Oriented multi-layer films having a different orientation distribution between layers
AssigneeW. R. Grace & Co., Cryovac Division
InventorHenry G. Schirmer
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Abstract
The invention comprises an oriented multi-layer film having a different orientation distribution between at least two layers and a novel process for forming oriented multi-layer films having a different orientation distribution between the layers. An important feature is the formation of a first tubular layer which is folded and fed into the interior of a second tubular layer of smaller diameter. Upon inflation of the inner tubular layer of larger diameter to its maximum unstretched diameter the smaller diameter outer tubular layer will be stretched and will also be oriented if the stretching occurs while the temperature of the smaller diameter outer tubular layer is maintained within the orientation temperature range of that material.
Claims15
A seamless multi-layer film comprising:
- an outer layer having a melting point and an orientation temperature range;
- an inner layer having a melting point and an orientation temperature range;
- wherein the orientation temperature range of said inner layer is substantially higher than the orientation temperature range of said outer layer and the melting point of said inner layer is substantially higher than both the melting point and the orientation temperature range of said outer layer;
- and with
- said inner and outer layers having a different orientation distribution.
Dependencies are inferred from the claim text.