impacts the body of prefilling liquid. As described previously, the presence of pre-filling liquid between the incoming fibre suspension and inner surfaces of the cavity reduces the velocity with which the fibres impact these inner surfaces and the pores they contain. In some examples, only some of the cavity may be filled with pre-filling liquid such that the body is formed about an inner surface(s) of the cavity at a location opposite the incoming fibre suspension. In other examples, it may be preferable to have the cavity substantially filled with pre-filling liquid when introducing the fibre suspension. In one example, the process of introducing the fibre suspension into the cavity may be performed over a second time period.

The cavity is at least partially filled with pre-filling liquid prior to the introduction of the fibre suspension. In some examples the pre-filling liquid may continue to be added after starting to introduce the fibre suspension; that is, the first and second time periods overlap. In other examples, the fibre suspension may be introduced to the cavity immediately after the pre-filling liquid has stopped being added to the cavity; that is, the first and second periods are adjacent. In other examples, a delay may be introduced between completion of block 210, and the starting of block 220; that is, the delay may correspond to a delay time period between the first and second time periods. This delay may allow the body of pre-filling liquid to settle into a more static or standing state of liquid within the cavity, prior to the introduction of the fibre suspension. Various other processes may be performed in addition to those illustrated, including for example one or more of the processes described with respect to the receptacle manufacturing line of Figure 1 and/or the method 300 described below with respect to Figure 6. In some examples, removal of liquid from the cavity may be performed during a removal time period, also referred to as a third time period. The porous nature of the mould will allow liquid to be removed from the cavity under the influence of gravity. In some examples, a negative pressure may be applied to an exterior of the mould to increase the rate of removal of the liquid from the cavity. This negative pressure may be applied during both of blocks 210 and 220, or only over block 220 or parts of these blocks. For example, negative pressure may be applied only when the fibre suspension is being introduced but not when the pre-filling liquid is being added.

The application of negative pressure may be performed over a fourth time period which may be the same as, or less than the third time period. The third time period (and fourth time period if different) may be a predetermined time period which has previously been determined experimentally or otherwise, and may correspond with the cavity being substantially removed of liquid leaving the hollow moulded fibre product. Following the third time period, the mould may then be split into its constituent parts to allow the hollow mould fibre product to be removed and a new moulding cycle to be started.

Figure 6 illustrates a method 300 of moulding a hollow moulded fibre product according to another example. This method 300 may be performed using the moulding system 100 of Figures 2 and therefore reference is also made to this Figure. The method 300 may be implemented by the control system 150 controlling the various parts of the moulding system 100 previously described. The method 300 may also be performed using the mould 15 in the receptacle manufacturing line of Figure 1. One or more blocks of the method 300 may in some examples correspond with one or more blocks of the method 200 described in Figure 5.

The method 300 comprises, at block 310, opening the bleed valve 162 to the atmosphere. This means that the conduit network 160 and the cavity 112 are under atmospheric pressure. At block 320, the pre-filling liquid valve 148 is opened and/or the pre-filling liquid pump 146 is activated. Pre-filling liquid 144 then begins to flow from the pre-filling liquid reservoir 142, under gravity and/or the action of the pre-filling liquid pump 146, through the conduit network 160 and into the cavity 112 via the inlet 116. The cavity then begins to fill with pre-filling liquid to form a pool of pre-filling liquid which at least partially fills the cavity.

At block 330, the pre-filling liquid valve 148 is closed. This process may be performed a first time period after opening the valve 148 however other control approaches may be used such as controlling the opening and closing of the valve 148 based on a rate of pre-filling liquid flowing into the cavity or by monitoring the weight of the pre-filling liquid reservoir 142 and/or the mould 110. If used, the pre-filling pump 146 is also stopped at this point.

At block 340, the bleed valve 162 is closed.

In some examples, the volume of pre-filling liquid in the cavity may be controlled to be greater than the volume of air in the conduit network 160 between the fibre suspension valve 138 and the inlet 116 of the cavity 112. This ensures that pre-filling liquid is still present in the cavity when the fibre suspension is introduced into the cavity 112.

In some examples, the volume of air in the conduit network 160 and/or the cavity 112 is minimised prior to introducing the pre-filling liquid. This may result in a vacuum or partial vacuum within these spaces prior to introducing the pre-filling liquid.

The first, second, third and fourth time periods referred to in relation to Figure 6 correspond with these periods in relation to Figure 5, though the durations may be the same or different. Some features of the method 300 of Figure 6 may be introduced into the method 200 of Figure 5 and vice versa in some examples.

