Twin roll box
Twinrollbox is a unit for texturing yarns and belongs to the family of stuffer box processes . With this unit, yarns can be deformed and crimped. A subsequent heatsetting process then permanently fixes this shape in the yarn.
application
Similar to the texturing of synthetic fiber filaments, attempts are also made to achieve a similar effect with spun, twisted or cabled yarns. But in contrast to conventional texturing processes, in which the main aim is to improve the fiber properties, when texturing yarns, the focus is primarily on the visual appearance. These yarns are used especially in the carpet industry , where they give the carpet a loose appearance thanks to the crimped structure. Many variations on carpet surfaces can be produced by combining different pile heights, yarn twists, materials and crimp shapes. The best-known representatives of these carpets are the Frieze carpet and the Shaggy carpet .
History
The stuffer box method in industrial use has been known for decades. The stuffer box method began with the texturing of yarn filaments. A large number of variations of this technique were in use. Over the years, however, this procedure became less and less important. Processes such as flat wire texturing or air-blow texturing have become more and more popular. This technique experienced a renaissance in the carpet industry after the frieze and shaggy carpets became fashionable. This process was ideally suited to give the carpet yarns a texture (crimp).
functionality
Cabled or twisted yarns are drawn into the first compression chamber of the Twinrollbox in a band of four, eight, 24 or 36 threads with the help of two feed rollers. The peripheral speed of these feed rollers also determines the production speed. In industrial use today, thread speeds of up to 650 m / min are achieved (depending on the thread). A second pair of rollers, designed as fan rollers, runs slower in a controlled manner. Due to the reduced speed, the fed-in yarn accumulates and is deformed. By changing the speed of the fan roller pair, the dynamic pressure can also be varied indirectly. This dynamic pressure variation allows the most varied of characters of Frieze yarns, textures and crimps to be produced. Another stuffer box after the fan roller pair, which can also be fed with steam, provides an additional design option for the yarns. For yarns with little twist or no twist at all, the twin roll box can also be flushed with a transport air, which significantly improves the running stability of these difficult yarns.
Thermosetting
The texturing , the crimping of the yarns, is not yet a permanent shape after leaving the stuffer box. This is due to the properties of the polymers. Therefore, after the texturing of yarns, a so-called heatsetting process must follow, through which the texturing is permanently fixed.
literature
- Celanese Acetate LLC (Ed.): Complete Textile Glossary. 2001, p. 29 ( PDF )
- Federal Institute for Vocational Education and Training, Berlin (Ed.): Assessment features of textile fibers. Volume 1–4, In: Course for Vocational Education. W.Bertelsmann Verlag KG, Bielefeld 1986.
- Franz Fourné: Synthetic fibers: production, machines and apparatus, properties. Plant design, machine design and operation manual . Hanser reference book, 1995, ISBN 3-446-16058-2 .
- Hans-J. Koslowski: Chemical fiber lexicon: terms - numbers - trade names . Deutscher Fachverlag, 2008, ISBN 3-87150-876-4 .
- Hanʼguk Munye Haksul Chŏjakkwŏn Hyŏphoe: Dictionary of fiber & textile technology. 7th edition. KoSa, Charlotte NC 1999, ISBN 978-0-9670071-0-6 .