RELATED PUNCHING TOOLS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No.

62/719,920, filed August 20, 2018, the content of which is incorporated herein by reference.

FIELD

[0002] The invention relates to the formation of perforations in flexible films, and more particularly, to improved systems and methods of forming perforations in such flexible films.

BACKGROUND

[0003] Flexible films are often used in packaging, for example, in the food packaging industry (e.g., fruit packaging, vegetable packaging, etc.). Perforations/apertures are sometimes formed in such flexible films. Such perforations may be formed, for example, using laser systems and needle based systems. Conventional perforation systems tend to suffer from various deficiencies such as, for example: high cost of ownership; high cost of use; poor uniformity of perforations; poorly shaped perforations; etc.

[0004] Thus, it would be desirable to provide improved systems and methods of forming perforations/apertures in a flexible film.

SUMMARY

[0005] According to an exemplary embodiment of the invention, a system for forming apertures in a flexible film is provided. The system includes a punching tool for forming apertures in a flexible film. The punching tool defines a through hole therethrough. The system also includes a support plate. The punching tool is configured to press the flexible film against the support plate to form the apertures. [0006] According to another exemplary embodiment of the invention, a method of forming an aperture in a flexible film is provided. The method includes the steps of: providing a support plate; and pressing a flexible film against the support plate using a punching tool for forming the aperture, the punching tool defining a through hole therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is best understood from the following detailed description when read in connection with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity.

[0008] FIGS. 1A-1B are block diagrams of two punching members, including corresponding punching tools, in accordance with exemplary embodiments of the invention;

[0009] FIG. 2 is a block diagram of an array of punching members in accordance with an exemplary embodiment of the invention;

[0010] FIG. 3 is a top view of three tool holders including respective arrays of punching members in accordance with exemplary embodiments of the invention;

[0011] FIGS. 4A-4B are side, and top, block diagram views of a system for forming perforations/apertures in a flexible film in accordance with an exemplary embodiment of the invention;

[0012] FIGS. 5A-5B are side, and top, block diagram views of another system for forming perforations/apertures in a flexible film in accordance with another exemplary embodiment of the invention;

[0013] FIGS. 6A-6D are a series of block diagrams illustrating a method of forming a perforation/aperture in a flexible film in accordance with an exemplary embodiment of the invention; [0014] FIGS. 7A-7C are a series of enlarged, cross-sectional block diagrams of a working tip of a punching tool illustrating a method of forming a perforation/aperture in a flexible film in accordance with an exemplary embodiment of the invention;

[0015] FIGS. 8A-8B are side and top block diagram views of a support plate in accordance with an exemplary embodiment of the invention;

[0016] FIGS. 9A-9B are side and top block diagram views of another support plate in accordance with another exemplary embodiment of the invention; and

[0017] FIGS. 10A-10B are side and top block diagram views of yet another support plate in accordance with yet another exemplary embodiment of the invention.

DETAILED DESCRIPTION

[0018] FIGS. 1A-1B illustrate punching members 100a, 100b. Each of punching members 100a, 100b includes a sleeve lOOal (e.g., a metal sleeve, etc.). A punching tool lOObl, 100b2 is inserted into sleeve lOOal. For example, punching tools lOObl, 100b2 are held in their respective sleeve lOOal using an adhesive, a fastener (e.g., a screw, bolt, etc.), or holding mechanism or method. A spring lOOcl is provided around a portion of each of the sleeves lOOal. It is noteworthy that punching members 100a, 100b are different from each other because they include different punching tools lOObl, 100b2. Exemplary punching tools may be formed from a ceramic material (e.g., an alumina material, a zirconia toughened alumina material, a ruby material, a silicon nitride material, etc.).

[0019] Punching tools lOObl, 100b2 each define a through hole lOOel, 100e2 extending from (i) a top of the punching tool (where the top of the tool is engaged in the sleeve lOOal) to (ii) a working tip lOOdl, 100d2 of the respective punching tool lOObl, 100b2. Punching tools in accordance with the invention may be ground or otherwise formed to have a desired shape, particularly in the area of the working tip. As shown in the examples provided in FIGS. 1A-1B, the punching tools lOObl, 100b2 are cylindrical in shape, and include a tapered portion lOOfl, 100f2 terminating at a working tip lOOdl, 100d2, and each define a respective through hole lOOel, 100e2. A desirable aspect of the invention is that punching tools may have different features, for example, different working tip designs. FIGS. 1A-1B illustrate that working tip lOOdl of punching tool lOObl is different from working tip 100d2 of punching tool 100b2. In a specific example, the outer diameter of the cylindrical body of the punching tools may be the same, but the working tip may be different.