In some examples, the amount of pre-filling liquid introduced into the cavity may be controlled to exceed the volume of the cavity. In some examples, the pre-filling liquid may extend into the conduit network 160, 160A above the cavity 112. This may beneficially minimise the volume of air in this part of the moulding system 100, 100A prior to the introduction of fibre suspension. The pre-filling liquid may extend up to the fibre suspension valve 138. A delay may be introduced between closing the pre-filling liquid valve 148 and closing the bleed valve 162 in order to allow time for air bubbles entrained in the pre-filling liquid to be removed from the moulding system 100, 100 A via the bleed valve 162. When using the moulding system 100A of Figure 2A, the pre-filling liquid floods the cavity from the base portions 117A, 117B upwards. Once the cavity is filled, the pre-filling liquid may then move into the first conduit branch 160 A.

At block 350, the fibre suspension valve 138 is opened. This may follow immediately after closing of the pre-filling liquid valve 148 (and/or the bleed valve 162). Alternatively, a delay may be implemented between closing the pre-filling liquid valve 148 and opening of the fibre suspension valve 138, for example to allow the pre-filling liquid in the cavity 112 to reach an appropriately settled state. Opening of the fibre suspension valve 138 allows fibre suspension in the fibre suspension reservoir 132 to flow through the conduit network 160, 160A into the cavity 112 via the inlet 116.

Depending on the amount of retained pre-filling liquid, the fibre suspension may travel through air into the cavity 112 before impacting the pre-filling liquid, or the fibre suspension may meet the pre-filling liquid in the conduit network 160, 160 A prior to entering the cavity 112. In the latter case, the impact between the fibre suspension and the pre-filling liquid in the cavity 112 is less turbulent and may improve the smoothness of the fibre moulded product and/or reduce the amount of fibres stuck in the pores of the mould 110, 110A, HOB.

At block 360, the negative pressure source or vacuum pump 174 is started. If used, the drain valve 172 is also opened. This puts the exterior of the mould under negative pressure encouraging removal of liquid from inside the cavity towards the drain conduit 170. The liquid removed via the drain conduit 170 may either be removed from the moulding system 100 or may be recycled by conducting the drained fluid back into the pre-filling reservoir 142. Filtering may be used to remove fibres that have travelled through the pores of the mould 110. Such pre-filling liquid 144 may be referred to as white water.

In other examples, the use of negative and positive pressure may be varied. For example, the negative pressure source 174 may be applied earlier to encourage the prefilling liquid into the cavity, instead of or in addition to the use of positive pressure from the pre-filling liquid pump 146. In other examples a positive pressure source may be provided above the cavity to put the mould under positive pressure encouraging removal of liquid from inside the cavity towards the drain conduit 170.

At block 370, the fibre suspension valve 138 is closed. This may be based on a second time period after opening of the fibre suspension valve 138 in order to provide an appropriate dose of fibre suspension into the cavity to allow moulding of a hollow moulding fibre product having desired properties such as a preferred thickness and distribution of fibres. Alternatively or additionally, accurate dosing of fibre suspension into the cavity may be achieved by monitoring the flow meter 136 which monitors the flow rate of fibre suspension through the fibre suspension valve 138. The measured flow rate may be used to adjust the second time period during which the fibre suspension valve 138 remains open, in order to ensure accurate dosing. In a further alternative, the weight of the fibre suspension reservoir 130 and/or the mould 110 may be monitored and used to control closing of the fibre suspension valve 138.

At block 380, the negative pressure source or vacuum pump 174 is stopped and/or the drain valve 172 is closed. This process may be performed for a predetermined period (for example the fourth time period previously mentioned) following closing of the fibre suspension valve 138. This allows time for liquid to be substantially removed from the cavity, leaving fibres deposited on the inner walls of the cavity to form the hollow moulded fibre product. In an alternative example, the flow rate of removed liquid in the drain conduit 170 may be monitored and the vacuum pump 174 stopped and/or the drain valve 172 closed when this flow rate falls below a threshold.

In some examples, a third time period, corresponding to removal of liquid from the cavity, may be used to control one or more components of the moulding system 100. In some examples, the third time period may correspond to the period between opening the pre-filling liquid valve at block 320 and closing the drain valve at block 380. In other examples, the third time period may correspond to the period between opening the fibre suspension valve at block 350 and closing the drain valve at block 380.

Synchronising control of the various system components above the cavity, such as bleed valve and slurry valve, with control of system components below the cavity, such as the drain valve, promotes a smooth transition from pre-filling liquid to fibre suspension. This may further improve smoothness of the resulting moulded fibre product and reduce fibres being stuck in pores of the mould.

Whilst the cavity 112 has been described as having an elongate shape with an inlet 116 at one longitudinal elongate end of the elongate shape, other cavity shapes may alternatively be used in other examples. Similarly, whilst a major axis of the elongate shape has been described as being vertically oriented, other orientations are possible. It will be appreciated that many other variations are possible in other examples, such as using only positive pressure sources for fibre suspension and pre-filling liquid delivery, or only a negative pressure source for both fibre suspension and pre-filling liquid delivery.

