Boiling water shrinkage test
(1) Take four spandex samples, remove the surface layer, and then take three sections of 10cm in length and mark the distance with a colored pen.
(2) Put the sample in boiling water (100°C) for 10 minutes, then take it out and hang it to dry at room temperature. After 5 minutes, measure its shrinkage length.
(3) Calculate the boiling water shrinkage rate based on the difference between before and after boiling water, and the standard rate is 10-15%.
Boiling water shrinkage (%)=(10cm-test length)/10×100%
Conclusion: The boiling water shrinkage rate exceeds 10-15%, indicating that the stability of spandex is poor.
Spandex elasticity test
(1) Take four spandex samples, remove the surface layer, and then take three sections of 10cm in length, and mark the distance with a colored pen.
(2) Join the head and tail of the sample, test it on a single yarn strength machine, and stretch it at a speed of 50 cm/min.
(3) First stretch the sample by 100%, 150%, 200%, 250%, 300% for 3 times, and then calculate its tensile stress (cn) and elastic recovery rate for the fourth time. Elastic recovery rate%=(10cm-test length)/10 X 100%.
Conclusion: Different products have different requirements for the elasticity of spandex. Some products require low elongation, high elasticity or high elongation, low elasticity or low elongation, low elasticity or high elongation and high elasticity for spandex, so different fabrics Kind to choose different suitable spandex. The standard rate is compared with other brands with 300% data to ensure that the quality of spandex used by the enterprise is consistent.

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