Ultra-low Temperature Easy-to-set Elastane

2025-03-18News 870

Reasons for recommendation

It can be set at ultra-low temperature with high efficiency. Lt can be interwoven with fibers with poor heat resistance, such as polypropylene fiber and polylactic acid fiber, broadening the application fields of elastane.

Preparative technique

Dry-spinning process: With polyether polyol and diisocyanate as raw

materials, and small molecule dihydric alcohol as chain extender, stepwise polymerization is used to produce polyurethane-urea solution. Subsequently, the low-melting point mother solution is mixed with polyurethane-urea solution to produce a polyurethane-urea spinning solution with high heat-setting efficiency at ultra-low temperature. Finally, the dry-spinning technology is used to produce the fiber.

Melt-spinning process: Polyhydric alcohols, diisocyanate, and chain

extender are preheated and undergo bottler for reaction and extrusion into chips. Then, the elastane chips are processed through melt spinning to produce the fiber. The solvent-free melt spinning process is adopted, which is more environmentally friendly and green.

Features of fibers and finished products

Filament:20~40D,20D, 30D, 40D, 70D

Properties of fibers and features of finished products

.Lower setting temperature, fulfilling the setting requirements of

120~130°C; significantly energy consumption reduction in weaving process.

·Fast rebound speed, fabric edges less prone to curling, smoother and

more beautiful, soft and comfortable.

·Resistant to chlorine, more uniform yarn levelness.

Performance indexes of ultra-low temperature easy-to-set elastane

Specifications	Breaking tenacity (cN/dtex)	Elongation at break (%)	300% elongation strength (cN/dtex)(%)	Elongation elastic recovery rate(%)	Dry-heat setting efficiency(%)	Wet-heat setting	Fabric shrinkage rate
20D	≥0.85	500±40	0.27±0.06	≥88.0	≥90	≥70	(Polypropylene fiber +ultra-low temperatureeasy-to-set elastane)5.0
30D	≥1.25	500±40	0.30±0.05	≥90.0	≥90	≥92	(Polylactic acid + ultra-low temperature easy-to-set elastane) 2.0

The downstream application guidance

During the setting process, it is necessary to consider the setting temperature for sensitive main yarn fiber to achieve the setting effect comparable to that of conventional elastane.

Weaving: The recommended drawing ratio for a double-sided 28G large circular knitting machine is≤ 2.6 times, while for a single-sided 28G large circular knitting machine, it is≤2.7 times. For wrap yarn, the recommended drawing ratio is 1.6~3.0 times.

Setting: The recommended setting temperature is120~130°C, and the period is50~80 seconds.

Dyeing: The recommended dyeing temperature is≤ 110℃ , and the suitable pH range of dyeing solution is 3~11.

Examples of downstream applications for ultra-low temperature easy-to-set elastane

Terminal field	Raw material ratio	Fiber specifications	Product features
Knitted fabric	71% polylactic acid fiber /29% ultra-low temperature easy-to-set elastane	30D semi-dull	Special ultra-low temperature easy-to-set elastane for polylactic acid fiber

Application of fibers

Clothing textiles:Sportswear\Socks\Swimsuit\Yoga clothes\

Q: What are the performance advantages and downstream application

benefits of ultra-low temperature easy-to-set elastane?

A: The setting temperature for ordinary elastane ranges between 190~205°C,whereas fibers such as polypropylene fiber and polylactic acid fiber need to be set at lower temperatures. The heat-setting temperature of ultra-low temperature easy-to-set elastane is significantly reduced that it can be set at 120~130℃ and dyed at 110℃ . This enables it to be interwoven with fibers that have low heat resistance, such as polypropylene fiber and polylactic acid fiber, making it widely used in fields such as sportswear, swimwear, and tights.