Apparatus for producing thermoplastic yarns
US5076773A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1989 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | Nov 28, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01D13/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Continuous polypropylene multifilament yarns are made by melt spinning and stretching in an integral process; a sufficient number of filaments for forming at least 8 continuous filament yarns each consisting of at least 10 filaments are melt spun through a spinneret (11) at a speed of at least 400 m/min into a vertical air quenching zone or shaft (12) for solidification; the filaments are arranged to form a substantially planar array of parallel and mutually distanced yarn strands; then, the filaments are stretched to achieve substantial orientation by passing the yarn strands, while maintaining them in the array, over peripheral surface portions of a sequence of rotating cylinders (141, 142, 143, 144) having parallel axes of rotation, each strand (S) passing over surface portions along a discrete path which is substantially defined by a plane intersecting perpendicularly with the parallel axes of the cylinders; each strand is in frictional contact with the peripheral surface portions for a total contact path length of from 1000 to 6500 mm and at least 50%, preferably 75-100%, of the path length of frictional contact are provided on a total number of from 2 to 6 and preferably 4 la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.