CN1144732C - Application of substances on a package - Google Patents

Abstract

The present invention relates to a process for producing a packaging system (4) comprising a first step, the packaging system comprising a hollow body (4), the first step consisting in applying a first substance onto a selected surface area of the packaging system by use of first application means (5), the selected surface area and the hollow body (4) being both in motion relative to the first application means (5) and the selected surface area being solely in contact with the first substance during the first step. The process also comprises a second step which consists in applying a second substance onto the selected surface area by use of second application means after completion of the first step, the selected surface area and the hollow body being both in motion relative to the second application means and the selected surface area being solely in contact with the second substance during the second step, the process taking place at a continuous line speed.

Description

Method of adding substances to packages

technical field

The invention relates to a method for producing packaging systems formed of hollow bodies on a production line.

Background of the invention

The method of producing packaging systems on a production line is widely used, especially in the consumer goods industry. Typically, such packaging systems are formed, printed, filled, and used to store and transfer items. In particular, the technique of applying substances to selected surface areas of such packaging systems is in most cases dedicated to printing on such packaging systems. There are many kinds of printing technologies available. The first printing technique used in industry involved printing large quantities of labels, which were stored on a large roll, which was then sent to a production line to glue the labels to the bottles. A second printing technique involves applying ink directly to the outer surface of the bottle, where the print can be customized to indicate, for example, the date of manufacture or a special reference number.

The invention relates to a method for producing a packaging system comprising first and second steps, the packaging system comprising a hollow body, the first step comprising adding a first substance to the packaging system using a first operating device On the selected surface, both the selected surface area and the hollow body are moved relative to the first operating means, the selected surface area being only in contact with the first substance in the first step. This method is known from the second printing technique mentioned above, where the printed matter is applied directly to the bottle, the printed letters and numbers usually being formed by a plurality of black dots.

The advantage of printing commercial information directly onto the bottles in motion relative to the handling device is that it is possible to produce bottles with mutually different information and to print at high speed on the production line. This method is especially suitable in the food and pharmaceutical industry, where the packaging preferably bears an identification number or a date of manufacture. Typically this commercial printing differs from the other prior printing methods of the first above in that the labels are pre-printed separately by a separate process and stored on cylinders before being glued to the bottles on the production line. In fact, in this method with a cylinder of printed labels, all labels are identical and any label will correspond to any bottle on the line. However, this method of using a cylinder for printing labels makes it possible to use labels with relatively high-definition images instead of letters or numbers formed by a limited number of dots of a single color.

Despite these and other advantages, existing methods, especially those that use rolls of printed labels or commercially printed dot matrixes on the production line, have disadvantages. For example, commercial methods of printing dot matrices produce poor clarity and are suitable for printing simple information in one color, such as dates, rather than printing high-resolution images or designs. Additionally, the method of printing labels on cylinders is not mobile and would require cylinders to be changed when label designs change, which would involve line stoppages or require a dual cylinder support system to change cylinders without production line stoppages. In any case, the use of printed label cylinders requires the storage of a variety of labels that meet the requirements, such as labels that are not directly produced on the production line.

It is common for a consumer product container to have high-quality printed images in the form of a logo design, along with information intended for consumers such as ingredients and/or directions for use. Typically, these images are printed on labels with pressure sensitive adhesive, which are then adhered to the container after the protective backing adhesive material has been removed. Accurately applying such labels to containers at high speeds is however difficult and may take a considerable amount of time due to tearing of the backing paper or pinching of the label. In addition, the labels must be printed separately, which again costs money and time. Label lamination and backing are also expensive and waste steam must be added. Space must be provided next to the plant and a list of storage labels must be established to ensure that the correct labels are applied to the appropriate containers.

Another disadvantage of using labels is that if the decorative graphics are changed, the remaining labels must be discarded and new labels printed. A new printing cylinder or plate is made from the time the new label is approved. It usually takes 4-6 weeks to print and transfer labels and prepare them for application.

Alternatively, screen printing techniques have been used to print images directly onto containers. But this technique is slower. Especially when printing multi-color images, it is slower and the quality of the images is limited. Typically only one to four colors are printed at any one time with screen printing, resulting in a limited complexity of the decorative image. If more colors are required, this can be done by passing the container multiple times through the printing station, but this will greatly increase the cost. Additionally, when using non-circular containers, such as ellipses or containers with complex curvilinear shapes, screen printing is slow, operating at rates as low as 50 containers per minute and as high as 100 containers per minute.

