El procés de filatura de fusió de fil de Spandex
Dry spinning is the most traditional and common way of producing spandex. However, one of the major drawbacks of this method is the heavy investment required in construction of a commercial-scale production plant of, for example, 3000 to 5000 tons per year. At a 40-denier average, the overall investment is in the range of US$ 40 million to US$ 50 million which is quite high. Moreover, dry spinning also involves dealing with a toxic solvent recovery process and, in the dry process, the solvent remain in the final yarn. In the melt spinning method, no solvent is involved.
Melt Spinning: A competitive New Process
The melt-spinning process used for production of synthetic fibers such as polyamides, polyester and others is a well-established and long-existing technology in the industry.
In recent years, very low-cost melt-spinning equipment has been developed and is offered today in Asia for a price that is 20% of that of a dry plant of equivalent production capacity. This new process attracted many newcomers into the spandex production field.
In addition, recent developments brought more adequate TPU polymers and the introduction of pre-polymer into the melt stream of TPU to improve the elastic characteristics of the produced yarns. All these developments have further pushed this process forward.
For the above reasons, a lot of attention has been given to equipment, raw materials and technology to further improve the melt-spinning process for spandex.