SYSTEM AND METHOD FOR CONTROLLING CURL IN MULTI-LAYER WEBS
First Claim
1. A method for reducing strain-induced curl in a multi-layer web, the method comprising:
- providing a coated web, the coated web including a coating applied to a web of indeterminate length, the coating being characterized by at least partially shrinking when cured;
curing the coating to form a multi-layer web, the multi-layer web including a strain induced by curing the coating; and
stretching the web during curing of the coating, wherein stretching the web substantially cancels the strain induced by curing such that the resulting multi-layer web is substantially flat.
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Accused Products
Abstract
A system and method for controlling curl in multi-layer webs. The method can include providing a coated web, curing the coating to form a multi-layer web, and stretching the web during curing of the coating. Some coatings shrink at least partially when cured such that curing the coating induces a strain in the multi-layer web. Stretching the web occurs during curing to induce an opposing strain that at least partially counteracts the strain induced by curing to form a multi-layer web having a desired curvature. The system can include a curing section configured to cure the coating, and can further include a web stretching section, which can be located proximate the curing section and can be substantially coincident with the curing section, such that the web is stretched while the coating is cured.
79 Citations
25 Claims
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1. A method for reducing strain-induced curl in a multi-layer web, the method comprising:
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providing a coated web, the coated web including a coating applied to a web of indeterminate length, the coating being characterized by at least partially shrinking when cured; curing the coating to form a multi-layer web, the multi-layer web including a strain induced by curing the coating; and stretching the web during curing of the coating, wherein stretching the web substantially cancels the strain induced by curing such that the resulting multi-layer web is substantially flat. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for producing a multi-layer web having a desired curvature, the method comprising:
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providing a coated web, the coated web including a coating applied to a web of indeterminate length; curing the coating to form a multi-layer web, the multi-layer web including a strain induced by curing the coating; and stretching the web during curing of the coating to induce an opposing strain in the web that at least partially counteracts the strain induced by curing, such that the resulting multi-layer web has a desired curvature. - View Dependent Claims (14, 15, 16)
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17. A light-redirecting film having a thickness of less than about 300 μ
- m and a curvature of less than about 0.1 m−
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- m and a curvature of less than about 0.1 m−
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18. A web handling system for producing a multi-layer web having a desired curvature, the web handling system comprising:
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a curing section configured to cure a coating applied to a web of indeterminate length to form a multi-layer web; and a web stretching section configured to stretch the web to induce a strain in the web, the web stretching section being proximate the curing section and substantially coincident with the curing section, such that the web is stretched while the coating is cured. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification