Technique for breaking out stamping slugs

Abstract

Method for breaking out a stamped slug from a product (200), comprising: - Punching a slug (260) at a desired position in the product (200), wherein the punched slug (260) remains connected to the product (200) after the punching process by at least one holding point (200a, 200b) or holding film; - Creating a depression (262) in the area of ​​the die-cutting slug (260), wherein the step of creating the depression (262) and the step of die-cutting the slug are carried out simultaneously, or the step of creating the depression (262) is carried out before the step of die-cutting the slug (260); and - Breaking out the punched slug (260) by means of a breaking tool, wherein the produced recess (262) is dimensioned such that during breaking out the breaking tool or a part thereof comes into engagement with the recess (262).

Description

TECHNICAL AREA

[0001] The present invention relates to a method and a device for breaking out a stamped slug from a product. Furthermore, the present invention relates to a thermoforming machine with a thermoforming tool for forming a product and the device for breaking out a stamped slug from the product. STATE OF THE ART

[0002] In the packaging industry, die-cutting is a common practice used to create small cutouts or holes in packaging (such as cups or other containers). These small cutouts or holes can be used, for example, to hang the packaging on shelves or as a spout / drinking hole. The packaging can be made of plastic or other materials, such as sheet metal. Thermoforming is frequently used as a manufacturing process for plastic packaging.

[0003] The terms "slug" or "die-cut slug" (both terms are used synonymously below) refer to small pieces of waste material that remain attached to the packaging after die-cutting via at least one retention point or adhesive strip. A retention strip is a slightly wider connecting ridge than a retention point that links the die-cut slug to the packaging after the die-cutting process. Using a stripping tool, the die-cut waste material (or slug) is removed from the packaging by cutting through the at least one retention point or adhesive strip. This leaves the desired hole in the packaging. Fig. Figure 1 shows an example of such packaging. Specifically, in Fig. Figure 1 shows a beaker 10 with a sealing rim 12, wherein a hole 14 is formed at a desired location on the sealing rim 12. The hole 14 is produced by punching out and breaking out the boss 16.

[0004] Packaging production is generally highly automated. For plastic packaging, such as plastic cups, thermoforming machines with corresponding thermoforming tools are preferably used to form cups from plastic film. Such thermoforming tools for forming cups are described, for example, in DE 10 2016 103 237 A1 and DE 33 14 864 A1. The thermoforming tool in DE 33 14 864 A1 is also designed to punch larger openings in the base of the formed plastic cups.

[0005] The die-cutting and subsequent removal of the individual pieces is also automated. One problem with the automated removal of the individual pieces is that they don't always detach from the packaging. Such a situation occurs in the Fig. 2a-2d shown. Fig. Figures 2a-2d show a section of a package 100 with a die-cut 160. Fig. Figure 2a shows a top view of packaging 100, while the Fig. Figures 2b-2d show a side view along line AA of the packaging 100. After the die-cutting process, the slug 160 is connected to the packaging 100 via two holding points 100a, 100b ( Fig. 2a) In a subsequent breaking process, the slug 160 is broken out using a breaking tool (for example, a breaking plunger). The breaking plunger (hereinafter referred to as plunger) is not shown in the figures. In the Fig. Figures 2b-2d merely illustrate the movement of the plunger relative to the punched-out slug 160 with an arrow 20. It is possible that when the plunger impacts the punched slug 160, only one retaining point 100a is severed, and the slug 160 remains connected to the packaging 100 via the other retaining point 100b. As a result of this one-sided severance, the slug 160 tilts sideways downwards (hinge effect -> see [reference]). Fig. 2c and Fig. 2d). One consequence of this lateral tilting of the slug 160 is that the plunger slides past the slug 160 without completely breaking it out. The slug 160 thus remains stuck to the packaging 100 ( Fig. 2d).

[0006] From DE 20 2010 017 955 U1 a technique for breaking out a waste part from a sheet is known, wherein the waste part has a recess and a breaking-out tool is used which has an insert element that engages in the recess of the waste part to be broken out.

[0007] Furthermore, EP 1 679 163 A1 discloses a stripping technique in which a stripping tool is provided with stripping elements designed for stripping a blank from a sheet. The blank to be stripped rests on a flexible counter-support; to overcome the flexible support, the blank is slightly bent downwards with the aid of the stripping tool, thereby enabling a reliable separation of the blank from the sheet.

[0008] Furthermore, a stripping tool is known from DE 10 2107 105 508 A1, which has stripping pins and stripping strips designed to press a flat workpiece downwards in order to strip it from a sheet.

