GB1285003A - Composite fibrid yarns and method of their manufacture - Google Patents

Abstract

1285003 Filaments with embedded fibrids E BOBKOWICZ and A J BOBKOWICZ 19 March 1970 [15 Sept 1969] 13232/70 Heading B5B [Also in Division D1] A yarn comprises a continuous filament of a synthetic organic polymeric material with fibrids embedded within the filament and consolidated therewith, the fibrids generally protruding outwardly from the filament in the form of filamentous units having an average length of from # to ¢ inch, a fineness of between 0À2 and 1 denier and a specific surface area above 2 m.<SP>2</SP>/g. In this way hairiness, a snarl yarn effect or a chenille effect is imparted to the yarn. A fibrid is defined as a continuous strand of interconnected segments of fine fibres and thin films forming an irregular three dimensional network of plexifilamentous and ribbon shaped components. The continuous filament may have a predetermined molecular orientation and the yarn may be in twisted condition. The yarn may be produced in a continuous manner by means of the apparatus shown in Fig. 8 of the drawings. In operation a curtain of filaments 10 is melt extruded downwards from the extrusion head 14 towards the nip of a pair of nip rolls 15, 16. Simultaneously a mat 17 of intertangled fibrids of synthetic organic polymeric material is supplied into a shredding, licker-in means 20 by means of feeding roller 18. The means 20 comprises a hollow rotatable cylinder 21 having sharp teeth 22 protruding from its peripheral surface which is perforated. The inside of the cylinder is provided with suction producing means 23 and air blowing means 24 within separate compartments. When the mat 17 is conveyed by the feeding roller 18 into the inlet aperture 26 of the casing 25 within which the cylinder is mounted it is sucked through the aperture 26 by the means 23 and gripped by the toothed surface of the roller 21. The mat 17 is thereby disintegrated into individual fibrids and simultaneously conveyed from inlet 26 to outlet 27 of the casing 25. At this point the individual fibrids are blown by the means 24 into the duct 28 leading towards a fibrid parallelizing and forwarding device 30 consisting of a perforated hollow cylinder 31 having a number of circumferential parallel grooves into which the fibrids are pulled by suction means 32 mounted within the cylinder and thereby substantially parallelized. The fibrids are then projected towards the nip of the rolls 15, 16 where they contact the filaments 10 which are still at a sufficiently high temperature to be soft and adhesive. The nip rolls 15, 16 are rotated at a peripheral speed higher than that of the cylinder 31, thus aiding the transportation of the fibrids in the form of loosely structured ribbons 41 towards the nip of the rolls 15, 16. If desired, additional filaments 10a which are solid and have been preformed and highly orientated may be introduced between the soft filaments 10 and passed through the nip of the rolls 15, 16. The fibrid carrying filament or yarn 12 may be collected in a wind up roll 33 to form a package 34 of zero twist yarn or may be twisted in the twisting device 43 before being wound up on the roll 33. The filament may be made of polyamides, polyesters, polyolefins, polyacrylonitrile, polyvinylidene chloride and rubber compounds, or phenol-formaldehyde or urea-formaldehyde resin. The fibrid units may be made of polyamides, polyesters, polyurethanes, polyureids, polyacrylonitrile, acrylonitrile copolymers, copolyamides, copolyesters, polythioesters, polysulphonamides, polysulphones, polyoxymethylene and their copolymers, plasticized vinyl polymers, block copolymers of polyester or polyether segments linked with aromatic diisocyanates, and plasticized polyvinyl chloride or polymethyl methacrylate and copolymers of butadiene with acrylonitrile or styrene.