Reifenhäuser Gmbh & Co. Maschinenfabrik

Bergwerksverband Gmbh

Didier Engineering Gmbh

Rolf H Joest

Hermann Balk

Bernd Kunze

Hans Georg Geus

Herbert Schulz

Ingo Romey

Rudolf Geier

Wilhelm Wullscheidt

A process for producing a web fleece of thermoplastic polymer filaments. Filaments of thermoplastic polymer are spun from a spinneret to form a curtain passing through a cooling chamber and a stretching channel. The volume rate of flow of the thermoplastic polymer from the spinneret, the volume rate of flow of air, the velocity of the air and the temperature of the air in the cooling chamber and stretching channel are so controlled that individual filaments of the curtain have filament diameters less than .mu.m and a degree of crystallinity less than 45%. The filaments of the curtain are collected on a continuously moving sieve belt in a mat whose crossing points fuse together. The mat is heated to a stretching temperature of 80.degree. to 150.degree. C. and stretched axially by 100 to 400%. The biaxially stretched mat is heated to a temperature above that of the stretching temperature to thermofix the web.

Process for producing a web of thermoplastic polymer filaments

A melt-blowing head is used to produce long thermoplastic filaments which are collected on a sieve belt and form crossing welds at cross-over points. The resulting mat may be calendered and is composed of filaments having a diameter of less than 100 .mu.m and a degree of crystallinity which is less than 45%. The mat is heated to a stretching temperature of 80 to 150.degree. C. and is then biaxially stretched by 100 to 400% before being thermally fixed at a higher temperature. The result is a nonwoven web which can have a greater strength for a given area weight or a reduced area weight for a given strength than earlier systems.

Method of making a fleece or mat of thermoplastic polymer filaments

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Duisburg, Germany

Rolf H Joest