Method for the production of spontaneously crimping man-made fibres and filters comprising man-made fibres of this type

摘要

For the production of spontaneously crimping man-made chemical fibres, it is proposed to spin together two thermoplastic polymers of the same kind, of which one is modified with rubber and has an elastic entropy deformation behaviour. In contrast to the main patent (main application), according to which the filaments are spun as bicomponent fibres by means of a bicomponent nozzle suitable for this purpose, it is now proposed to disperse the polymers in one another before spinning and to spin them by means of a spinneret for homogeneous polymers which is of simple construction. A bicomponent structure of the filaments is obtained in which the base polymer essentially forms the continuous phase and the rubber-modified polymer is present in side-to-side arrangement and/or in the form of discrete inclusions. The dispersion is dependent on the number of mixing steps, preferably static mixers, in the melt channel and the regularities of a random distribution occur with respect to cross-sectional content and geometrical arrangement in the filaments. After drawing, the filaments develop their crimp spontaneously and are readily applicable as filter material for gases and vapours.