It will be appreciated that there is provided a control system 150 that is configured to cause a pre-filling liquid system 140 to at least partially fill a cavity of a mould with a pre-filling liquid from the pre-filling supply system to form a body of pre-filling liquid in the cavity. Also provided is a control system 150 that is configured to cause a fibre suspension system 130 to introduce a fibre suspension from the fibre suspension supply system to cavity of a mould at least partially filed with a body of pre-filling liquid, such that at least some of the fibre suspension impacts the body of pre-filling liquid.

Figure 7 shows a schematic diagram of a non-transitory computer-readable storage medium 800 according to an example. The non-transitory computer-readable storage medium 800 stores instructions 830 that, if executed by a processor 820 of a control system 810, cause the processor 820 to perform a method according to an example. In some examples, the control system 810 is or comprises the control system 150 as described above. The instructions 830 comprise: - At 831 : at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity. This may be implemented by controlling a pre-filling liquid system and the cavity may be defined by one or more internal surfaces of the mould, the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould.

- At 832: subsequently introducing a fibre suspension to the at least partially filled cavity, such that at least some of the fibre suspension impacts the body of pre-filling liquid. This may be implemented by controlling a fibre suspension system.

In other examples, the instructions 830 comprise instructions to perform any other example methods described herein.

It will also be appreciated that there also is provided a receptacle manufacturing line (such as that shown in Figure 1) comprising a moulding system for moulding a hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle. Similarly, also provided is a method of manufacturing a receptacle, the method comprising a method of moulding a hollow moulded fibre product, and then performing at least one additional process on the hollow moulded fibre product to provide the receptacle. Examples of the “at least one additional process” are described above with reference to Figure 1.

Also provided, as a result of the content of the present application, is use of a receptacle obtained by any of the methods described herein to contain contents. An example such receptacle 900, in the form of a necked receptacle and specifically a bottle, containing contents 910 is shown in Figure 8. The use could be, for example, by a person who puts the contents into the receptacle, by a person who transports the contents, or by a person who wishes to dispose of (for example, to a consumer or end user), offer to dispose of (for example, to a consumer or end user), import, or keep the contents whether for disposal or otherwise. The contents could, for example, be any one or more of the example contents described herein. Also provided is a method of providing a content-containing receptacle. An example such method 1000 is shown in Figure 9. The method 1000 comprises providing 1010 the receptacle, in the form of a necked receptacle and specifically a bottle, and then providing 1020 the contents in the receptacle. In this example, block 1020 follows block 1010, so that block 1020 comprises putting the contents into the receptacle that has been provided at block 1010. However, in some other examples, blocks 1010 and 1020 are performed concurrently, so that the providing 1010 the receptacle comprises providing the receptacle with the contents already present in the receptacle. The contents could, for example, be any one or more of the example contents described herein. The method 1000 also comprises closing 1030 an opening of the receptacle after block 1020, and applying 1040 a label or indicia to the receptacle after block 1030. In this example, block 1030 involves applying a heat seal to the opening and then screwing a cap or lid onto the receptacle, and block 1040 comprises adhering a label onto the receptacle.

In respective other examples, the order of blocks 1030 and 1040 is reversed, blocks 1030 and 1040 are performed concurrently, block 1030 is omitted, and block 1040 is omitted. In some examples, block 1040 occurs before block 1020, orblock 1040 occurs during block 1020. For example, in some cases, the label or indicia is applied to the receptacle, then the contents are provided in the receptacle, and then the receptacle is closed.

It will be appreciated that the method 1000 could be performed by the same party that manufactures the receptacle, for example so that block 1010 comprises the method discussed above with reference to the manufacturing line shown in Figure 1. Alternatively, the method 1000 could be performed by a different party to that which manufactures the receptacle. In such an alternative, the different party performs block 1010 by way of obtaining the receptacle from the party that manufactures the receptacle (such as by way of the method discussed above with reference to Figure 1) or from an intermediary.

Example embodiments of the present invention have been discussed, with reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMS:

1. A moulding system for moulding a hollow moulded fibre product from a fibre suspension, the moulding system comprising: a mould comprising one or more internal surfaces that define a cavity, within which the hollow moulded fibre product is moulded in use, and a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; a fibre suspension supply system; a pre-filling liquid supply system; and a control system, configured to control the pre-filling liquid system and the fibre suspension supply system to: at least partially fill the cavity with a pre-filling liquid from the pre-filling supply system to form a body of the pre-filling liquid in the cavity; and subsequently introduce a fibre suspension from the fibre suspension supply system to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.

