| With the growth of people’s environmental consciousness, the requirements for underwear is not onlybeautiful, healthy, but a perfect fit with human skin. The underwear which can show the beauty of the humanbody perfectly is more and more popular. Underwear is rely on seam to prevent from raveling, but its comfortand aesthetics are at a discount. For dry spandex being widely used, its process is high energy consumption,high cost. And its spinning solvent DMF has side effects on the environment. Green—melt spinning spandex isstudied and used. Dry spandex is applied to improve flexibility of underwear, however, its conformalperformance needs to be increased. All underwear should be carried out seam to prevent raveling which affectthe beauty of overall wearing shape and appearance. The application of melt-spinning spandex to makehigh-end applications without seam and none raveling underwear became a fashion darling.This project starts exploring the properties of melt-spinning spandex to study its fabric which has theadvantages of randomly cut, no seam and none-run properties. The microstructure, mechanical properties ofmelt-spinning spandex, as well as its heat setting conditions, mechanical properties and washing performanceof fabrics are compared with dry spinning spandex. Specific contents are as follows:1. According to scanning electron microscopy and DSC test of melt-spinning spandex, the cross-sectionaland longitudinal structure are realized, as well as the glass transition temperature and melting temperature aredefined.2. Study adhesion of nylon with melt spinning spandex and dry spandex respectively after heat setting.Choose time-temperature heat setting good combination combining DSC test results.3. Test and analyze elongation at break and elastic recovery properties of melt spinning spandex after heatsetting, study how different heat setting conditions affect its mechanical properties.4. Compare and analyze bursting strength and elastic recovery of dry and melt-spinning spandex fabricafter9groups heat setting conditions.5. Test washing performance of dry and melt-spinning spandex fabric after heat setting. Study howwashing times impact on their ravel properties.Through a series of research, testing and analysis obtained: melt-spinning spandex is single yarn, glass transition temperature is about54℃, the melting temperature is about144℃, cracking temperature is240℃.Heat setting conditions for melt-spinning spandex and nylon: setting temperature is150℃-170℃, setting timeis30s-60s. Low heat temperature requires long heat time, high heat temperature requires short heat time, thespecific setting conditions needs further experiments. After150℃and160℃heat setting, the longer the heattime, the bigger the intensity and strength of melt-spinning spandex. The maximum breaking strength occurs at160℃90s. After170℃heat setting, strength of melt-spinning spandex gradually decrease and decreasedrapidly after30s. Elastic resilience of dry spandex is higher than melt spinning spandex. Elastic recovery andstress relaxation rate of melt spinning spandex has decreased in varying degrees after heat setting. Elasticrecovery rate of melt spinning spandex is94.90%at160℃90s heat condition which keep the best. Burstingstrength of melt spinning spandex fabric changes little after heat treatment which is bigger than untreatedfabric. Under each setting condition, peak of bursting strength is160℃.For melt spinning spandex fabric,using150℃,160℃,170℃heat setting temperature,0℃and90℃cutting, after10times washing, theincrease of setting time, the better the none-run effect. The none-run effect of160℃60s and160℃90s heattreatment is significantly better than160℃30s. There is not ravel at170℃30s heat treatment, burrs severely at170℃60s. At three setting temperatures,0℃burr situation is better than90℃. After washing20times,30times,40times, the ravel and burr phenomenon after150℃and160℃heat treatment almost the same withwashing10times. However, after170℃30s,60s heat setting fabric, its edge raveling phenomenon occurs, andburrs serious.Test and analysis of this project can provide a theoretical reference for the practical application. It has aimportant significance for producing lingerie and high-end products. |
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