Vented tooling belt for production of structured surfaces

Patent metadata

Field	Value
Publication number	US-9817163-B2
Application number	US-201615099679-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Apr 15, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Various geometries are described for forming retroreflective structures in polymeric sheets or films. The geometries enable venting of volatile gases that can otherwise become trapped between the embossing surface and the polymeric sheet or film. The geometries are incorporated in tooling belts or other pattern forming surfaces.

First claim

What is claimed is:

1. A method for reducing occurrence of gases trapped between tooling and a polymeric sheet during manufacture of retroreflective materials, the method comprising:
providing a substrate defining opposite peripheral edges and a molding surface extending between the edges, the molding surface including a plurality of prismatic structures, the plurality of prismatic structures defining an average structure height, the molding surface including a plurality of channels extending across at least a portion of the molding surface, the channels defining an average depth of from 5% to 50% of the average structure height;
providing a polymeric sheet defining at least one face;
embossing a pattern of the plurality of prismatic structures from the substrate to the face of the polymeric sheet;
wherein during the embossing, gases disposed between the substrate and the polymeric sheet are urged through at least a portion of the channels, thereby reducing occurrence of trapped gases.

2. The method of claim 1 wherein the average depth of the channels is from 10% to 15% of the average structure height.

3. The method of claim 1 wherein the substrate is metal.

4. The method of claim 1 wherein the prismatic structures are triangles arranged so as to define a plurality of baselines separating each triangle from an adjacent triangle.

5. The method of claim 4 wherein the plurality of baselines include a first set of baselines oriented parallel to one another, a second set of baselines oriented parallel to one another and at 60 degrees from the first set of baselines, and a third set of baselines oriented parallel to one another and at 60 degrees from the second set of baselines and at 60 degrees from the first set of baselines.

6. The method of claim 5 wherein the plurality of channels include at least one channel extending along at least one of the first set of baselines, at least one channel extending along at least one of the second set of baselines, and at least one channel extending along at least one of the third set of baselines.

7. The method of claim 6 wherein the plurality of channels extending along at least one of the first set of baselines includes two channels separated by another of the first baselines.

8. The method of claim 7 wherein the plurality of channels extending along at least one of the second set of baselines includes two channels separated by another of the second baselines.

9. The method of claim 8 wherein the plurality of channels extending along at least one of the third set of baselines includes two channels separated by another of the third baselines.

10. A retroreflective material produced using the method of claim 1 .

11. The retroreflective material of claim 10 selected from the group consisting of signage, construction barriers, traffic barriers, and personal protection gear.

12. Tooling for forming a pattern of microstructures, the tooling comprising:
a substrate defining opposite peripheral edges and a molding surface extending between the edges, the molding surface including a plurality of prismatic structures, the plurality of prismatic structures defining an average structure height, the molding surface including a plurality of channels extending across at least a portion of the molding surface, the channels defining an average depth of from 5% to 50% of the average structure height.

13. The tooling of claim 12 wherein the plurality of channels provide access along at least one of the edges.

14. The tooling of claim 12 wherein the average depth of the channels is from 10% to 15% of the average structure height.

15. The tooling of claim 12 wherein the substrate is metal.

16. The tooling of claim 12 wherein the prismatic structures are triangles arranged so as to define a plurality of baselines separating each triangle from an adjacent triangle.

17. The tooling of claim 16 wherein the plurality of baselines include a first set of baselines oriented parallel to one another, a second set of baselines oriented parallel to one another and at 60 degrees from the first set of baselines, and a third set of baselines oriented parallel to one another and at 60 degrees from the second set of baselines.

18. The tooling of claim 17 wherein the plurality of channels include at least one channel extending along at least one of the first set of baselines, at least one channel extending along at least one of the second set of baselines, and at least one channel extending along at least one of the third set of baselines.

19. The tooling of claim 18 wherein the plurality of channels extending along at least one of the first set of baselines includes two channels separated by another of the first baselines.

20. The tooling of claim 19 wherein the plurality of channels extending along at least one of the second set of baselines includes two channels separated by another of the second baselines.

21. The tooling of claim 20 wherein the plurality of channels extending along at least one of the third set of baselines includes two channels separated by another of the third baselines.

22. A method for reducing occurrence of gases trapped between tooling and a polymeric sheet during manufacture of retroreflective materials, the method comprising:
providing a substrate defining opposite peripheral edges and a molding surface extending between the edges, the molding surface including a plurality of prismatic structures defined by baselines, the plurality of prismatic structures defining an average structure height, the molding surface including a plurality of passages, each passage located so as to extend across a baseline, the passages having an average depth of from 5% to 50% of the average structure height;
providing a polymeric sheet defining at least one face;
embossing a pattern of the plurality of prismatic structures from the substrate to the face of the polymeric sheet;
wherein during the embossing, gases disposed between the substrate and the polymeric sheet are urged through at least a portion of the passages, thereby reducing occurrence of trapped gases.

23. The method of claim 22 wherein each passage is located so as to extend perpendicular to a baseline.

24. The method of claim 22 wherein the average depth of the channels is from 10% to 15% of the average structure height.

25. The method of claim 22 wherein the substrate is metal.

26. The method of claim 22 wherein the prismatic structures are triangles arranged so as to define a plurality of baselines separating each triangle from an adjacent triangle.

27. A retroreflective material produced using the method of claim 22 .

28. The retroreflective material of claim 27 selected from the group consisting of signage, construction barriers, traffic barriers, and personal protection gear.

29. Tooling for forming a pattern of microstructures, the tooling comprising:
a substrate defining opposite peripheral edges and a molding surface extending between the edges, the molding surface including a plurality of prismatic structures defined by baselines, the plurality of prismatic structures defining an average structure height, the molding surface including a plurality of passages, each passage located so as to extend across a baseline, the passages having an average depth of from 5% to 50% of the average structure height.

30. The tooling

Assignees

• Avery Dennison Corp

Inventors

• Agashe Nikhil R
• Peck John D
• Galicia Ethelbert
• Chapman Steven R

Classifications

• B29D11/00

  Producing optical elements, e.g. lenses or prisms (grinding or polishing of optical elements B24B; constructional form of optical elements G02B; {optical parts of spectacles G02C7/00}) · CPC title

• B29C37/006 Primary

  Degassing moulding material or draining off gas during moulding (venting means in moulds B29C33/10) · CPC title

• B29D11/00605 Primary

  Production of reflex reflectors · CPC title

• B29C59/022

  characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor · CPC title

• B29C59/04

  using rollers or endless belts · CPC title