[0009] The object of the present invention is to provide a technique that enables the reliable removal of die-cut slugs. Furthermore, the technique should be implementable / integrable into conventional packaging manufacturing processes, such as conventional thermoforming processes. BRIEF SUMMARY

[0010] To solve the above-mentioned problem (as well as other problems), a method for removing a stamped slug from a product is provided according to a first aspect, the method comprising the following steps: stamping a slug at a desired position in the product, wherein the stamped slug remains connected to the product after the stamping process by at least one holding point or holding film; creating a depression in the area of ​​the stamped slug, wherein the step of creating the depression and the step of stamping the slug are carried out substantially simultaneously or the step of creating the depression is carried out before the step of stamping the slug; and removing the stamped slug by means of a stripping tool, wherein the created depression is dimensioned such that, during stripping, the stripping tool or a part thereof engages with the depression.

[0011] In the following, "product" refers to a packaging product, such as a cup or a lid. The packaging product can be made of plastic or another malleable material, such as sheet metal. If the product is made of plastic, it can be manufactured by thermoforming a plastic film. Such a packaging product is also referred to below as a thermoformed product.

[0012] The steps of punching the slug and creating a depression in the slug (or on the surface of the slug) are performed according to a predetermined sequence. In one variant, the depression creation step is performed before the slug punching step. In this case, the slug is punched at the position on the packaging (or packaging surface) where the depression was created. In an alternative variant, the slug punching and depression creation steps are performed essentially simultaneously. In both variant processes, the punched slug includes the created depression.

[0013] The stripping tool can be dimensioned such that it can engage in the created depression. According to one implementation, the stripping tool can include a stripping plunger (or ram) dimensioned to engage in the depression created in the slug. In other words, the depression and the stripping tool (or the plunger of the stripping tool) can be dimensioned such that the stripping tool (or the plunger) can engage in the depression during the stripping process.

[0014] According to one implementation, the product can be a thermoformed product, formed by thermoforming a plastic film using a thermoforming tool (a thermoforming machine). The indentation can be created (thermoformed) using the thermoforming tool. For example, the indentation can be created by applying compressed air or a vacuum and / or by using a ram (pre-stretcher) in the area of ​​the die. The indentation of the die can thus be created simultaneously with the thermoforming of the product.

[0015] Alternatively, the indentation can be embossed onto the surface of the die using an embossing tool. If the product is a thermoformed product, which is formed by thermoforming a plastic film using a thermoforming tool, the embossing tool for imprinting the indentation can be integrated into the thermoforming tool (or forming station) of the thermoforming machine.

[0016] The punching step of the slug can be performed using a punching tool. The punching tool can be designed in the form of a (ring-shaped) punching line. This line can have at least one indentation to create at least one holding point or holding film. The punching tool can be part of the thermoforming tool (or forming station) of the thermoforming machine. Integrating the punching tool into the thermoforming tool (or forming station) can further accelerate product manufacturing. Alternatively, a separate punching tool can be provided, which punches the product after it leaves the thermoforming tool (or forming station) of the thermoforming machine.A stamping tool designed separately from the thermoforming tool for stamping the slug can be housed in a stamping station of the thermoforming machine, which is intended for stamping out the thermoformed product.

[0017] Furthermore, the stamped slug can be stripped using a stripping tool located in the thermoforming machine. For example, the stripping tool can be housed in a (separate) stripping station of the thermoforming machine. Alternatively, it is also conceivable that the stripping tool is integrated into the thermoforming tool (i.e., in the forming station) or into the stripping station of the thermoforming machine. In all implementation variants mentioned here, the stripping tool can include a ram designed for stripping the slug.

[0018] According to a further aspect of the invention, a device for breaking out a stamped slug from a product is provided. The device comprises a stamping tool designed for stamping a slug at a desired position in the product; a forming tool designed for producing a depression on the surface of the stamped slug, wherein the forming tool and the stamping tool are designed to perform the production of the depression in the slug and the stamping of the slug substantially simultaneously, or to produce the depression in the slug prior to stamping the slug; and a stripping tool designed for breaking out the stamped slug, wherein the stripping tool is dimensioned such that, during stripping, the stripping tool, or a part thereof, engages with the depression of the slug.

[0019] The forming tool for creating the indentation can be a tool designed for thermoforming the indentation. This forming tool can include a mold chamber that replicates the indentation of the slug, into which the plastic film to be formed is pressed using compressed air or a vacuum and / or a ram (pre-stretcher). The forming tool can, for example, be part of a thermoforming tool for manufacturing a thermoformed product. In other words, the forming tool for creating the indentation can be integrated into the thermoforming tool. The indentation for the die-cut slug is thus created (formed) by the thermoforming tool (tool base and / or tool top) in a similar way to the product itself.

