Method for producing improved polymeric films
AssigneeExxonMobil Oil Corporation
InventorRobert G. Peet
Life of this patent
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Abstract
A method for producing an improved coextruded polymeric film is disclosed. First, a base layer containing a polymeric matrix and at least one additional layer on at least one side of the base layer are coextruded. If the coextruded polymeric film is to be opaque, the base layer also contains at least one cavitating agent. Next, the coextruded multi-layer film is cooled. Finally, the coextruded multi-layer film is oriented in at least the machine direction (MD). At least the base layer of the coextruded polymeric film contains a fluoropolymer. The inclusion of the fluoropolymer in at least the base layer of the coextruded polymeric film provides a more even distribution of polymer flow through a die, which in turns leads to improved film gauge uniformity.
Claims19
A method for producing a coextruded, oriented opaque polymeric film comprising:
- (a) coextuding (i) a base layer comprising a polymeric matrix and at least one cavitating agent, (ii) at least one additional layer on a first side of the base layer, and (iii) at least one additional layer on a second side of the base layer;
- (b) cooling the coextruded multi-layer film;
- and then
- (c) orienting the film in at least the machine direction (MD);
- wherein at least said base layer contains a fluoropolymer.
A method for producing a coextruded, oriented polymeric film comprising:
- (a) coextruding (i) a base layer comprising a polymeric matrix, (ii) at least one additional layer on a first side of the base layer, and (iii) at least one additional layer on a second side of the base layer;
- (b) cooling the coextruded multi-layer film;
- and then
- (c) orienting the film in at least the machine direction (MD);
- wherein at least said base layer contains a fluoropolymer and said base layer does not contain a cavitating agent.
Dependencies are inferred from the claim text.