For many years attempts have been made by the industry experts to produce an elastic spandex yarn using a similar process by melt spinning TPU polymers.
We all know that 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. The same is true for constructing a wet-process plant. Moreover dry and wet spinning also involve dealing with a toxic solvent recovery process and, in the case of the dry process, traces of the solvent remain in the final yarn produced. In the melt spinning method, no solvent is involved.
The preparation process for polymer in both dry and wet spinning start by making the pre-polymer, the same used in melt spinning, and sometimes called a crosslinker. Wet-process plants are only economical in producing coarser yarns of 400 denier and above, due to the limited underwater spinning speeds of a maximum of 200 meters/m