In addition, the stencils used in screen printing take a long time to manufacture, and such stencils are often replaced, which adds to the cost.

Thermal transfer technology has been used to print images directly onto containers. This technique is slow and has poor image quality. Additionally the pressure/heat applied by the conduction mechanism to the container to be printed may cause damage to the container, which is clearly undesirable. Additionally, the conduction process requires the use of conductive membranes, which is unnecessarily wasteful and increases cost.

It is known that high quality images can be obtained using digital printing techniques such as inkjet and laser techniques which are flexible in their application. Inkjet printing is typically used with water- or oil-based inks for printing on paper or other absorbent materials. The use of inkjet methods for circular and non-circular containers has been described in the prior art and has been described at speeds suitable for contemporary commercial production.

For example, Canadian Patent 1277176 discloses a method and apparatus for decorating containers of generally circular cross-section (circular or oval) using the ink jet method. This method relies on the relative movement of the container to be printed relative to the inkjet printhead, forming the overall image in a segmented manner. If the container is rotated about its longitudinal axis while moving it axially along that axis while the inkjet head remains stationary, or simply by rotating the container and moving the inkjet head in segments along the longitudinal axis of the container methods can be printed. Formation of the final image is therefore relatively slow. Also because the movement of the containers during printing is not through the inkjet head, this method is generally not suitable for printing large numbers of containers in a continuous manner to meet contemporary speed requirements. A similar technology is also disclosed in GB-2107 414 A.

US Patent No. 5,029,523 discloses a method and apparatus for printing graphics on the annular sidewall of a non-circular container. The apparatus includes a rather complex container handling mechanism consisting of a container carriage with an annular wall portion configured to match the side walls of the container which will pass over a roller between two rollers of adjacent inkjet heads The gap allows the side wall of the container to pass in front of the inkjet head at a constant distance.

This method and device is only suitable for printing tubular containers or containers having at least one opening in the dimension of the bottom, and not for printing bottles. In addition, printing large numbers of containers can only be done in a start-stop fashion, not continuously, because each container must make a full turn in front of the print head before moving forward, which then moves the other containers into print position . Consequently, this printing method is slow, typically less than 100 containers per minute, which is not suitable for printing the like of contemporary commercial bottles, which typically require 150-500 containers per minute.

The present invention seeks to provide a method of producing a packaging system of the type described above which provides both mobility and high rotational speeds when adding a substance to the packaging system and which is also operable over the wide speed range of industrial production.

Summary of the invention

According to the invention, this object is achieved by a method of the above-mentioned kind, wherein the second step comprises applying a second substance to a selected surface area by means of a second operating device after the completion of the first step, the selected Both the surface area and the hollow body are moved relative to the second attachment means, the selected surface area is only in contact with the second substance in a second step, the method is used at continuous line speed.

The method of the present invention has many advantages. Since it involves adding the first and second er' substances to the selected surface area while both the hollow body and the selected surface area are moving relative to the first or second means, it can be obtained directly Maneuverability of operations on the production line, and high clarity of application of individual substances to selected areas of the packaging system. Due to the improved maneuverability, the storage of labels such as high definition labels on the drum is greatly reduced, which reduces production costs. In addition, mobility reduces the waste of printed labels that are no longer used, thus benefiting the environment.

Detailed description of the invention

The method of the invention relates to a packaging system consisting of a container. In another embodiment, the packaging system is also associated with a container and a label for the container, which can be brought together or separated. In fact, according to the present invention, the packaging system can be processed in such a way that selected surface areas can be on the label, which are treated with the method of the invention prior to application to the container. When a substance is applied to a selected surface, according to the invention, the container moves even when no label is applied to the container. In fact both the container and the label are on a production line which is made to add the label after printing. Blank labels can also be applied to the container, and the substance can be applied to selected surface areas of the label when the label has been affixed to the container. In addition, it is also possible to dispense with a label, whereby the substance can be added directly to the container.

