METHOD FOR MANUFACTURE OF NONWOVEN MATERIAL FROM TWISTED MULTICOMPONENT THREAD AND NONWOVEN MATERIAL Russian patent published in 2004 - IPC

FIELD: manufacture of nonwoven materials. SUBSTANCE: method involves extruding continuous multicomponent threads having section capable of twisting. Threads have first filament and second filament. First filament includes propylene polymer selected in the group consisting of polypropylenes with high melt flow rate, low polydispersity polypropylenes, amorphous polypropylenes, and elastomeric polypropylenes. Method further involves cooling threads and thinning by melting with the result that threads are spontaneously twisted after releasing of thinning force; settling onto forming surface for forming of nonwoven material. Second version of method involves same features as first version except that first component includes first propylene polymer and second component includes mixture of first propylene polymer and second propylene polymer selected in the group consisting of low polydispersity polypropylenes, amorphous polypropylenes, elastomeric polypropylenes and propylene copolymers. Nonwoven material is formed from spirally twisted threads. According to another method, it differs from the former method in that second component includes polyethylene elastomer, and in that thread thinning is carried out without heating and material is formed from spirally twisted threads. Contrary to the latter method, another method is characterized in that first component includes polypropylene with melt flow rate exceeding 50 g/10 min and in that second component includes polyethylene. Nonwoven material, produced by said first or second methods with the use of melting procedure by means of air flow having temperature of 38 C for thinning of threads, has nonwoven web of continuously twisted multicomponent threads including at least first and second components, where second component includes polypropylene elastomer. Another nonwoven material produced by first or second method, where threads are thinned by melting without heating procedure. EFFECT: improved quality of nonwoven twisted materials possessing required combination of properties, such as softness, resilience, flexibility, strength, bulkiness, density and/or complete homogeneity of web, and reduced production cost. 46 cl, 4 dwg, 10 ex