Forming mold cavities

• US 6,387,305 B1
• Filed: 09/27/2000
• Issued: 05/14/2002
• Est. Priority Date: 08/25/1997
• Status: Expired due to Term

• Current Assignee: Velcro BVBA
• Original Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Inventors: Babineau, James W., Fryklund, Gilbert G., Harvey, Andrew C., Jens, Stephen C.
• Primary Examiner(s): McDowell, Suzanne E.
• Application Number:
  US09/671,958
• Time in Patent Office: 594 Days
• Field of Search: 264/81, 264/219, 204/192.15, 205/149, 205/151, 205/182, 205/186, 205/187, 427/250, 427/405
• US Class Current: 264/81
• CPC Class Codes: A44B 18/0049 obtained by moulding processes compression moulding or articles of indefinite length characterised by the shape of the surface B29C43/222; screen moulding B29C67/08
• CPC Class Codes: B29C 2043/023 having a plurality of grooves
• CPC Class Codes: B29C 2043/3678 on cylindrical supports with moulds or mould cavities provided on the periphery
• CPC Class Codes: B29C 2043/461 the rollers having specific surface features
• CPC Class Codes: B29C 2043/465 having one or more cavities, e.g. for forming distinct products
• CPC Class Codes: B29C 33/302 Assembling a large number of mould elements to constitute one cavity
• CPC Class Codes: B29C 33/3857 by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
• CPC Class Codes: B29C 43/222 characterised by the shape of the surface
• CPC Class Codes: B29C 43/46 Rollers
• CPC Class Codes: B29C 45/2673 with exchangeable mould parts, e.g. cassette moulds B29C45/1756 takes precedence
• CPC Class Codes: B29C 45/2675 Mounting of exchangeable mould inserts
• CPC Class Codes: B29C 59/025 Fibrous surfaces with piles or similar fibres substantially perpendicular to the surface
• CPC Class Codes: B29L 2031/729 Hook and loop-type fasteners
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10S 425/814 Zipper

Abstract

A method for producing a multiplicity of miniature cavities extending from a mold surface for molding a plastic product having features integrally molded with and extending from a product base, and a mold so produced. The mold cavities are formed by depositing multiple layers of plating material on a workpiece in a predetermined pattern selected to produce a desired mold cavity shape. The mold may be in the form of a roll or belt for continuous processing, or in any form for discrete injection molding. The invention is particularly applicable to the production of touch fastener products, such as those with arrays of miniature hooks.

Claims

1. A method of producing a multiplicity of miniature mold cavities extending from a common surface, for molding a plastic product having a corresponding multiplicity of miniature features integrally molded with and extending from a common base, the method comprising

depositing multiple layers of plating material onto a workpiece in predetermined patterns selected to produce desired mold cavity shapes such that the deposited plating material defines the multiplicity of miniature mold cavities and the common surface.

2. The method of claim 1 wherein the cavities each have a crook, for molding a fastener element with an engageable crook portion.

3. The method of claim 2 wherein the cavities are constructed to mold hook-shaped fastener elements.

4. The method of claim 1 wherein the miniature mold cavities are constructed to mold elements that extend less than about 0.050 inch from the common surface.

5. The method of claim 4 wherein the miniature mold cavities are constructed to mold elements that extend less than about 0.025 inch from the common surface.

6. The method of claim 1 wherein the workpiece comprises at least part of a mold for molding a plastic fastener product.

7. The method of claim 6 comprising

applying a masking material to selected portions of the workpiece to produce masked surfaces,

depositing a layer of said plating material to the workpiece to surfaces other than the masked surfaces, and

removing the masking material from the masked surfaces to expose unplated surfaces of the workpiece.

8. The method of claim 6 wherein the workpiece comprises a flat plate, the plating material being deposited on one broad side of the plate to form mold surfaces at an edge thereof, for defining mold cavities extending from said edge.

9. The method of claim 8 wherein the plating material is deposited to form one side of a mold cavity, another side of the cavity being defined by a surface of an adjoining plate.

10. The method of claim 8 further comprising the step of machining the deposited plating material to remove an outer portion thereof to provide a flat surface for abutting an adjoining mold part.

11. The method of claim 6 wherein the plating material defines fully-formed mold cavities, each extending from an innermost portion to a base portion at an outer surface of the plating, the layers of deposited plating material defining, in order of deposition, said cavities from their innermost portions to their base portions.