The invention also relates to a body, generally the hollow body is a container, such as a container for consumer goods. It is therefore preferred that the container is made of a material comprising a thermoplastic resin.

The first step of the method of the present invention involves applying a first substance, which is ink, to the selected area, preferably by inkjet technology. The selected area is on the packaging system and preferably covers at least 30 cm ² . Thus, the substance can be added to a label, to a container, to a lid or to a box. Adding the substance is done with the first attachment. Usually such means comprise the inkjet head of an inkjet printer, preferably an inkjet head with a plurality of nozzles.

According to the invention, both the selected surface area and the hollow body are moved relative to the first attachment means. This does not prevent selected surface areas and the hollow body from moving independently, allowing the label to be printed before being applied to the hollow body. However, what is meant here is that both components of the packaging system move on the production line. The relative movement may comprise a component consisting of movement of the first attachment itself. Especially when printing on a non-planar selected surface area, it is advantageous to move the handling device and the selected surface area. In any case, the hollow body is also moving so that, in the case of printing before the label is applied to the hollow body, the hollow body moves on the production line towards the place where the label is applied. In fact, in a preferred embodiment, the selected surface area is on the surface of the label which, after application of the substance, is secured to the support surface of the packaging system. This differs from the other preferred embodiment in that the selected surface area is an integral part of the outer surface of the hollow body.

The invention also mentions that selected surface areas are only in contact with the first substance in the first step. This means that there is no friction between any element and the selected surface area. It should be noted that the label itself can be in contact with the bottle if the selected surface area is on the label. In fact, the selected surface area refers to a two-dimensional surface. This friction over selected surface areas will occur in screen printing at a rate incompatible with the method of the present invention.

The second step of the present invention is similar to and follows the first step.

The method of the invention can be carried out at any modern production line speed which depends on the complexity of the inkjet technology used and the number of jets printing the same color. This is accomplished due to the continuous movement of the components of the packaging system and the absence of frictional forces applied to selected surface areas. In addition, multiple operating devices can also provide a boost in higher growth line speeds while achieving satisfactory operating results. The method is preferably used at a speed of at least 10 m/min, preferably at least 15 m/min, even at least 20 m/min, and optimally at least 28 m/min.

In a preferred embodiment, the method further comprises one or more additional steps comprising: applying an additional substance to a selected surface area with another operating device after the preceding steps have been completed, the selected Both the surface area and the hollow body are moved relative to the handling device, and in this additional step only selected surface areas are brought into contact with the additional substance. It should be appreciated that a different substance is preferably added in each additional step. A most preferred embodiment includes four additional steps, each of the six substances being a different ink, resulting in high definition images as well as high definition grayscale images with high contrast.

In a preferred embodiment of the invention, a method of printing an image on a selected surface area, such as on a non-planar container surface, includes moving a line of containers in a continuous fashion through a spray nozzle having a series of nozzles. Ink heads, the nozzles are separated in a direction perpendicular to the direction of movement of the container production line, and ink is ejected through these nozzles; when the above-mentioned containers pass the ink-jet heads, each container and/or the ink-jet heads are moved relative to each other, so that the jets The distance between the ink head and the surface of the container to be printed is kept substantially constant so that each part of the surface passes the inkjet head only once.

According to another preferred embodiment of the present invention, an apparatus for printing images on the surface of containers comprises a receptacle for each container, the receptacles are moved in a continuous manner through a conveyor of inkjet heads having a series of nozzles, the nozzles Ink is ejected through the nozzles perpendicular to the direction of movement of the receptacle; and means are also included for moving each container and/or the ink-jet head relative to each other as said container passes the ink-jet head so that during printing the surface of the container to be printed is aligned with the The distance between the inkjet heads is kept constant, and each part of the above-mentioned surface passes the inkjet heads only once.

The method and apparatus of embodiments of the present invention can print or decorate non-planar containers at a rate suitable for commercial production. For example, in a preferred embodiment of the invention, the method is capable of printing at least 150 containers per minute, preferably 300 containers per minute, and most preferably up to 500 containers per minute while obtaining high quality images and avoiding damage to the containers. container.

Another advantage of the present invention is that it is suitable for use with containers or labels of different shapes and/or different sizes, and for printing different graphics and/or contents.