[0020] FIG. 2 illustrates a plurality of punching members 100a, 100b held by a tool holder 102. Any number of punching members 100a, 100b (including corresponding punching tools lOObl, 100b2), in any number of rows, may be held by tool holder 102. A given tool holder 102 may carry punching members 100a, 100b (or other punching members) having different styles or models of punching tools lOObl, 100b2.

[0021] FIG. 3 illustrates three (3) different tool holders 102. Each of the tool holders 102 has the same design, with the same number of rows, and the same number of receivers (e.g., holes) for receiving punching members (e.g., punching members 100a, 100b, or other punching members). Each of the three (3) tool holders 102 shown in FIG. 3 holds different numbers of punching members in different locations. As shown in FIG. 3, an empty receiver in tool holder 102 is shown as hole 102b, whereas a filled receiver (e.g., filled with a punching member) in tool holder 102 is shown as filled hole 102a.

[0022] FIGS. 4A-4B and 5A-5B illustrate respective example systems 10a, 10b configured to form perforations in a flexible film 120. Systems 10a, 10b each include a feed system for feeding a flexible film 120. In the examples shown, the feed systems each include a source spool 116 that provides the flexible film 120 for processing (e.g., perforating) using respective system 10a, 10b. The feed systems also include a downstream spool 118 configured to receive the flexible film 120 after perforation. Systems 10a, 10b also each include a support plate 104. The punching tools (e.g., see punching tools lOObl, 100b2 in FIGS. 1A-1B) are configured to press flexible film 120 against support plate 104 to form the apertures.

[0023] Systems 10a, 10b also include: a tool holder 102 carrying a plurality of punching members (including corresponding punching tools); a striking tool 106 (including a plurality of striking members 106a being aligned to strike against a corresponding one of the plurality of punching tools (e.g., punching tools lOObl, 100b2, or other punching tools) through contact with the corresponding punching sleeve 100a 1) configured to strike against the punching tool (through the punching sleeve lOOal) such that each punching tool presses the flexible film 120 against support plate 104 to form the apertures (e.g., see aperture 120a in FIGS. 7B-7C); and a holding plate 108 for holding flexible film 120 against support plate 104. Holding plate 108 defines a plurality of holes through which working tips (e.g., see working tips lOOdl, 100d2 in FIGS. 1A-1B) of the punching tools extends during pressing.

[0024] Systems 10a, 10b also include (illustrated in block diagram form) : a control system 400 for controlling operation of system 10a, 10b including controlling the punching tool lOObl, 100b2 pressing the flexible film 120 against the support plate 104 to form the apertures 120a; an inspection system 402 (e.g., including a camera and/or other imaging elements, and image processing tools) for inspecting the apertures 120a formed using the punching tool lOObl, 100b2; and a cleaning system 404 for collecting cut portions of the flexible film 120 caused by forming the apertures 120a.

[0025] In FIGS. 4A-4B, system 10a is configured to form apertures in a flexible film 120 in a static configuration. More specifically, during each cycle of pressing to form apertures in flexible film 120, flexible film 120 is not in motion. In contrast, in FIGS. 5A- 5B, system 10b (including the same basic elements as in system 10a of FIGS. 4A-4B) is configured to form apertures (e.g., see apertures 120a in FIGS. 7B-7C) in a flexible film 120 in a dynamic configuration. More specifically, during each cycle of pressing to form apertures 120a in flexible film 120, flexible film 120 is in motion (e.g., see two arrows pointing to the right in FIG. 5B, showing motion of flexible film 120).

[0026] FIGS. 6A-6D are a series of block diagrams illustrating a method of forming a perforation in a flexible film. FIG. 6A illustrates the configuration before contact between striking member 106a and punching member lOOa/lOOb (i.e., in FIGS. 6A-6D any punching member, such as punching member 100a or 100b, may be utilized). In FIG. 6B, striking member 106a (as part of striking tool 106) is lowered to contact punching member lOOa/lOOb. As shown in FIG. 6B, the interconnection between striking tool 106 (which carries striking member 106a) and holding plate 108 results in the lowering of holding plate 108, and in holding plate 108 holding the flexible film 120 against support plate 104. In FIG. 6C, punching member lOOa/lOOb has descended to form a perforation in flexible film 120 (detailed in FIGS. 7A-7C) via punching tool 100bl/100b2. In FIG. 6D, striking tool 106 (carrying striking member 106a) has been raised to restore the position of the elements of the system to their location in FIG. 6A. While FIGS. 6A-6D illustrate a single striking member 106a striking a single punching member lOOa/lOOb to operate a single punching tool 100bl/100b2, it is understood that any number of striking members 106a (and punching members lOOa/lOOb and punching tools 100bl/100b2) may be arranged in any number of columns and rows, and operated concurrently, to form a number of perforations in the flexible film 120.