12. The method of claim 11 wherein the workpiece comprises a flexible belt.

13. The method of claim 1 wherein the overall thickness of the multiple layers of plating material is between about 0.001 inch and 0.015 inch.

14. The method of claim 13 wherein the overall thickness of the multiple layers of plating material is between about 0.002 inch and 0.007 inch.

15. The method of claim 14 wherein the overall thickness of the multiple layers of plating material is about 0.004 inch.

16. The method of claim 1 wherein the workpiece comprises a master, the method further comprising the step of removing the master from the plating to form a mold for molding a plastic fastener product.

17. The method of claim 16 wherein the master has fastener elements extending from a surface of the product base.

18. The method of claim 17 wherein the fastener elements are hook-shaped.

19. The method of claim 16 wherein the mold comprises a cylindrical mold sleeve with fully-formed mold cavities extending inward from its outer surface.

20. The method of claim 16 wherein the mold has an overall thickness of between about 0.005 inch and 0.050 inch.

21. The method of claim 16 comprising depositing a layer of metal on the master before depositing the plating material.

22. The method of claim 21 wherein the metal comprises copper.

23. A method of producing a mold defining an array of mold cavities extending from a common surface, for producing an array of plastic elements integrally molded with and extending from a broad side of a base, the method comprising

providing a master having a surface from which an array of master features extend, the features having shapes corresponding to the shapes of the elements to be molded;

depositing plating material across the surface of the master to cover the master features; and

removing the master from the deposited plating material to expose an array of cavities extending into the plating material, each cavity corresponding to a master feature and shaped for molding an element therein.

24. The method of claim 23 wherein the mold cavities have crooks, for molding fastener elements with engageable crook portions.

25. The method of claim 24 wherein the mold cavities are constructed to mold hook shaped fastener elements.

26. The method of claim 23 wherein the mold cavities extend less than about 0.050 inch from the common surface.

27. The method of claim 26 wherein the mold cavities extend less than about 0.025 inch from the common surface.

28. The method of claim 23 wherein the deposited plating material has an overall thickness of between about 0.001 inch and 0.015 inch.

29. The method of claim 28 wherein the deposited plating material has an overall thickness of between about 0.002 inch and 0.007 inch.

30. The method of claim 29 wherein the overall thickness of the deposited plating material is about 0.004 inch.

31. The method of claim 23 wherein the master features are of molded plastic.

32. The method of claim 31 wherein the master features are hook-shaped.

33. The method of claim 23 wherein the deposited plating material forms a cylindrical mold sleeve with the cavities extending radially inward from an outer surface thereof.

34. The method of claim 33 wherein the deposited plating material has an overall thickness of between about 0.005 inch and 0.050 inch.

35. The method of claim 23 wherein the step of de positing comprises depositing a layer of copper on the master.

36. A method of producing a mold roll defining an array of cavities extending inward from a peripheral surface, for continuously molding an array of fastener element features exteniding from a sheet-form base, the method comprising

providing a master having a surface from which an array of master features extend, the master features having shapes corresponding to the shapes of fastener element features to be molded;

arranging the master inside a rigid sleeve;

depositing plating material across the surface of the master to cover the master features and form a cylindrical mold sleeve of plating material; and

removing the master from the deposited plating material to expose an array of cavities extending into the mold sleeve from a peripheral surface thereof, each cavity corresponding to a master feature and shaped for molding a fastener element feature therein.

37. The method of claim 36 wherein the mold cavities have crooks, for molding fastener elements with engageable crook portions.

38. The method of claim 37 wherein the mold cavities are shaped to mold hook-shaped fastener elements.

39. The method of claim 36 wherein the mold cavities extend less than about 0.050 inch from the peripheral surface.

40. The method of claim 39 wherein the mold cavities extend less than about 0.025 inch from the peripheral surface.

41. The method of claim 40 wherein the deposited plating material has an overall thickness of between about 0.001 inch and 0.015 inch.

42. The method of claim 41 wherein the deposited plating material has an overall thickness of between about 0.002 inch and 0.007 inch.

43. The method of claim 36 wherein the master features comprise fastener elements extending from a surface of the master.

44. The method of claim 43 wherein the fastener elements of the master are hook-shaped.

45. The method of claim 36 wherein the step of depositing comprises depositing a layer of copper on the master.