Yet another advantage of the present invention is that it allows containers to be decorated at a lower cost than prior methods by eliminating labels and backing paper, transfer film or printing plates which are expensive to design and maintain.

It should be appreciated that containers having non-planar surfaces and having images printed on the surfaces can be obtained by employing the apparatus or method described above.

In a preferred method of the invention, the line of containers moves continuously past the inkjet heads. In this application, a production line of containers is intended to include a line of containers or other designs in which multiple containers are passed consecutively through an inkjet head. During printing, the container can be placed vertically or horizontally, although it is best to place it vertically.

Also, when a line of containers moves continuously, here it means that there is a continuation between printing this one and the next container on the line, unless a change of method is required or the printing unit needs to be serviced, the container line will be kept on a non-stop basis move.

During printing, a small and substantially constant distance is maintained between the container to be printed and the inkjet head, otherwise, the position and size of ink dots produced on the surface of the container will vary, and on the printed part of the surface, Some places cause the image to be blurry, others are too light, or it can cause damage to the inkjet head or container.

Usually, before printing, the distance between the printed surface and the inkjet head is set to a predetermined value. Usually, the distance is kept at 0.2-4mm, preferably 0.5-2.5mm. If the distance is large, the airflow may affect the inkjet nozzle. ink, resulting in poor image quality. This is what the essentially constant distance means in this application. This distance is preferably kept constant at 1mm or 0.5mm.

The predetermined distance is maintained by moving the container to be printed and/or the inkjet head. For example, the inkjet head can be moved to follow the shape of the container to be printed. However, for simplicity, the inkjet heads may be kept stationary and each container moved relative to them. In this case, preferably prior to printing, each container is positioned such that the front or edge of each container to be printed is at a predetermined distance from the ink jet head in the direction of travel of the container line. The container is then gradually moved or rotated about its longitudinal axis so that as the container surface moves past the inkjet head, each portion of it turns a predetermined distance away from the inkjet head, up to the rear of the container surface. The portion or edge turns to a predetermined distance away from the inkjet head. When the container to be printed has a complex shape, it may be necessary to reverse the direction of rotation of the container as it passes the inkjet head. Preferably, of course, each part of each container to be printed passes the inkjet head only once at the entire process speed.

The direction and angle of rotation that is employed first will depend on the shape of the container to be printed and the shape of the curve that will follow. For example, if the container moves substantially in a straight line and has a surface that is convex toward the head, the front of the surface must first move toward the head and then gradually move away from the head until the head reaches the apex or turning point of the surface , then the rear edge of the surface must gradually move towards the inkjet head.

If the container moves in a curve, the container must rotate either towards or away from the inkjet head, depending on the movement curve and the corresponding radius of curvature of the container surface. Usually the radius of curvature of the container is smaller than the curve, which requires movement as described above. However, if the radius of curvature of the container is greater than the radius of curvature of the curve, the front edge of the container can be gradually moved away from the inkjet head until the inkjet head reaches the top of the curved surface, and then the rear edge of the container can be moved to gradually approach the inkjet head .

During printing, the frequency of ink droplets ejected from the inkjet head must be adjustable to compensate for small variations in the linear velocity of the container surface across the inkjet head. The jetting time must also be adjustable to compensate because most inkjet heads are not perpendicular to the container surface during printing. However such modifications are within the expertise of professionals.

There are a number of ways to move the container in the desired manner relative to the inkjet head. For example simple servo motors or a cam mechanism can be used. If an electric motor is used, it will usually be controlled by a computer program specific to the shape and size of the container to be printed, so that it can be used to print different containers by simply changing the program. This may therefore prove to be more convenient than using a cam mechanism.

If desired, the present invention may use at least one sensor to monitor the distance between the container surface and the inkjet head. Any suitable sensor may be used, such as infrared sensors, laser sensors, acoustic proximity sensors, and the like. The sensor is connected to a device that moves the inkjet head and/or the container relative to each other, adjusting if necessary during the printing process, or after changing from printing one type of container to another of a different shape and/or size Movement of mobile devices.