2. The moulding system of claim 1, wherein the control system is configured to: at least partially fill the cavity with the pre-filling liquid during a first time period; introduce the fibre suspension into the at least partially filled cavity during a second time period; and remove liquid from the cavity during a third time period.

3. The moulding system of claim 2, wherein the second and third time periods overlap with each other and wherein the first time period does not overlap with the third time period.

4. The moulding system of any one of claims 1 to 3, wherein the mould comprises one or more of the following: an inlet into the cavity to receive the pre-filling liquid or the fibre suspension, and wherein the inlet is located above the cavity; a first inlet to receive the fibre suspension, wherein the first inlet is located above the cavity, and a second inlet to receive the pre-filling liquid, wherein the second inlet is located below the cavity.

5. The moulding system of claim 4, wherein the cavity has an elongate shape with a said inlet located at one longitudinal end of the elongate shape.

6. The moulding system of claim 5, wherein a major axis of the elongate shape of the cavity is vertically oriented.

7. The moulding system of any one of claims 1 to 6, further comprising a negative pressure source, and wherein the control system is configured to control the negative pressure source to apply a negative pressure to the exterior of the mould when controlling the fibre suspension system to introduce the fibre suspension to the at least partially filled cavity.

8. The moulding system of any one of claims 1 to 7, wherein the control system is configured to control the amount of fibre suspension introduced into the partially filed cavity using a flow rate of the fibre suspension into the partially filed cavity.

9. The moulding system of any one of claims 1 to 8, comprising a conduit network between the fibre suspension supply system and the cavity and between the pre-filling liquid supply system and the cavity, and wherein the control system is configured to control the pre-filling liquid supply system and the fibre suspension supply system to control the volume of pre-filing liquid in the cavity to be greater than a volume of air in the conduit network between the cavity and the fibre suspension system.

10. The moulding system of claim 9, wherein the fibre suspension supply system comprises a fibre suspension valve coupled to the conduit network and the pre-filling liquid system comprise a pre-filling liquid valve coupled to the conduit network, the moulding system comprising a drain conduit system coupled to an exterior of the mould and having a drain valve coupled between the exterior of the mould and a drain outlet; the control system configured to: open the pre-filling liquid valve to allow the pre-filling liquid supply system to at least partially fill the cavity with the pre-filling liquid; close the pre-filling liquid valve; and open the drain valve and open the fibre suspension valve to allow fibre suspension to be introduced into the cavity and liquid to be removed from the cavity.

11. A method of moulding a hollow moulded fibre product from a fibre suspension, the method comprising: at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity, the cavity being defined by one or more internal surfaces of the mould and the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; and subsequently introducing a fibre suspension to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.

12. The method of claim 11, comprising: at least partially filling the cavity with the pre-filling liquid during a first time period; introducing the fibre suspension into the at least partially filled cavity during a second time period; and removing liquid from the cavity during a third time period.

13. The method of claim 12, wherein the second and third time periods overlap with each other and wherein the first time period does not overlap with the third time period.

14. The method of any one of claims 11 to 13, wherein each of the pre-filling liquid and the fibre suspension are received into the cavity via one of the following: an inlet which is located above the cavity; a first inlet to receive the fibre suspension, wherein the first inlet is located above the cavity, and a second inlet to receive the pre-filling liquid, wherein the second inlet is located below the cavity.

15. The method of claim 14, wherein the cavity has an elongate shape with a said inlet located at one longitudinal end of the elongate shape.

16. The method of claim 15, wherein a major axis of the elongate shape of the cavity is vertically oriented.

17. The method of any one of claims 11 to 16, comprising using a flow rate of the fibre suspension into the partially filed cavity to control an amount of fibre suspension introduced into the partially filed cavity.

18. The method of any one of claims 11 to 17, comprising controlling the volume of pre-filling liquid in the cavity to be greater than a volume of air in a conduit network between the cavity and a fibre suspension system used to supply the fibre suspension for introducing into the cavity.

19. A control system configured to cause a moulding system to perform the method of any one of claims 11 to 18.

20. A non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a control system, cause the processor to control a moulding system to perform the method of any one of claims 11 to 18.

21. A receptacle manufacturing line comprising the moulding system of any one of claims 1 to 10 for moulding the hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle.

22. A method of manufacturing a receptacle, the method comprising performing the method of any one of claims 11 to 18 to mould the hollow moulded fibre product, and then performing at least one additional process on the hollow moulded fibre product to provide the receptacle.

23. A method of providing a content-containing receptacle, the method comprising providing a receptacle obtained by the method of claim 22 and providing the contents in the receptacle to provide the content-containing receptacle.

24. The method of claim 23, comprising: closing an opening of the receptacle after the providing contents in the receptacle, and/or applying a label or indicia to the receptacle.

25. Use of a receptacle obtained by the method of claim 23 to contain contents.