GB2392408A

GB2392408A - Improvements in or relating to moulding

Info

Publication number: GB2392408A
Application number: GB0220033A
Authority: GB
Inventors: Martin Waller
Original assignee: VERNA Ltd
Current assignee: VERNA Ltd
Priority date: 2002-08-29
Filing date: 2002-08-29
Publication date: 2004-03-03
Also published as: AU2003260735A1; WO2004020739A1; GB0220033D0

Abstract

A retaining pin (30) for a hollow molded article, such as a male urine bottle (A) moulded from paper pulp and having a neck portion (N) (figure 5-not shown) with an entrance aperture, has a portion (44) which engages with the inner surface of the neck portion (N) of the article in the vicinity of the aperture. When the moulded article is placed on the pin (30) it still contains a lot of water and is thus pliable and by virtue of its weight it is pressed into engagement with portion 44. The portion (44) thus engages with the inner surface of the article near the aperture and forms a smooth inner surface on the article, making it more comfortable to use. A projection 40 of the pin 30 has a surface 42 to engage a portion of the article. The pins 30 are mounted on an endless chain 26 which is moved through a drying oven. The article is dispensed from a mould 20 onto the pin 30.

Description

- DESCRIPTION

IMPROVEMENTS IN OR RELATING TO MOULDING

The present invention relates to moulding and in particular, but not exclusively, to the moulding of hollow articles from a paper pulp slurry.

It is known to make hollow articles such as urine bottles and the like from a paper pulp slurry. Such articles are designed to be disposable in a macerator and greatly reduce the risk of cross-infection in hospitals, nursing homes and the like.

Such articles are produced either by pressure moulding or, more preferably, by vacuum moulding. In either case, a hollow mould is immersed into a tank full of paper pulp slurry and either pressure or vacuum is applied to deposit paper pulp fibres onto a porous moulding surface and to extract water from the deposited pulp.

After withdrawing the mould from the vat of paper pulp slurry, pressure or vacuum, as appropriate, is applied in order to extract more water from the moulded product. The mould is then manoeuvred to a position where an article retaining pin is inserted into the neck of the moulded article, whereupon the mould is opened to deposit the moulded article on the retaining pin. The retaining pin together with the moulded article carried by it, is then moved through a drying oven where the moisture content of the moulded article is reduced still further to the desired value.

For health care products such as urine bottle, it is important for the internal surface wall of the moulded article in the vicinity of the entrance aperture to be relatively smooth to make is comfortable to use, so as not to deter users of the product. However, since the paper pulp slurry enters the mould via the entrance aperture and since excess paper pulp slurry flows out of the aperture when the mould

is withdrawn from the vat of paper pulp slurry, the internal surface of the article in the vicinity of the entrance aperture tends to be relatively rough.

It is an object of the present invention to overcome or alleviate the problems associated with the prior art.

In accordance with a first aspect of the present invention, there is provided a retaining pin for a hollow moulded article having a neck portion with an entrance aperture, comprising an article moulding portion for engagement with a portion of the inner surface of the article in the vicinity of the aperture.

When a hollow moulded article is dispensed from the mould, its water content is still relatively high (of the order of 80% water). Thus, although the article will generally retain its shape if handled carefully, it is sufficiently pliable for it to be further moulded. By providing the pin with a moulding portion which abuts a portion of the inner surface of the moulded article, it is possible to form a smooth inner wall portion in the vicinity of the aperture of the article Preferably, the article moulding portion is situated at or towards the base of the pin. Preferably, the article moulding portion is smooth. In one embodiment it is frusto-conical. The pin may further comprise one or more sure; for cI;,cll. WILll a further portion of the article, e.g. a surface at or towards the upper end of the pin for engagement with an inner wall of the hollow article and/or a surface located above the article moulding portion for engagement with the neck portion of the article.

the present invention also includes a transport apparatus comprising a plurality of retaining pins in accordance with the present invention.

: The retaining pins are preferably mounted on a moving conveyor means (e. g. an endless chain conveyor) which is preferably moved stepwise.

The present invention also includes an apparatus for moulding hollow articles, which incorporates a transport apparatus in accordance with the present invention.

