Profiled Extrusion Replication

• US 20130037987A1
• Filed: 03/21/2011
• Published: 02/14/2013
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Clarke, Graham M., Eull, Patricia A., Peterson, Kenneth A., Slama, David F., Olsen, Lee E.
• Granted Patent: US 9,108,349 B2
• Time in Patent Office: Days
• US Class Current: 264/210.1
• CPC Class Codes: B29C 2043/463 corrugated, patterned or embossed surface
• CPC Class Codes: B29C 2043/468 take-off rollers, i.e. arranged adjacent a material feeding device
• CPC Class Codes: B29C 2948/92704 Temperature
• CPC Class Codes: B29C 2948/92923 Calibration, after-treatment or cooling zone
• CPC Class Codes: B29C 43/222 characterised by the shape of the surface
• CPC Class Codes: B29C 43/24 Calendering
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/305 having a wide opening, e.g. for forming sheets
• CPC Class Codes: B29C 48/35 with rollers
• CPC Class Codes: B29C 48/914 cooling drums
• CPC Class Codes: B29L 2007/008 Wide strips, e.g. films, webs

Abstract

A profiled extrusion replication process is disclosed that includes steps of (a) extruding a molten material through an extrusion die having at least one profiled die lip to form a molten extrudate having first and second major extrudate surfaces and having a first structural feature in the first major extrudate surface; (b) bringing the molten extrudate into contact with a tool surface comprising one or more second structural features so as to cause a portion of the first structural feature in the first major extrudate surface to contact the one or more second structural features on the tool surface; and (c) cooling the molten extrudate to provide the structured film. Structured films and apparatus for making structured films are also disclosed.

Claims

1. A process for making a structured film, comprising steps of:

(a) extruding a molten material through an extrusion die having at least one profiled die lip to form a molten extrudate having first and second major extrudate surfaces and having a first structural feature in the first major extrudate surface;

(b) bringing the molten extrudate into contact with a tool surface comprising one or more second structural features so as to cause a portion of the first structural feature in the first major extrudate surface to contact at least one of the second structural features on the tool surface; and

(c) cooling the molten extrudate to provide the structured film;

wherein a ratio of a cross-web cross-sectional area of the first structural feature to a cross-web cross-sectional area of a second structural feature is about 1.0.

2. The process of claim 1 wherein extruding a molten material comprises extruding the molten material vertically downward and into contact with the tool surface.

3. The process of claim 1, wherein extruding a molten material comprises extruding one or more thermoformable materials selected from the group consisting of a polyolefin, an olefin-containing polymer, and combinations of two or more of the foregoing.

4. The process of claim 1, wherein extruding a molten material is performed using a single screw extruder.

5. The process of claim 1, wherein extruding a molten material is performed using a twin screw extruder.

6. The process of claim 1, wherein extruding a molten material comprises extruding one or more polymeric material selected from the group consisting of polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyamide, polyester, polycarbonate, polymethyleneoxide, polybutyleneterephthalate, styrene acrylonitrile copolymer, styrene (meth)acrylate copolymer, styrene maleic anhydride copolymer, nucleated semi-crystalline polyester, polyethylenenaphthalate copolymer, polyimide copolymer, polyetherimide, polyethylene oxide, polyacrylonitrile-co-polybutadiene-co-polystyrene, and combinations of two or more of the foregoing.

7. The process of claim 1, wherein extruding a molten material comprises extruding one or more polymeric material from the group consisting of cyclic olefin copolymers, polyethylene naphthalate, polyethylene terephthalate, polyacrylate, polymethylmethacrylate, polycarbonate, polymethylpentene, styrene acrylonitrile, and combinations of two or more of the foregoing.

8. The process of claim 1, wherein bringing the molten extrudate into contact with a tool surface in step b) comprises nipping the molten extrudate between the tool surface and a nip roll, wherein the tool surface is a surface on a tool roll.

9. The process of claim 8 wherein at least one of the nip roll or the tool roll is cooled.

10. The process of claim 1, wherein bringing the molten extrudate into contact with a tool surface in step b) comprises nipping the molten extrudate between the tool surface and a nip roll, wherein the tool surface is a surface on an endless belt.

11. The process of claim 1, wherein bringing the molten extrudate into contact with a tool surface in step b) comprises nipping the molten extrudate between the tool surface and a nip surface, wherein the nip surface is a surface on an endless belt.

12. The process of claim 1 wherein step b) occurs at a temperature above a glass transition temperature of the molten extrudate.

13. The process of claim 1 wherein the portion of the first structural feature contacts at least two of the second structural features located on the tool surface.

15. A structured film made according to the process of claim 1.

14. (canceled)

16. An apparatus for extrusion replication, comprising:

an extruder equipped with a profiled extrusion die having at least one profiled die lip; and

,

a tool having a structured surface positioned to receive molten extrudate from the profiled extrusion die.

17. The apparatus of claim 16, wherein the tool comprises a tool roll.

18. The apparatus of claim 16, wherein the tool comprises an endless belt.

21. The apparatus of claim 17, further comprising a nip roll to form a nip with the tool.

22. The apparatus of claim 21, wherein the nip roll has a structured surface.

23. The apparatus of claim 21, wherein the nip roll has a conformable surface.

19-20. -20. (canceled)