The rapier weaving machine is a kind of shuttleless loom. It is a common loom for weaving small and medium-sized batches of pattern fabrics with frequent variety changes. During the weft insertion process of the rapier weaving machine, the weft is always actively controlled by the rapier, resulting in fewer weft insertion errors and high reliability. In the production process, the high-speed weft insertion of the rapier weaving machine, the consumption of the rapier and the rapier belt accounts for more than half of the total material consumption of the rapier weaving machine. So how to effectively avoid the wear of the rapier is very important to save production costs. In addition, once the rapier is worn, it will lead to the failure of weft insertion, and even cause a large number of warp yarn breaks in severe cases, affecting the quality of the cloth surface.
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1. Reasons for wear and tear
It is found in production that most of the rapier damage is caused by the collision between the weft feeding rapier and the weft receiving rapier. This situation is due to the gap formed by the long-term wear of the transmission device and the rapier belt, which leads to the dislocation of the rapier.
The wear of the rapier head of the rapier weaving machine has a lot to do with the variety of the weaving. For fabrics with coarse yarn number and high warp density, the rapier wear is more serious and the service life is short. The chemical fiber product rapier has a shorter service life, because the rapier head reciprocates on the chemical fiber warp to generate heat and generate static electricity, which condense a layer of hard material at the bottom of the rapier and it’s easy to hang up the warp yarn.
The sizing composition used in warp sizing also has a great influence on the wear degree of the rapier, and different sizing components also have different effects on the wear of the rapier head.
The process structure of the rapier weaving machine also has a certain relationship with the wear of the rapier, especially the higher the back beam and the greater the warp tension of the bottom layer are, the more serious the wear of the rapier is. Because the tension of the lower warp yarn is large, when the shed is gradually closed, the lower warp yarn lifts up to increase the lifting force of the supporting rapier accordingly, and the greater extrusion friction force on the guide hook leads to the greater wear on the rapier.
2. How to prevent wear?
The tightness of the time between the rapier weft insertion movement and the warp opening movement directly affects the wear of the rapier. If the warp opening time is too early, the weft feeding rapier has less contact with the warp yarn, and the warp yarn will be in more contact when the sword is withdrawn, so the rapier and the warp are rubbed and squeezed more. Similarly, if the warp opening time lags, the contact between the retracting sword and the warp will be less, but the weft-feeding rapier and the warp have more contact, so the friction and extrusion of the rapier and the warp will be more as well.
Choose a slurry that wears less to the rapier, which can greatly extend the life of the rapier. At the same time, it is of great significance to further study the coating technology of the rapier to enhance the wear resistance on the surface of the rapier. It plays an important role of prolonging the life of the rapier.
In the structure of the loom, the smaller the height of the back beam was, the rapier would suffer less wear. But it is worth noting that the proper elevation of the back beam is beneficial to improve the quality of the cloth surface, so a reasonable height of the back beam should be determined so that the weaving can be carried out smoothly.
The coating quality of the rapier is of great significance. When the rapier head enters and exits the shed formed by the warp yarns at high speed, the warp yarns generate alternating compressive stress on the surface of the rapier head, which causes the coating to be worn and peeled off. The peeled debris becomes abrasive particles with high hardness, which causes abrasive wear to the rapier under the action of the warp yarn. Over time, a height difference between the substrate and the coating is formed, resulting in the emergence of a cutting edge, which causes the warp yarn to be cut and the machine stops.