Weft breakage of parts of water jet looms is mainly because hydrophilic fibers contain more polar groups and have strong hygroscopicity, and the strength decreases after absorbing moisture, especially for viscose yarn, the strength decreases by about 50% after absorbing moisture. Weft breaks will occur frequently.
There are three main reasons for the overlapping of weft and insufficient weft injection of water jet loom accessories: due to the high amount of yarn hairiness, the weft yarns are easy to stick to each other during weft storage, and the ordinary mechanical weft storage system is easy to entangle during weft insertion, which makes the weft unwound. difficulty. Due to the strong hygroscopicity of hydrophilic fibers, the self-weight increases significantly after absorbing water, and the flight resistance increases, resulting in insufficient weft injection.
In addition, the weft storage system of the water jet loom accessories controls the length of each weft by replacing the length measuring wheel, and the pre-wound length of each weft storage on the weft feeder can only reach 3/4 of the length of each weft, and 1/4 of the length is directly pulled out from the weft bobbin by the inertia of weft insertion. During the whole flight process of the weft, the first 3/4 is in a free flight state, and the rear 1/4 is in a restricted flight state. These two states The rate of decay is significantly different.