[0027] FIGS. 7A-7C are a series of block diagrams of a working tip lOOdl, 100d2 of a punching tool lOObl, 100b2. That is, different types of punching tools (with different features) may be utilized. For simplicity, in FIGS. 7A-7C (and in other parts of the application), punching tools lOObl, 100b2 are shown. It is understood that if punching tool lOObl is used, it will have working tip lOOdl as shown in FIG. 1A. Likewise, if punching tool 100b2 is used, it will have working tip 100d2 as shown in FIG. IB. In FIG. 7A, working tip lOOdl, 100d2 is approaching flexible film 120. In FIG. 7B, working tip lOOdl, 100d2 has cut (or otherwise perforated) flexible film 120 to form an aperture 120a in flexible film 120. At least a portion of an upper surface of support plate 104 is formed of a compliant material (e.g., a rubber material, another compliant material, etc.) such that pressing of flexible film 120 against the upper surface using the punching tool results in deformation of the upper surface. The deformation of the upper surface results in formation of a shaped portion 104' of the upper surface adjacent through hole lOOel, 100e2 in punching tool lOObl, 100b2. The shaped portion 104' forces a cut portion 120' of flexible film 120 into through hole lOOel, 100e2 of punching tool lOObl, 100b2. This cut portion 120' may continue up further into through hole lOOel, 100e2 in connection with a cleaning system (e.g., see cleaning system 404 in FIGS. 4A-4B and FIGS. 5A-5B). For example, the cleaning system may simply be used to collect cut portions 120' in the through hole lOOel, 100e2 until they require removal. Further, a vacuum or other system may be utilized to remove the cut portions 120' from the through holes lOOel, 100e2, or from the system before entry into the through holes lOOel, 100e2. Further still, a different type of cleaning system may be utilized such as a brush based cleaning system for removing the cut portions 120' from the flexible film 120.

[0028] FIGS. 8A-8B, 9A-9B, and 10A-10B illustrates three (3) different examples of at least a portion of an upper surface of support plate 104 being formed of a compliant material. Each of FIGS. 4A-4B, 5A-5B, 6A-6D and FIGS. 7A-7C refer to a support plate 104. Examples of such a support plate 104 are shown in FIGS. 8A-8B (i.e., support plate 104a), FIGS. 9A-9B (i.e., support plate 104b), and FIGS. 10A-10B (i.e., support plate 104c). Any of these support plates, or others within the scope of the invention, may be support plate 104 of FIGS. 4A-4B, 5A-5B, 6A-6D and FIGS. 7A-7C. In FIGS. 8A-8B, a two layer support plate 104a is illustrated including an upper (compliant) layer 104al on a lower layer 104a2 (e.g., where the lower layer may be formed of a different, more rigid, material as compared to the upper layer) (e.g., where an exemplary material of the lower layer is steel). In FIGS. 9A-9B, a support plate 104b (formed of a unitary piece of material, such as a compliant material) is provided. In FIG. 10A-10B, compliant material inserts 104c2 are provided in base apertures 104c3 of base structure 104cl (where compliant material inserts 104c2 align with punching tools lOObl, 100b2 which will press a flexible film against compliant material inserts 104c2 in connection with the formation of apertures 120a).

[0029] Apertures (e.g., perforations) 120a formed using the inventive systems and methods described herein may have improved characteristics such as uniformity, circularity, etc., particularly at small sizes. Exemplary ranges for the diameter of the apertures include: 45-150 microns; less than 200 microns; less than 150 microns; less than 100 microns; less than 75 microns; and less than 50 microns. Of course, larger apertures are also contemplated within the scope of the invention.

[0030] In accordance with certain exemplary embodiments of the invention, the working tip of the punching tool may be heated. The working tip may be heated through heat transfer between the working tip and : another portion of the punching tool, another portion of the punching member, and/or another portion of the system for forming the apertures.

[0031] Although the invention has been described and illustrated with respect to the exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without parting from the spirit and scope of the present invention. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.