Spinning (polymers)

With melt spinning is meant the production of fibers from molten polymers are forced through one or more nozzles and wound on curlers. When using only one nozzle with mostly larger diameter results in a so-called monofilament, a multifilament with multiple nozzles. Common polymers for melt spinning process are polypropylene, polyester ( specifically PET = polyethylene terephthalate) and polyamide. It is also possible to mix several polymers in a filament in a defined geometry simultaneously while spinning what the Bikomponentenschmelzspinnverfahren will be used. Melt spinning is the most common and most productive method to produce fibers.

A stable melt spinning process requires a corresponding flow behavior of the molten polymer. The polymers used are constructed usually linear and may be present only in a certain molecular weight range. By Aufwicklen after exiting the die, the fiber is stretched, wherein the polymer chains are partially oriented in the fiber direction. The solidification of the polymer during cooling in the fiber form amorphous and crystalline portions. The ratio of amorphous and crystalline regions and the Kristallstrukruren formed depend strongly on the polymer and the withdrawal speed. With increasing withdrawal speed (typically in the range of 1000-6000 m / min), the orientation of the polymer chains improved. A distinction LOY (low oriented yarn ), POY (partially oriented yarn ) and HOY (high oriented yarn ).

On the other hand is understood to mean the melt spinning, a process for rapidly cooling from melt, wherein the melt is blown onto a rotating wheel. This is a faulty translation from the English, which refers to this process as "melt spinning". "spin " in this case but not " spin " " twist fibers together " but in the sense of " turn quickly " or " spin ". A better name of the method is therefore melt spinning: the solidified melt on the rotating wheel is spun away usually by the rapid rotation immediately.