[0020] Alternatively, the forming tool for creating the indentation can be an embossing tool. The embossing tool can be designed to imprint the indentation on the surface of the die. The embossing tool can be housed within the thermoforming tool of a thermoforming machine.

[0021] According to another aspect, a thermoforming machine is provided for thermoforming a product. The thermoforming machine includes a thermoforming tool designed for shaping the product. Furthermore, the thermoforming machine includes the aforementioned device for creating and breaking out a stamped slug in the product.

[0022] The forming tool of the aforementioned device can be housed within the thermoforming tool of the thermoforming machine. The punching tool of the device can likewise be located within the thermoforming tool of the thermoforming machine or in a punching station of the thermoforming machine downstream of the thermoforming tool. The stripping tool (stripping ram) of the device can be located within the thermoforming tool (i.e., in the forming station of the thermoforming machine), in the punching station of the thermoforming machine, or in a separate stripping station of the thermoforming machine.

[0023] The thermoforming tool can comprise a lower tool section and an upper tool section that interacts with the lower tool section, as described above. The upper tool section can be movable relative to the lower tool section. Alternatively, the lower tool section can be movable relative to the upper tool section. The lower tool section can include a forming device for shaping the product and for forming the recess at a suitable location on the product. The upper tool section can include a pre-stretcher for pre-stretching the plastic film inserted between the lower and upper tool sections. BRIEF DESCRIPTION OF THE FIGURES

[0024] Further details and advantages of the invention are explained in more detail with reference to the drawings. They show: Fig. 1. A product with an additional cutout; Fig. 2a to 2d schematic representations illustrating the breaking out of a lump according to the state of the art; Fig. 3 a flowchart illustrating a method for breaking out stamping slugs according to the present invention; and Fig. 4a to 4d schematic representations illustrating the effect of the in connection with Fig. 3 further illustrate the inventive method described. DETAILED DESCRIPTION

[0025] The Fig. 1 and 2a-2d were discussed above in connection with the state of the art.

[0026] Based on Fig. Section 3 now describes in more detail a method according to the invention for breaking out punched slugs from a product. The product can, for example, be a thermoformed product produced by thermoforming a plastic film. Such a product can be conventional packaging, such as a cup. A hole is punched out at a predefined location on the product.

[0027] In step S10, a depression 262 is first created at a desired (predefined) position on the surface of the product 200. This depression 262 is part of a slug 260 to be broken out (see Fig. 4a and Fig. 4b -> Product 200, slug 260, recess 262). If product 200 is a thermoformed product produced by deforming a plastic film using a thermoforming tool, the step of creating the recess 262 at the desired position of product 260 can be carried out essentially simultaneously with the forming of product 260. In other words, the thermoforming tool (either the lower tool part or the upper tool part or both) is designed such that it is intended to produce this additional recess at the position of the die-cut slug.

[0028] In a subsequent second step S20, the slug 260 is punched out at the position where the indentation was created. The punching essentially separates the slug 260 to be broken out from the surrounding product 200. After punching, the slug 260 is only separated by one or more (in the Fig. 4a-4d are connected to the product 200 by two holding points 200a, 200b. The stamped slug 260 includes the surface recess 262 created in step S10. The stamping tool for stamping the slug 260 can be integrated into the thermoforming tool or attached separately to the thermoforming machine.

[0029] In a subsequent third step S30, the stamped slug 260 is then broken out using a stripping tool. The stripping tool can include a stripping plunger (hereinafter referred to as plunger) which is dimensioned such that it can engage in the created recess 262 of the slug 260.

[0030] A key aspect of the invention is that the recess 262 of the slug 260 and the stripping tool (or the plunger) are dimensioned such that, during a stripping operation, the stripping tool (or the plunger) can engage in the recess 262 of the slug 260. The technical effect of the recess 262 is described in connection with the Fig. Sections 4a to 4d are described further.

[0031] Fig. Figure 4a shows a portion of a product 200 (top view) in which a slug 260 has been punched. The slug 260 is connected to the product 200 via two opposing holding points 200a and 200b. As shown in the Fig. 4a and Fig. As can be seen in Figure 4b, the butt 260 has a recess 262. The recess 262 is designed to partially receive the plunger.

