Crosslaminate of oriented films and methods and apparatus for manufacturing same
OwnerOle-Bendt Rasmusseninventor
Life of this patent
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Abstract
A crosslaminate is formed from two oriented plies of thermoplastic polymer material, arranged so that their orientation directions cross one another, the plies being heat sealed together. Each ply is semi-fibrillated, that is consist of linear thin regions of biaxially oriented material and thicker linear bosses between the thinner regions. The webs are sealed primarily through bonds formed at the intersection of the bosses (thicker regions). The array of bosses has a division less than 2 mm. The laminate has improved aesthetic and strength properties. A method for forming the crosslaminate involves segmental stretching of the material to form the thinner regions, and apparatus comprising intermeshing grooved stretching rollers having sharp-edged crests is described.
Claims31
A crosslaminate comprising at least two oriented plies A and B, each comprising a thermoplastic polymer material, each biaxially oriented with one direction dominating and in which the ply A is heat sealed to the ply B through one or more lamination layers to form either (1) a weak bonding between the plies all over, or (2) a pattern of bonding including alternating bonding regions and non bonding regions or alternating strong bonding regions and weak bonding regions, and whereby the ply A and the ply B each comprises an array of linear bosses distributed over a film surface with a division no larger than about 2 mm, integrally connected by thinner linear webs (4) which each by volume is less than 50% of the average of the two adjacent bosses, and delineations between the bosses and adjacent thinner webs that comprise locations where a ply thickness is an average between a thickest part of the boss and a thinnest part of the web, and whereby a main cross-sectional portion of each boss is uniaxially oriented sufficiently to achieve a dominating direction of orientation of the ply A, while the thinner webs are biaxially oriented, wherein even distribution over an area of the laminate at least 50% of the areas of the thinner linear webs in the ply A and in the ply B are non bonded or are weakly bonded such that a majority of each boss to boss bond, is at least as strong as a strongest bond of an immediate adjacent thin web to thin web bonds as determined by peeling at room temperature.
A crosslaminate comprising:
- at least two oriented plies A and B, each comprising:
- a thermoplastic polymer material, each biaxially oriented with one direction dominating,
- an array of linear bosses distributed over a film surface having a division no larger than about 2 mm,
- thinner linear webs integrally connecting the bosses and having a volume less than 50% of an average of two adjacent bosses, and
- delineations between bosses and adjacent thinner webs comprise locations where a ply thickness is an average of a thickest part of the bosses and a thinnest part of the thinner webs,
- where a main cross-sectional portion of each boss is sufficiently uniaxially oriented to achieve a dominating direction of orientation of the ply A, while the thinner webs are biaxially oriented,
- where the ply A is heat sealed to the ply B through one or more lamination layers to form a bonding system where the thinner webs are substantially non-bonded all over, and the bosses are substantially bonded all over and where boss to boss bonds are stronger within regions comprising a plurality of bosses and thinner webs, than boss to boss bonds outside these regions, and
- where the thinner webs are evenly distributed over an area of the laminate.
A crosslaminate comprising:
- at least two oriented plies A and B, each comprising:
- a thermoplastic polymer material, each biaxially oriented with one direction dominating,
- an array of linear X bosses and Y bosses distributed over a film surface having a division no larger than about 2 mm between pairs of bosses,
- thinner linear webs integrally connecting the X bosses the Y bosses and having a volume less than 50% of an average of two adjacent bosses, and
- delineations between bosses and adjacent thinner webs comprise locations where a ply thickness is an average between a thickest part of the bosses and a thinnest part of the webs,
- where a main cross-sectional portion of each boss is sufficiently uniaxially oriented to achieve a dominating direction of orientation of the ply A, while the thinner webs are biaxially oriented,
- where the X bosses are thicker than the Y bosses,
- where the ply A is heat sealed to the ply B through one or more lamination layers to form a bonding system comprising only boss to boss bonding and the boss to boss bonds are stronger than the bonding between adjacent thinner webs, where the boss to boss bonding includes either only X boss to X boss bonds or the boss X to boss X bonds are stronger than Y boss to Y boss bonds, and
- where the thinner webs are evenly distributed over an area of the laminate and at least 50% of the areas of the thinner webs in the ply A and in the ply B are unbonded or are weakly bonded.
A crosslaminate comprising:
- at least two oriented plies A and B, each comprising:
- a thermoplastic polymer material, each biaxially oriented with one direction dominating,
- an array of linear bosses distributed over a film surface having a division no larger than about 2 mm,
- thinner linear webs integrally connecting the bosses and having a volume less than 50% of an average of two adjacent bosses, and
- delineations between the bosses and adjacent thinner webs comprise locations where a ply thickness is an average between a thickest part of the bosses and a thinnest part of the webs, and
- where a main cross-sectional portion of each boss is sufficiently uniaxially oriented to achieve a dominating direction of orientation of the ply A, while the thinner webs are biaxially oriented,
- where the ply A is heat sealed to the ply B through one or more lamination layers to form (1) a weak bonding all over or (2) a pattern of bonding including alternating bonding regions and unbonded regions or alternating strong bonding regions and weak bonding regions, where the unbonded regions include slacks, where an extent of the slacks is limited such that when viewed in a section perpendicular to an extension of the bosses and the webs, a width of the slacks, measured along the actual film surface, is at most 0.5 mm larger than a direct distance between boundaries of the slacks, and
- where the webs are evenly distributed over an area of the laminate and at least 50% of the areas of the thinner linear webs in the ply A and in the ply B are unbonded or are weakly bonded.
Dependencies are inferred from the claim text.