By way of example only, a specific embodiment of the present invention will now be described, with reference to the accompanying drawings, in which: Fig. l is a perspective view of a known moulding apparatus; Fig. 2 is a perspective view of an example of male urine bottle which may be moulded with the apparatus of Fig. 1; Fig. 3 is a perspective view from the front and one side of a pin for receiving a moulded article, in accordance with the present invention; Fig. 4 is a perspective view from the rear and the other side of Fig. 3; and Fig. 5 is a perspective view of the article of Fig. 2 in position on the pin of fig. 3. Fig. l of the enclosed drawings illustrates in general terms an apparatus for vacuum forming hollow articles as described in GB-A-2153740B. In general terms, the apparatus comprises a tank l O for holding a slurry 12 of paper pulp. A mould transport apparatus 14 is mounted for pivotal movement about an axis 16 by means of a hydraulic ram 18 which controls the pivotal movement of the transport apparatus in an oscillatory manner between first and second positions as will be described. A plurality of banks of two-piece moulds 20 are carried by the transport apparatus (although only one bank of moulds is illustrated in Fig. 1). Means is provided for applying suction to the moulds as the open ends of the moulds are indexed stepwise

into the paper pulp slurry. This causes paper pulp to be deposited on the moulding surface of the moulds and as the moulds are indexed stepwise out of the slurry the suction is applied to withdraw additional water from the material deposited within the moulds.

Eventually, each bank of moulds reaches a conveyor apparatus 22 in the form of a series of banks of upstanding pins 24, one pin being provided for each mould.

The pins are mounted on an endless chain conveyor 26 which is indexed stepwise, the movement being synchronised with the pivotal movement and opening of the moulds such that the hydraulic ram 18 is actuated to move the mould transport apparatus 14 downwards so that each of the pins in the bank of moulds is received within the aperture of a hollow article A deposited on the moulding surface of a mould. The mould is then arranged to open which deposits the moulded article on its associated pin. The mould transport apparatus 14 is then pivoted upwardly by means of the hydraulic ram 18 and are then indexed stepwise. This operation is repeated indefinitely.

The endless chain 26 on which the pins are mounted is moved through a drying oven which reduces the moisture content of the moulded article to the desired level. Such apparatus is known from, for example, GB 2153740A. However, the article retaining pins as illustrated in Figs. 3 to 5 are different from those described in the known arrangements.

As shown in Figs. 3 to 5, each of the pins 30 is in the form of a generally elongate hollow member having a smooth, generally planar front face 32 (i.e. facing in the forward direction of travel when the pin is upright) and two smooth, generally

planar side faces 34, 36. The rear face 36 is also smooth and generally planar but the upper portion of the rear face is provided with an inclined face 3 8 in order to engage the base wall of the moulded article A over a relatively large surface area, in order to minimise the likelihood ofthe pin deforming or damaging the base wall of the article.

The rear face of the pin is also provided with a projection 40 lower down having a smooth face 42 to engage a neck portion of the article. The shape and position of the inclined portions and projections will vary, depending upon the nature and shape of the article to be moulded. The pin 30 is mounted on a base B by means of which it is secured, in use, to the chain conveyor 26.

However, it will also be observed that the base of the pin is formed into a frusto-conical shoulder 44. The shoulder 44 is shaped to engage with the inner surface wall of the neck of the moulded article. As stated previously, when the article is dispensed from the mould onto the pin, its water content is still very high such that the article itself is pliable. As the article is displaced onto the pin, the inner wall of the neck portion N abuts the frusto-conical shoulder 44 and by virtue of the weight of the moulded article (which is significant, in view of the high water content) the inner frusto-conical face of the neck of the article is pressed into engagement with the frusto-conical shoulder. Since the moulded article is still in a pliable condition at this stage, the frustoconical inner wall of the neck portion of the moulded article is given a smooth finish which corresponds to the smooth surface of the frustoconical shoulder. In this way, the inner wall of the moulded article immediately adjacent to the opening is given a smooth finish which is important for acceptability by users and for

reasons of comfort during use.

The invention is not restricted to the details of the foregoing embodiment.

For example, the shape and/or location of the moulding portion of the pin may differ from those described, depending upon the shape, size and nature of the article to be moulded.

Claims

1. A retaining pin for a hollow moulded article having a neck portion with an entrance aperture, comprising an article moulding portion for engagement with a portion of the inner surface of the article in the vicinity of the aperture.

2. A retaining pin as claimed in claim I, wherein the article moulding portion is situated at or towards the base of the pin.

3. A retaining pin as claimed in claim 1 or claim 2, wherein the article moulding portion is smooth.

4. A retaining pin as claimed in claim 3, wherein the article moulding portion is frusto-conical.

5. A retaining pin as claimed in any of the preceding claims, further comprising one or more surfaces for engagement with a further portion of the article.

6. A retaining pin as claimed in claim 5, comprising a surface at or towards the upper end for engagement with an inner wall of the hollow article.

7. A retaining pin as claimed in claim 5 or claim 6, comprising a surface located above the article moulding portion for engagement with the neck portion of the article.

8. A retaining pin for a hollow moulded article, substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

9. A transport apparatus comprising a plurality of retaining pins as claimed in any of the preceding claims.

10. A transport apparatus as claimed in claim 8, wherein the retaining pins are mounted on a moving conveyor means.

I I. A transport apparatus as claimed in claim 9, wherein the conveyor means is moved stepwise.

12. A transport apparatus substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

13. An apparatus for moulding hollow articles, comprising a transport apparatus as claimed in claim 8.

14. An apparatus for moulding hollow articles substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

Amendments to the claims have been filed as follows q 1. A retaining pin for receipt of a hollow moulded article from a mould, the hollow moulded article having a neck portion with an entrance aperture, the pin comprising an article moulding portion for engagement with a portion of the inner 5surface of the article in the vicinity of the aperture.

2. A retaining pin as claimed in claim 1, wherein the article moulding portion is situated at or towards the base of the pin.

104. A retaining pin as claimed in claim 3, wherein the article moulding portion is frusto-conical.

S. A retaining pin as claimed in any of the preceding claims, further comprising one or more surfaces for engagement with a further portion of the article.

6. A retaining pin as claimed in claim 5, comprising a surface at or towards 15the upper end for engagement with an inner wall of the hollow article.

8. A retaining pin as claimed in any of the preceding claims, wherein the pin 20is mounted at its base.

9. A retaining pin for a hollow moulded article, substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

1 10. A transport apparatus comprising a plurality of retaining pins as claimed in any of the preceding claims.

l 1. A transport apparatus as claimed in claim 10, wherein the retaining pins 5 are mounted on a moving conveyor means.

12. A transport apparatus as claimed in claim l 1, wherein the conveyor means is moved stepwise.

13. A transport apparatus as claimed in any of claims 1 0 to 1 2, wherein the retaining pins are each mounted at their base.

10 14. A transport apparatus substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

15. An apparatus for moulding hollow articles, comprising a transport apparatus as claimed in any of claims 10 to 14.

16. A method of removing a hollow moulded article from a mould, 15 comprising discharging the article from the mould onto a retaining pin while the article is still mouldable and causing a portion of the inner surface of the article to contact and conform to the shape of a portion of the retaining pin.

17. A method as claimed in claim 16, wherein the pin comprises a pin as claimed in any of claims 1 to 9.

20 18. A method of removing a hollow moulded article from a mould substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

1\ 19. A method of forming a hollow moulded article, comprising forming the article in a mould, discharging the article from the mould onto a retaining pin while the article is still mouldable and causing a portion of the inner surface of the article to contact and conform to the shape of a portion of the retaining pin.

5 20. A method as claimed in claim 19, further comprising the step of hardening the article into a non-mouldable state.

21. A method as claimed in claim 20, wherein the step of hardening the article into a non-mouldable state comprises drying the article whilst in position on the retaining pin.

10 22. A method as claimed in claim 20 or claim 21, further comprising the step of removing the hollow moulded article from the retaining pin.

23. A method as claimed in any of claims 19 to 22, wherein the article to be moulded comprises a neck portion and wherein a portion of the inner surface of the neck portion contacts and conforms to the shape of a portion of the retaining pin 15 when still mouldable.

24. A method as claimed in any of claims 16 to 23, wherein the pin comprises a pin as claimed in any of claims 1 to 9.

25. A method as claimed in any of the preceding claims, wherein the article comprises hollow paper pulp formed in the mould from a paper pulp slurry.

20 26. A method of forming a hollow moulded article substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

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