[0032] In the Fig. Figures 4b-4d further illustrate the breaking-out process caused by the plunger with the help of arrow 20. By moving the plunger downwards (see arrow 20 in the Fig. 4b-4d) the plunger first comes into contact with the butt 260 and pushes it downwards ( Fig. 4b). Due to the downward pushing motion of the plunger, one of the two opposing holding points 200a, 200b (left holding point in) breaks first. Fig. 4c).

[0033] The Butzen 260 now introduces the features associated with the Fig. The lateral tilting movement described in 2a-2d occurs because the butt is at the other holding point (right holding point 220b in Fig. 4c) still remains stuck. Due to the recess 262 and the at least partial engagement of the plunger in the recess 262 of the shank 260, the plunger cannot slide past the shank 260, as is the case, for example, in connection with Fig. The configuration described in 2c is possible. Rather, the plunger comes into contact with the side wall 264 of the recess. Through the further downward movement of the plunger, a continuous pressure force is exerted on the side wall 264 (and thus on the lump 260) until finally the right retaining point 220b also breaks and the lump 260 is completely detached from the product ( Fig. 4d).

[0034] The effect of the present invention will be demonstrated by means of the manufacturing process in the Fig. 4a to 4d are immediately apparent. Because the slug has a recess into which the stripping tool (plunger) can engage, the plunger is prevented from slipping past the slug during stripping. This ensures the reliable stripping of small stamped slugs from a product.

Claims

[1] Method for breaking out a stamped slug from a product (200), comprising: - Punching a slug (260) at a desired position in the product (200), wherein the punched slug (260) remains connected to the product (200) after the punching process by at least one holding point (200a, 200b) or holding film; - Creating a depression (262) in the area of ​​the die-cutting slug (260), wherein the step of creating the depression (262) and the step of die-cutting the slug are carried out simultaneously, or the step of creating the depression (262) is carried out before the step of die-cutting the slug (260); and - Breaking out the punched slug (260) by means of a breaking tool, wherein the produced recess (262) is dimensioned such that during breaking out the breaking tool or a part thereof comes into engagement with the recess (262). [2] Method according to claim 1, wherein the punch slug (260) is broken out using a plunger of the breaking tool. [3] Method according to claim 2, wherein the produced depression (262) is dimensioned such that when breaking out the plunger of the breaking tool engages with the produced depression (262). [4] Method according to any of the preceding claims, wherein the product (200) is a thermoformed product formed by thermoforming a plastic film using a thermoforming tool arranged in a thermoforming machine. [5] Method according to claim 4, wherein the recess (262) is thermoformed by means of a thermoforming tool arranged in the thermoforming machine. [6] Method according to claim 4 or 5, wherein the depression (262) is embossed on the surface of the die (260) by means of an embossing tool arranged in the thermoforming machine. [7] Method according to any one of claims 4 to 6, wherein the step of punching the slug (260) is carried out by means of a punching tool arranged in the thermoforming machine. [8] Method according to any one of claims 4 to 7, wherein the punched slug (260) is broken out by means of a stripping tool arranged in the thermoforming machine. [9] Method according to any one of claims 4 to 7, wherein the punch slug (260) is broken out by means of a breakout tool integrated in a stacking unit. [10] Device for breaking out a stamped slug (260) from a product (200), comprising: - a punching tool designed for punching a slug (260) at a desired position in the product (200); - a forming tool designed to produce a depression (262) on the surface of the die (260), wherein the forming tool and the die are designed to perform the production of the depression (262) in the die (260) and the die-cutting of the die (260) simultaneously or to produce the depression in the die (260) before die-cutting the die; and - a stripping tool designed for stripping the stamped slug (260), wherein the stripping tool is dimensioned such that during stripping the stripping tool or a part thereof engages with the recess (262) of the slug (260). [11] Device according to claim 10, wherein the forming tool is designed for thermoforming the recess (262). [12] Device according to claim 10, wherein the forming tool is an embossing tool provided for embossing the depression (262) on the surface of the die (260). [13] Thermoforming machine for thermoforming a product (200), comprising: - a thermoforming tool designed for forming the product (200); - the device according to claims 10 to 12 for producing and breaking out a punched slug (260) in the product (200). [14] Thermoforming machine according to claim 13, wherein the forming tool of the device is integrated in the thermoforming tool. [15] Thermoforming machine according to claim 13 or claim 14, wherein the punching tool of the device is integrated in the thermoforming tool or is arranged in a punching station of the thermoforming machine downstream of the thermoforming tool. [16] Thermoforming machine according to one of claims 13 to 15, wherein the stripping tool of the device is arranged in the thermoforming tool, in a punching station downstream of the thermoforming tool or in a stripping station of the thermoforming machine.

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