During printing, each container is preferably secured in a receptacle on a conveyor belt or carousel. In this case, each container can be moved relative to the inkjet head by moving the corresponding receptacle. Each receptacle preferably includes means for securing its container so that there is substantially no relative movement between the container and its receptacle during printing operations. Typically the fixture contacts the container at least at one point on its top and bottom. Any suitable fixing means may be used, for example an angled stop may be inserted into the top of the container to fit snugly and to secure the bottom of the container to an angled receptacle having substantially the same shape as the bottom. The features of the fixture preferably allow the receptacle to be used for containers of different sizes and/or shapes and to be easily applied to these containers so that it can be changed from one production line to another in a very short amount of time. It reflects the great superiority of contemporary commercial production.

Depending on the complexity of the image to be printed and/or the number of container surfaces, the method of the invention may employ one or more inkjet heads. Each inkjet head comprises a series of nozzles arranged in a direction perpendicular to the direction of the production line or the rows of containers to be printed. Ink can be ejected from the nozzles in a continuous fashion or drop-by-drop on command under digital control as described in the literature. The ink is preferably ejected drop by drop from the nozzle on command.

Since the container surface is simply passed by each inkjet head, the number of nozzles and the width of their array will be chosen according to the image to be printed. Each inkjet head will typically have at least 7/mm. Preferably at least 12 nozzles/mm, which may be arranged in one or more parallel lines, the inkjet head will preferably be capable of printing at least 200 dots per inch in the longitudinal direction through which the container passes, preferably 360 dots per inch point.

It is best to use multiple gray levels to get high quality images and small text font quality. It is best to use at least 4 gray levels. Examples of inkjet heads capable of this print quality are the Xaar Jet 1000 or Xaar Jet 1000S supplied by Xaar.

When multiple inkjet heads are used to print inks of different colors, also including black and white inks, it is essential that they be positioned so as to obtain good color-to-color image registration on the final printed container. Usually the required image overlap is: the positioning error of different color points is 100-400μ, preferably less than 200μ, preferably less than or equal to 70μ.

For a combination of dense black, good text fonts, and fine, realistic graphics. The method of the present invention can be combined with some special printing techniques. For example, for maximum flexibility and high-quality printing, it is best to use so-called "Hi-Fi" color printing using 6-7 colors, which can use cyan, magenta, yellow and black plus any of the following: One: i) green or orange, or ii) red, green and blue. Doing so expands the available color space, enables high-quality decoration at a lower cost, and avoids the need for a large number of specialized colors to produce dense colors in conventional printed container images.

When it is necessary to print on more than one part of the container surface, for example on diametrically opposite surface parts or on opposite sides of the container, after each container has passed the first inkjet head, it The axis is then rotated by at least 90[deg.], presenting the next container surface or side to be printed in front of the other print head. For example, if the opposite side of the container is to be printed, simply rotate the container about 180° on the inkjet head or array of inkjet heads, then print the second surface portion or side, and then turn the container and/or inkjet head Moving in the above-mentioned manner, thereby keeping the distance between the container surface and the ink-jet head substantially constant.

Any ink can be used for printing, although some inks are preferred depending on the material from which the container is to be printed. For example, for those non-absorbent containers, such as plastic, metal and glass containers, it is best to use phase change inks, such as hot-melt inks, hot-melt solvent-free toner inks or radiation-curable inks, usually It is UV curable ink. In this case, if there are several inkjet heads, it is advantageous to provide means for melting or curing the ink after each inkjet head and/or at the end of the entire printing job. Regardless of the type of ink used, the surface of the container should have a high enough surface energy to allow the ink to stick. This can be done by flame treating the plastic container and methods known in the prior art.

Radiation-curable inks are preferably inks that require heat to dry, and their use appears to cause little damage to containers. UV-curable inks are particularly preferred because they bond easily to plastic surfaces and are durable durable. The use of such inks has been described in the prior art of inkjet technology.

The present invention is suitable for printing containers of various sizes and/or shapes, and is most suitable for printing containers with curved or non-planar surfaces. It is especially suitable for printing surfaces that are only curved in a certain sense or direction, such as concave or convex surfaces, such as opposing surfaces that contain both convex and concave parts. Specific examples include bottles with circular or oval cross-sections.

