Method of producing latent elastic, cross-direction-oriented films
AssigneeKimberly-Clark Worldwide, Inc.
InventorsLavada Campbell Boggs, Hannong Rhim, William Bela Haffner
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Abstract
A blown film process for producing low gauge, latent elastic films with high cross-direction orientation includes preferentially regulating the temperature gradient of the film along the expansion length. The regulation of temperature along the bubble profile allows more effective “down gauging” of the film and improved melt strength of the hot film. The choice of raw materials is an important element in producing cross-direction-oriented, low gauge, latent elastic films. The method of this invention can be carried out as either a multiple-bubble process or a single-bubble process.
Claims32
A method of producing a latent elastic, cross-direction-oriented film, comprising the steps of:
- extruding a thermoplastic elastomer, wherein the thermoplastic elastomer comprises between about 55% and 90% elastomeric resin and between about 10% and 45% polyethylene;
- blowing the extruded thermoplastic elastomer to form a first blown bubble;
- stretch-thinning the thermoplastic elastomer while blowing the thermoplastic elastomer;
- simultaneously cooling and collapsing the first blown bubble;
- heating and inflating the stretch-thinned thermoplastic elastomer to form a second blown bubble, thereby orienting the thermoplastic elastomer in a cross direction while heating and inflating the thermoplastic elastomer;
- and
- simultaneously cooling, collapsing, and winding the second blown bubble, thereby forming a latent elastic, cross-direction-oriented film.
A method of producing a latent elastic, cross-direction-oriented film, comprising the steps of:
- extruding a thermoplastic elastomer, wherein the thermoplastic elastomer comprises between about 55% and 90% elastomeric resin and between about 10% and 45% polyethylene;
- blowing the extruded thermoplastic elastomer to form a single blown bubble;
- stretch-thinning the thermoplastic elastomer while in the form of the single blown bubble, thereby orienting the thermoplastic elastomer in a cross direction;
- cooling the blown bubble;
- and
- collapsing the blown bubble.
A method of producing a latent elastic, cross-direction-oriented film, comprising the steps of:
- providing a thermoplastic elastomer comprising between about 55% and 90% elastomeric resin and between about 10% and 45% polyethylene;
- extruding the thermoplastic elastomer,
- blowing the extruded thermoplastic elastomer to form a blown bubble;
- stretch-thinning the thermoplastic elastomer, thereby orienting the thermoplastic elastomer in a cross direction;
- cooling the blown bubble;
- and
- collapsing the blown bubble, thereby producing a film that has a latent set of at least 50%, a tension set of less than about 20%, shrinkage of at least 50%, a draw ratio of at least 10, and a tensile force of at least 30.
Dependencies are inferred from the claim text.