Film structures and methods of making film structures
Assignee3M Innovative Properties Company
InventorsRonald Wayne Ausen, Sundaravel Damodaran, Hak-Rhim Han, David Wayne Hegdahl
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Abstract
A method of making a three-dimensional film structure having controllable contact properties comprises making separable surface elements on a top portion of a film structure and stretching the film structure to separate the separable surface elements, thereby obtaining a desired surface structure which delivers a certain contact property such as a pressure sensitive adhesive property. The separable surface elements are provided using a cut film surface, a stemmed film, or a layer of particles.
Claims21
A method of forming and applying a film structure having controllable surface contact properties comprising:
- providing a multilayer film structure which has first and second major surfaces and which includes an operating agent therein, the operating agent being spaced from the first major surface of the fun structure by a top portion of the film structure, the top portion being defined by predetermined separable surface elements, and the first major surface of the film structure being defined by a plane across separable surface elements;
- wherein the film structure includes a top film layer, wherein the top film layer includes the separable surface elements formed by at least partially cutting the top film layer
- inelastically stretching the multilayer film structure to separate the separable surface elements across the first major surface of the film structure and to increase the exposure of the operating agent through spacings between adjacent separated separable surface elements;
- applying the first major surface of the film structure to a surface of a substrate;
- and
- applying pressure to the second major surface of the film such that the operating agent contacts the structure surface of the substrate.
A method of forming a film structure comprising:
- extruding a planar film structure which has a first major surface, a second major surface, and a top portion formed by extrusion under the first major surface;
- cutting the extruded top portion of the film structure such that the top portion defines a plurality of separable surface elements where the second major surface is uncut;
- and
- stretching the film structure in the plain of the film at a stretch ratio of at least 1:1.05 to separate the separable surface elements across the first major surface of the film structure and to increase the exposure of an intermediate surface of the film structure through spacings between adjacent separated separable surface elements wherein when the stretch force is removed, the separated surface elements do not rejoin to their original position before stretching of the film structure and where the separated surface elements are on a continuous film structure formed by the film structure having the uncut second major surface.
Dependencies are inferred from the claim text.