The invention is also suitable for printing containers made of various materials, such as paperboard, cardboard, plastic, glass and metal containers. However, the main purpose of the present invention is to be used for printing lighter plastic containers, used plastics usually include polyethylene, polypropylene, nylon, polyester or polyvinyl alcohol used in laundry detergent, cosmetics, beauty containers, and food industries, and also For printing labels. Products in these industries often require timely improvements on the basis of standards, and can quickly respond to market changes or competitors' activities. The basic requirement is to quickly print containers, and the printing method requirements are easily applicable to production lines of different products. . The present invention satisfies the above two requirements, namely the time requirement and the high speed similar to the filling speed.

Now see attached image:

Fig. 1 is a plan view looking down from the top of the printing device of the present invention,

FIG. 2 is an enlarged, orthogonal view of a station of FIG. 1 incorporating an embodiment of a container receptacle moving device.

Referring to FIG. 1 , the apparatus 1 comprises a carousel 2 with a plurality of receptacles 3 holding bottles 4 passing through a series of inkjet heads 5 . Each receptacle includes securing means (not shown) for securing a respective bottle contained therein.

Each receptacle is movable on a carousel such that a small, substantially constant distance is maintained between the surface of the bottle to be printed and the corresponding inkjet head. In order to cure the ink printed on the bottle, a UV lamp 6 is installed after each inkjet head, and if necessary, another UV lamp 7 is installed behind the subsequent inkjet head, so as to ensure that the printed ink is completely cured. As an alternative to UV lamps, fiber optics can be used to transmit UV light from distant light sources, thereby saving space.

Individual bottles 4 from a dispenser 9 of conventional type are placed in their respective receptacles 3 by a conveyor belt 8 . While the bottles are in the conveyor belt 8, they may be subjected to other treatments, such as a lamp processor 10, which act to reduce surface tension and promote ink adhesion. In addition, a 180° rotating station 11 is provided to feed the other side of the printed container to the subsequent inkjet head.

After printing, the bottles leave the carousel and video equipment 12 is used to monitor the print quality.

Referring now to Figure 2, a bottle 21 is secured to a beveled disc 22, and a beveled stopper 23 is suspended from a bracket 24 and inserted into the top of the bottle. The pucks are supported on a carousel 25 (partially shown) which carries the bottles past the inkjet heads 26 . Below the carousel, a motor 27 turns a shaft 28 attached to the disc, thereby turning the bottles in front of the inkjet head. The motor rotates the bottle under program control, so that the distance between the surface of the bottle to be printed and the inkjet head is usually kept below 2mm.

Claims (10)

1. A method for producing a packaging system comprising first and second steps, (a) the packaging system comprising a hollow body, (b) the first step comprising applying a first manipulation device to a selected surface of the packaging system The first substance is applied to the area, the selected surface area is moved relative to the first operating means, and the selected surface area is only in contact with the first substance but not with the first operating means during the first step, (c ) a second step comprising applying a second substance to a selected surface area using a second operating device after completion of the first step, the selected surface area being moved relative to the second operating device, and during the second step, The selected surface area is only in contact with the second substance, but not with the second operating device; The method is characterized in that during the first step the hollow body is moved relative to the first operating means without friction between the selected surface and the first operating means, during the second step the hollow body is moved relative to the second The manipulator moves without friction between the selected surface and the second manipulator, and the method is used at continuous line speed. 2. The method of claim 1, wherein the method further comprises one or more additional steps comprising applying additional substances to selected surface areas using additional operating means after the previous steps have been completed, Both the selected surface area and the hollow body are moved relative to the additional manipulation means, the selected surface area being in contact with the additional substance but not the additional manipulation means in an additional step. 3. The method of claim 2, wherein the additional step follows the second step so that the addition of six substances occurs. 4. The method of claim 1, wherein the first and second substances are inks. 5. The method of claim 1, wherein the hollow body is a bottle or cap made of a material comprising a thermoplastic resin. 6. The method of claim 1, wherein the selected surface area is on the surface of the label, the label being secured to the support of the packaging system after the substance is applied. 7. The method of claim 1, wherein the selected surface area is an integral part of the outer surface of the hollow body. 8. The method of claim 1, wherein the selected surface area covers at least 30 ^cm2 . 9. The method of claim 1, wherein the operating device is an inkjet printer. 10. The method of claim 1, wherein the selected surface area is not a plane.