Apparatus for preparing fibrous web

Claim 2

Apparatus for use in preparing fibrous web from an extruded uniaxially oriented moving polymer film by cutting elongated slits in said film comprising a toothed roller and a presser roller positioned with their respective circumferential surfaces parallel and closely adjaceNt to and spaced apart from each other, means for rotating the toothed roller and presser roller substantially synchronously and in relatively opposite directions to each other at peripheral speeds about 1.5 to 20 times greater than the film speed, helical grooves formed in the circumferential surface of the said presser roller, helical rows of teeth extending radially from the circumferential surface of the said toothed roller, selected rows being positioned complementary and in mating relationships to respective selected complementary helical grooves, and said teeth penetrating radially into the said respective selected grooves as the toothed roller and presser roller rotate.

Claim 3

The apparatus of claim 1 wherein the working angles of the teeth are about 90* with the roller face, the helical rows of teeth are substantially equidistant and the distances between adjacent teeth in a row are substantially the same.

Claim 4

Apparatus for use in preparing fibrous web from an extruded uniaxially oriented moving polymer film by cutting elongated slits in said film comprising a cylindrical toothed roller and a cylindrical presser roller positioned with their respective circumferential surfaces parallel and closely adjacent to and spaced apart from each other, means for feeding said film between the toothed roller and presser roller at an angle such that the film contacts the circumferential surface of the presser roller before it contacts the toothed roller and is supported on the circumferential surface of the presser roller, means for rotating the toothed roller and presser roller in relatively opposite directions to each other and substantially synchronously at peripheral speeds about 1.5 to 20 times greater than the film speed, helical grooves formed in the circumferential surface of the said presser roller, helical rows of substantially equidistant teeth extending radially from the circumferential surface of the toothed roller and having working angles of about 90* with the roller face selected rows of teeth being positioned complementary to respective selected helical grooves, said selected rows meshing with said respective selected grooves as the toothed roller and presser roller rotate such that the distance between the edges of said respective grooves which support the unslit film and the tips of said teeth meshed in said respective grooves is less than the lateral off-set distance between the points of adjacent teeth in a row, means for withdrawing the film from between said toothed roller and said presser roller at an angle such that the film remains in contact with the circumferential surface of said presser roller until the teeth disengage the film and means for keeping the film under about 600 to about 3,000 psi tension while said film contacts the circumferential surface of the presser roller.

Claim 5

Apparatus for use in preparing fibrous web from an extruded uniaxially oriented moving polymer film by cutting elongated slits in said film comprising a cylindrical toothed roller and a cylindrical presser roller positioned with their respective circumferential surfaces parallel and closely adjacent to and spaced apart from each other, means for feeding said film between the toothed roller and presser roller at an angle such that the film contacts the circumferential surface of the presser roller before it contacts the toothed roller and is supported on the circumferential surface of the presser roller, means for rotating the toothed roller and presser roller in relatively opposite directions to each other and substantially synchronously at peripheral speeds about 1.5 to 20 times greater than the film speed, helical grooves formed in the circumferential surface of the said presser roller, helical rows of substantially equidistant teeth extending radially from the circumferential surface of the toothed roller and having working angles of about 90* with the roller face selected rows of teeth being positioned complementary to respective selected helical grooves, said selected rows meshing with said respective selected grooves as the toothed roller and presser roller rotate such that the distance between the edges of said respective grooves which support the unslit film and the tips of said teeth meshed in said respective grooves is less than the lateral off-set distance between the points of adjacent teeth in a row, means for withdrawing the film from between said toothed roller and said presser roller at an angle such that the film remains in contact with the circumferential surface of said presser roller until the teeth disengage the film and means for keeping the film under about 600 to about 3,000 psi tension while said film contacts the circumferential surface of the presser roller.