The tight point of the elastic yarn refers to the phenomenon that the process conditions are improperly selected during the bombing process, causing the twist unbalance to produce necking or untwisting. As the polypropylene rigid, tight point is easy to produce, the factory in the provisions of the quality standards of polypropylene stretch yarn, the focus of the range are made specific instructions.

In addition to the twist of the original wire is too high, or improper selection of raw silk oil and other factors, there are still in the bombing process temperature, feed rate, the twists and turns of the three main factors will cause a tight increase.