Polymeric Film and Method of Making Same
Assignee3M Innovative Properties Company
InventorsStephen A. Johnson, William T. Fay, Atheen R. Johnson, Brian R. Peterson
Life of this patent
Estimating the term…
Abstract
A polymeric film has an orthogonal length, width and thickness. The polymeric film includes first and second substrates spaced apart along the thickness and a plurality of crumpled elements extending between the first and second substrates and along the length. The crumpled elements are substantially coextensive with the first and second substrates along the length and are spaced apart along the width.
Claims15
A polymeric film having an orthogonal length, width and thickness, the polymeric film comprising:
- first and second substrates spaced apart along the thickness;
- and
- a plurality of crumpled elements extending between the first and second substrates and along the length, the crumpled elements substantially coextensive with the first and second substrates along the length and spaced apart along the width.
An integrally formed polymeric film having an orthogonal length, width and thickness, the integrally formed polymeric film comprising first and second portions spaced apart along the thickness and a plurality of elements extending between the first and second portions along the length and spaced apart along the width to define a plurality of through channels extending substantially coextensively with the integrally formed polymeric film, at least one of the first and second portions being birefringent.
A method for making a polymeric film extending along a length direction of the polymeric film and having a width along a width direction of the polymeric film orthogonal to the length direction, the polymeric film defining a plurality of channels therein, the channels extending along the length direction and arranged along the width direction, the method comprising:
- extruding first and second resins through respective first and second pluralities of slots in a slot plate to form a molten stack of alternating respective first and second extended elements, each of the first and second pluralities of slots having a flow direction angled relative to a first plane defined by the length and width directions, the first and second extended elements extending along the length direction and being tilted in a second plane orthogonal to the length direction;
- extruding first and second skin layers onto respective opposite first and second sides of the molten stack to form a molten film;
- compressing the molten film in at least a thickness direction orthogonal to the length and width directions;
- cooling the molten film to form a first film;
- and
- stretching the first film along at least the width direction to form the polymeric film.
Dependencies are inferred from the claim text.