اسپاندکس، لایکرا یا الاستان نوعی لیف مصنوعی است. که به دلیل خاصیت الاستیسیته ی خوبی که دارد بسیار مورد توجه است.. این لیف نوعی کوپلیمر است. که در سال توسط شیمیدانی به نام  Joseph Shivers در شرکت دوپانت (DuPont) کشف شد. صرف نظر از روش است.فاده شده برای تولید اسپاندکس، ساختار شیمیایی محصول نهایی یکسان خواهد بود اما ممکن است. الفاظ مختلفی که برای این پلیمر به کار میرود سبب سردرگمی مصرف کنندگان شود.

تمامی این روش ها در مرحله ی اول شامل اینترکشن میان مونومرها به منظور تولید پلیمر است.. زمانی که پلیمر تشکیل شد، طی فرآیندهای مختلف الیاف تشکیل میشوند. هم اکنون بیش از . درصد از الیاف اسپاندکس در دنیا به روش خشک محلول ریسی (solution dry spinning) تولید میشوند.

Consistent with SNIA technology, the production process for this product starting with the mixing of monomers as feedstock input to the reactors for polymer solution in Dimethylformamide (DMF) in the Chemical Area through to fiber production, drawing, finishing and packaging is continuous and that at each stage samplings and controls are conducted and finally the product is graded and released in accordance with the test results. Bright, dull and semi-dull products are normal products but colored, super-white and antibacterial products are customized. The product is packaged in bales weighing ± kg and then put in covered polypropylene jute and rod guards. The bales measure ** mm. - tons of the product can be transported in a -foot container. 

Our acrylic fibers are produced using monomer acrylonitrile as the major monomer (over %), methylacrylate or vinyl acetate as the second comonomer (less than %) and a third comonomer for dyability, by Solution Polymerization and Wet Spinning using SNIA technology. In both dull and semi-dull product, Titanium Dioxide (max .%) is used. Also, in the process of production, the fibers are submerged in finish (finish of about .%) prior to packing.

Consistent with SNIA technology, the production process for this product starting with the mixing of monomers as feedback input to the reactors for polymer solution in Dimethylformamide (DMF) in the Chemical Area through to fiber production, drawing, finishing and packaging is continuous and that at each stage samplings and controls are conducted and finally the product is graded and released in accordance with the test results. Bright, dull and semi-dull products are normal. The product is packaged in bales weighing ± kg and then put in covered polypropylene jute and rod guards. The bales measure ** mm. - tons of the product can be transported in a -foot container.