Abstract Bicomponent fibers, and webs made therefrom, are taught in which one component of the fibers is a crystallizable material. When a web of the fibers is heated in a mold above the temperature at which crystallization occurs, the fibers tend to be set in the position they are held in the mold. A preferred fiber comprises blown fibers comprising as one component amorphous, crystallizable polyethylene terephthalate, and as the other component polypropylene. A web of such fibers not only becomes formed into a shape-retaining form by crystallization during the molding process, but also can be further established in its shape-retaining character by heating the web above the softening point of the polypropylene, whereupon the fibers become bonded at their points of intersection.
A fibrous web comprising bicomponent fibers that individually comprise a first polymeric material extending longitudinally along the fiber through a first portion of the cross-sectional area of the fiber and a second polymeric material extending longitudinally along the fiber through a second portion of the cross-sectional area of the fiber; characterized in that the first polymeric material is amorphous but undergoes crystallization at a temperature less than the melting temperature of the second polymeric material, which causes the bicomponent fibers to retain the shape they assume during crystallization, whereby the web can be molded to a fibrous shape-retaining form.
Claim 2
Dependent Claim
99 words
A fibrous web comprising bicomponent fibers that individually comprise a first polymeric material extending longitudinally along the fiber through a first portion of the cross-sectional area of the fiber and a second polymeric material extending longitudinally along the fiber through a second portion of the cross-sectional area of the fiber; characterized in that the first polymeric material is amorphous but undergoes crystallization at a temperature less than the melting temperature of the second polymeric material, which causes the bicomponent fibers to retain the shape they assume during crystallization, whereby the web can be molded to a fibrous shape-retaining form.
Claim 3
Dependent Claim
32 words
A fibrous web of claim 1 in which the crystallization raises the melting temperature of the first polymeric material to a temperature higher than the melting temperature of the second polymeric material.
Claim 4
Dependent Claim
17 words
A fibrous web of claim 1 or 2 in which the first polymeric material comprises polyethylene terephthalate.
Claim 5
Dependent Claim
17 words
A fibrous web of claim 1, 2 or 3 in which the second polymeric material comprises polypropylene.
Claim 6
Dependent Claim
26 words
A fibrous web of any of claims 1-4 conformed to a non-planar shape and held in that shape by said crystallization of the first polymeric material.
Claim 7
Dependent Claim
27 words
A fibrous web of any of claims 1-5 in which the fibers are bonded by fusing of one of the polymeric materials at intersections of the fibers.
Claim 8
Dependent Claim
16 words
A fibrous web of any of claims 1-6 in which the bicomponent fibers comprise blown fibers.
Claim 9
Dependent Claim
20 words
A fibrous web of claim 7 in which the bicomponent blown fibers average no more than 10 micrometers in diameter.
Claim 10
Dependent Claim
18 words
A fibrous web of claims 7 or 8 in which staple fibers are dispersed with the blown fibers.
Claim 11
Dependent Claim
16 words
A fibrous web of any of claims 1-9 which includes fibers that carry an electric charge.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.