Quick answer: Nylon spandex (nylon elastane, polyamide elastane) needs protection from three things: heat, long sun exposure and chlorine. Keep the iron below 140°C for nylon; spandex is safe to iron below 150°C, so a blend should stay under 140°C. Dry it in the shade, skip chlorine bleach, and rinse swimwear in clean water soon after swimming.
Why does nylon spandex need careful washing?
Nylon spandex rarely fails from abrasion first; heat, light and chlorine are its weak points. Nylon (polyamide) is very hard-wearing: the China Cotton Textile Association's textile knowledge page says nylon's abrasion resistance is 10 times that of cotton. The same source notes that nylon's heat resistance and light resistance are both limited. Spandex gives the fabric its stretch and recovery, but its breaking strength is low, and long exposure to sunlight or chlorine bleach makes it fade. That is why nylon spandex leggings or swimsuits usually show trouble as stiffness, yellowing, fading or bagging after too much heat, sun or chlorine.
What ironing temperature is safe for nylon spandex?
Iron nylon spandex below 140°C, and skip ironing when you can. Nylon should be ironed below 140°C, and spandex is safe below 150°C. In a blend, the more heat-sensitive fiber sets the limit, so nylon spandex stays under 140°C. Iron dial settings differ by brand, so check the iron's manual, use the low or synthetic setting, press through a cloth, and test on a hidden inside area first.
Nylon spandex creases easily, because nylon deforms and wrinkles under small forces. Most close-fitting nylon spandex garments do not need ironing; hanging them up to relax is safer than pressing them flat with a hot iron.
| Fiber | Ironing limit | Source |
|---|---|---|
| Nylon | Below 140°C | China Cotton Textile Association |
| Spandex | Below 150°C (safe ironing) | Baidu Baike, spandex entry |
| Nylon spandex blend | Below 140°C, follow nylon | Lower of the two |
Can nylon spandex be dried in direct sun?
Do not leave nylon spandex in strong sun for long; dry it in a shaded, airy spot. Nylon has limited light resistance, and spandex fades with long sunlight exposure, with large differences between spandex types. Turning garments inside out and avoiding midday sun reduces exposure. For sun-protection clothing and outdoor sportswear that are worn in the sun anyway, check lightfastness when sourcing the fabric, and rely on lab reports for final results.
Related: How to check colorfastness on nylon elastane fabric
Related: How to choose sun protection fabric
How should swimwear be cared for after chlorinated water?
Rinse nylon spandex swimwear in clean water soon after swimming, and never wash it with chlorine bleach. Long exposure to chlorine bleach makes spandex fade, and pool water is usually chlorinated, so swimwear spandex sits in that environment every session. Rinse the suit thoroughly, wash it gently, and dry it in the shade without wringing it or leaving it in the sun.
For swimwear meant for frequent pool use, ask the fabric supplier directly about chlorine-resistant treatment and test results instead of judging by hand feel.
Related: Nylon spandex swimwear fabric buyer's guide
How should nylon spandex be washed day to day?
Wash nylon spandex gently in cold or lukewarm water, with no bleach and no hot tumble drying. Hand wash where possible; in a machine, use a laundry bag and a gentle cycle. Avoid chlorine bleach and high dryer heat, since nylon does not handle heat well. Keep nylon spandex away from zips, hook-and-loop fasteners and rough fabrics in the wash, because these can pull threads out of the smooth surface.
Related: Why nylon spandex snags and pills
Care at a glance: washing, drying and ironing
Every care step for nylon spandex comes down to avoiding heat, light and chlorine.
| Step | Nylon weakness | Spandex weakness | What to do |
|---|---|---|---|
| Washing | Deforms and creases under small forces | Low breaking strength | Cold or lukewarm water, hand wash or gentle cycle in a bag, no wringing |
| Bleaching | — | Fades with long chlorine bleach exposure | No chlorine bleach |
| Pool use | — | Chlorine makes spandex fade | Rinse soon after swimming; check chlorine resistance when sourcing |
| Drying | Limited light resistance | Fades with long sun exposure | Inside out, in the shade, avoid midday sun |
| Tumble drying | Limited heat resistance | — | No high heat |
| Ironing | Below 140°C | Below 150°C | Avoid if possible; low setting, press cloth, test first |
What are common care mistakes?
The usual mistake is treating nylon spandex like cotton and fixing problems with heat, sun or bleach. Ironing creases out on a hot setting can leave shiny or stiff marks, because nylon has limited heat resistance. Leaving garments in the sun all day to freshen them up fades the spandex. Bleaching yellowed light colors with chlorine bleach fades the spandex and weakens its stretch.
How should care shape fabric sourcing?
When sourcing nylon spandex, plan for how the finished garment will be washed and worn, and ask about heat, light and chlorine at the swatch stage. Ask about chlorine resistance for swimwear, lightfastness for sun-protection and outdoor styles, and recovery after repeated washing for lingerie and yogawear. The garment's care label should state ironing and bleach limits that match the fabric, which cuts returns from customers who damage garments in the wash.
At Maoxing Textile Dyeing, we have worked with nylon spandex at Zhongda, Guangzhou, for 15 years, and buyers often ask whether a fabric can be ironed or left in the sun. Our advice is to wash and dry your swatches a few times under real care conditions, check color, hand feel and recovery, and rely on lab reports for final results.
Related: How to choose nylon spandex fabric at Zhongda Textile Market
FAQ
1. Can nylon spandex go in the tumble dryer?
High heat is not recommended. Nylon has limited heat resistance, so hot drying can distort or stiffen the garment. Line drying in the shade works well.
2. Which iron setting matches 140°C?
Follow your iron's manual; usually the low or synthetic setting. Dial temperatures vary by brand, so press through a cloth and test on a hidden area first.
3. What happens if I don't rinse my swimsuit after the pool?
Chlorine makes the spandex fade, and over time color and stretch suffer. Rinse thoroughly in clean water soon after swimming and dry in the shade.
4. Is fading after sun exposure a quality problem?
Not necessarily; nylon has limited light resistance and spandex fades with long sun exposure, and the degree also depends on spandex type and dyeing. If a garment fades badly and quickly under normal wear and correct care, a lightfastness test can settle it.
Sources
- Nylon abrasion resistance is 10 times that of cotton; nylon deforms and creases under small forces; limited heat and light resistance; iron below 140°C. China Cotton Textile Association, textile knowledge, http://www.ccta.org.cn/fszz/fzzsxx/rs/202104/t20210429_4136415.html , checked 2026-10-26 (Maoxing source library, this week, items 3, 4, 5).
- Spandex has low breaking strength; fades with long exposure to sunlight or chlorine bleach, varying widely by spandex type; safe ironing below 150°C. Baidu Baike, spandex entry, https://baike.baidu.com/item/%E6%B0%A8%E7%BA%B6/2077532 , checked 2026-10-26 (Maoxing source library, this week, item 7).
Maoxing Textile Dyeing | nylon spandex weft-knitted fabrics Stall 16-18, North 5th Street, Zhongda Jiangnan Textile City, Haizhu District, Guangzhou, China WhatsApp: +86 159 1896 4057 Email: zhangzengwen@mail.gzmaoxing.com Web: https://gzmaoxing.com/en/ Open daily 09:00-19:00; please message before visiting.