Controlling cross-web layer profile of a multilayer polymer film

Patent metadata

Field	Value
Publication number	US-9393729-B2
Application number	US-201113522061-A
Country	US
Kind code	B2
Filing date	Jan 10, 2011
Priority date	Jan 15, 2010
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A method is disclosed that includes forming a plurality of polymer layers via a plurality of slots, wherein the plurality of layers are combined to generate a multilayer polymer flow stream; and controlling heat flow to the plurality of slots in conjunction with the formation of the plurality of polymer layers. The multilayer polymer flow stream may be used to generate a multilayer film. In some embodiments, the cross-web layer thickness profile may be controlled by controlling heat flow to the plurality of slots that form the plurality of polymer layers.

First claim

The invention claimed is:

1. A method comprising:
forming a plurality of polymer layers via a plurality of slots, wherein each slot of the plurality of slots includes a first end, a second end, and an elongated opening extending from the first end and the second end in a cross-web direction;
controlling heat flow to an edge of at least one of the first end or the second end of each slot of the plurality of the slots in conjunction with the formation of the plurality of polymer layers; and
combining the plurality of polymer layers to generate a multilayer polymer flow stream, wherein the heat flow to the edge of the at least one of the first end or the second end controls a cross-web layer thickness profile of a multilayer polymer film generated from the multilayer polymer flow stream;
wherein controlling the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of the slots comprises controlling the heat flow to the first end of each slot, wherein the heat flow is controlled via at least one heater located adjacent the first end of each slot, and wherein the first end is between the at least one heater and the elongated opening of each slot.

2. The method of claim 1 , wherein controlling heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots comprises selectively providing heat flow to the edge of the at least one of the first end or the second end of at least one slot of the plurality of slots.

3. The method of claim 1 , further comprising determining the cross-web layer thickness profile of the multilayer polymer film generated from the multilayer polymer flow stream, wherein controlling the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of the slots comprises controlling the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of the slots based on the determined cross-web layer thickness profile of the multilayer polymer film.

4. The method of claim 3 , further comprising comparing the cross-web layer thickness profile to a target cross-web layer thickness profile to determine one or more profile deviations, wherein controlling the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of the slots based on the determined cross-web layer thickness profile of the multilayer polymer film comprises controlling the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of the slots based on the one or more determined profile deviations.

5. The method of claim 1 , wherein the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots is configured to create a temperature gradient in the cross-web direction within at least one slot of the plurality of slots.

6. The method of claim 5 , wherein the temperature gradient is sufficient to promote polymer flow within a first portion of the at least one slot.

7. The method of claim 1 , wherein the multilayer polymer flow stream includes a plurality of first layers comprising a first polymer and a plurality of second layers comprising a second polymer different than the first polymer.

8. The method of claim 1 , further comprising generating the multilayer polymer film from the multilayer polymer flow stream.

9. A multilayer film system comprising:
a feedblock including a plurality of slots configured to form a plurality of polymer layers that are subsequently combined to generate a multilayer polymer flow stream, wherein each slot of the plurality of slots includes a first end, a second end, and an elongated opening extending from the first end and the second end in a cross-web direction; and
at least one heater proximate the plurality of slots configured to control heat flow to an edge of at least one of the first end or the second end of each slot of the plurality of slots in conjunction with the formation of the plurality of polymer layers, wherein the heat flow to the edge of the at least one of the first end or the second end controls a cross-web layer thickness profile of a multilayer polymer film generated from the multilayer polymer flow stream;
wherein the at least one heater is configured to control the heat flow to the first end of each slot, wherein the at least one heater is located adjacent the first end of each slot, and wherein the first end is between the at least one heater and the elongated opening of each slot.

10. The system of claim 9 , wherein the at least one heater is configured to control the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots at least in part by selectively providing heat flow to at least one slot of the plurality of slots.

11. The system of claim 9 , wherein the at least one heater is configured to control the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots at least in part by at least one of initiating heat flow from the at least one heater, adjusting heat flow from the at least one heater, or terminating heat flow from the at least one heater to the edge of the at least one of the first end or the second end of at least one slot of the plurality of slots.

12. The system of claim 9 , further comprising a monitoring device configured to determine the cross-web layer thickness profile of a multilayer polymer film generated from the multilayer polymer flow stream, wherein the at least one heater is configured to control the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots based at least in part on the determined cross-web layer thickness profile of the multilayer polymer film.

13. The system of claim 12 , wherein the at least one heater is configured to control the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots based at least in part on one or more profile deviations determined by a comparison of the determined cross-web layer thickness profile to a target cross-web layer thickness profile.

14. The system of claim 9 , wherein the heat flow to the edge of the at least one of the first end or the second end of each slot of the plurality of slots creates a temperature gradient in the cross-web direction within at least one slot of the plurality of slots.

15. The system of claim 14 , wherein the temperature gradient is sufficient to promote polymer flow within a first portion of the at least one slot.

16. The system of claim 9 , wherein the at least one heater comprises a first heater configured to provide heat flow to the edge of the first end of at least one slot of the plurality of slots.

17. The system of claim 16 , further comprising a second heater configured to provide heat flow to the edge of the second end of the at least one slot of the plurality of slots.

18. The system of claim 9 , wherein the multilayer polymer flow stream includes a plurality of first layers comprising a first polymer and a plurality of second layers comprising a second polymer different than the first polymer.

19. The system of claim 9 , further comprising generating a multilayer polymer film from the multilayer polymer flow stream.

20. The system of claim 9 , wherein the at least one heater extends substantially along the e

Assignees

• Derks Kristopher J
• Biegler Robert M
• Neavin Terence D
• 3M Innovative Properties Co

Inventors

• Derks Kristopher J
• Biegler Robert M
• Neavin Terence D

Classifications

• B29C48/71

  for layer multiplication (extrusion of multi-component articles B29C48/16) · CPC title

• B29C2948/92438

  Conveying, transporting or storage of articles · CPC title

• B29L2011/00

  Optical elements, e.g. lenses, prisms · CPC title

• B29L2007/00

  Flat articles, e.g. films or sheets (B29L2024/00 takes precedence) · CPC title

• B29C48/695 Primary

  Flow dividers, e.g. breaker plates · CPC title