Spun non-woven fabrics with high dimensional stability, and processes for their production
AssigneeFirma Carl Freudenberg
InventorLudwig Hartmann
Life of this patent
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Abstract
Non-woven fabrics made from spun, synthetic polymer filaments and composed of several superposed layers of interbonded monofilaments and multifilament strands deposited in a tangled form; at least segments of the individual filaments of the multifilament strands being disposed parallel to one another with total or partial bonding together of the parallel filaments, and the individual filaments and the multifilament strands being bonded together at least at the points of their random crossings.
Claims19
A non-woven fabric comprising a plurality of superimposed layers of essentially endless uncrimped filaments in an interconnected, tangled relationship, deposited laminarly without the formation of arcs, said layers of filaments comprising both single filaments and filament groups;
- wherein said filament groups are multifilament strands comprising individual filaments which are disposed, at least at certain segments thereof, parallel to one another, and which individual filaments of said groups have been drawn and cured to a non-tacky state to prevent autogenous bonding;
- and wherein the parallel filaments within the filament groups and the single filaments are bonded together using binders comprising dispersions or powders of polymers or copolymers.
A non-woven fabric roofing sheet or road construction carrier material saturated with bitumen comprising a plurality of superimposed layers of essentially endless, uncrimped filaments in an interconnected, tangled relationship deposited laminarly without the formation of arcs;
- said layers of filaments comprising both single filaments and filament groups;
- wherein said filament groups are multifilament strands comprising individual filaments which are disposed, at least at certain segments thereof, parallel to one another, and which individual filaments thereof have been drawn and cured to a non-tacky state to prevent autogenous bonding;
- and wherein the parallel filaments within the filament groups and the single filaments are bonded together using binders comprising dispersions or powders of polymers or copolymers.
A process for the production of a non-woven fabric comprising a plurality of superimposed layers of essentially endless, uncrimped filaments, laminarly deposited, in an interconnected, tangled relationship, characterized by both single filaments and filament groups, comprising:
- (a) spinning individual filaments from a multiplicity of spinnerets;
- (b) drawing the spun, individual filaments aerodynamically in a moving gas stream;
- (c) curing the drawn individual filaments to a non-tacky state by cooling;
- (d) laying down a portion of the cured filaments as essentially parallel filament groups;
- while simultaneously
- (e) laying down the portion of cured filaments not laid down as parallel filament groups to form a web comprising both filament groups and single filaments;
- and
- (f) bonding the parallel groups of filaments and the individual filaments at their points of random crossing using binders comprising dispersions or powders of polymers or copolymers.
Dependencies are inferred from the claim text.