Abstract: 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.

Abstract: Nonwoven spun-bond is produced by a stationary pressure apparatus in which the shaft below the spinneret has an inlet section followed by the downwardly converging intermediate section, a drawing section and a diffuser opening above the collecting belt through which air is drawn by a suction device. The process air velocity profile has an intersection point with the drawing value at the intermediate section and the distance between the intersection point and the spinneret is smaller than the distance between the intersection point and the bottom end of the drawing section.

Abstract: A spun-filament nonwoven web is deposited on a sieve belt from a spinning head producing a curtain of thermoplastic filaments which traverse a cooling chamber by drawing the filaments in a drawing nozzle separate from the cooling chamber and passing the filaments through a delivery unit and in the form of a jet pump, air flow through which is controlled at least in part by a suction blower below that sieve belt.