Technical Topic: How To Avoid The Wear Of Rapier-head And Rapier-Rod Belt

- Aug 28, 2017-

Rapier loom is a kind of shuttle-free Loom, which is a general weaving machine for weaving small and medium size and variety Chanchan. In the production process, rapier loom high-speed weft, rapier and rapier belt consumption of the Rapier loom machine material consumption of more than half. Therefore, how to effectively avoid the wear of rapier and rapier belt is very important to save production cost.
Damage to Wear
The rapier and Rapier belt are the key parts of the rapier loom to complete the weft-insertion task. In the process of weft insertion of rapier loom, the weft is always controlled actively by the Rapier head, which makes the error of weft insertion less and has high reliability. Once the sword head is worn, it will lead to the failure of weft insertion, which will cause the warp mass to break down and affect the quality of the cloth.
The loom runs 400 rpm, the daily Operation 20 Hour calculates, each day the sword head reciprocating up to 960,000 times, in the long run process the sword head inevitably wears. The most easily worn part of the head is the head, the flanks and the bottom. Once each weft, the sword head in the sword and exit the sword must be subject to warp, guide the sword Hook, take the sword plate and guide, etc. friction. When the Blades of the sword head are badly formed, it is easy to cause the end of the warp, and even the sword head is not controlled by the guide hook to jump out of the shuttle and form a large number of severed ends.
Wear reason
The production practice found that most of the damage of the rapier head is caused by the impact of the head of the weft-feeding and the contact of the Rapier head. This situation is due to the long time wear and tear of the driving device and the Rapier belt, which leads to the dislocation of the sword head. such as the GA749 Rapier loom, the rapier head is relatively lenient, its skeleton is made of plastic, so most of the damage is the head of the weft-feeding. Most of the sword head break occurs in the head of the stop yarn, grip the yarn part.
The wear of rapier loom is also closely related to the knitted varieties, and the wear of different varieties to the rapier head varies greatly. The yarn number coarse, the warp density large fabric, the sword head wears is quite serious, the service life is short. And the use of chemical fiber products sword Head is shorter, this is because the leader of the sword in the chemical fiber warp reciprocating friction heating, produce static electricity, so that the bottom of the sword to condense a layer of induration material, easy to hang up the warp.
The sizing effect of warp sizing also has a great influence on the wear degree of the head, and the different slurry compositions have different influence on the wear of the sword boss.
The process structure of rapier Loom is also related to the wear of the sword head, especially the higher the height of the rear beam, the greater the bottom warp tension, the more serious the wear of the rapier head. Because the lower warp tension is large, when the shuttle mouth gradually closed, the lower layer of the warp to lift the support on the head of the corresponding increase in the force of the sword Hook, the greater the extrusion friction, so the more wear on the head of the sword.
The transmission between the Rapier belt and the rapier wheel of the Rapier loom is a special belt drive: A rectangular hole is on the rapier belt. In the transmission process, the existing tooth root part and the Rapier belt hole wall contact tooth meshing transmission, but also has the Rapier belt and the transmission sword wheel inner surface contact friction transmission; The Rapier band's meshing angle to the sword wheel is usually 120~180, and in the case of equal pitch, there is no relative sliding between the rapier belt and the rapier band, the speed of the joints of the two is equal, and the reciprocating linear motion of the Rapier Belt is formed when the swinging rotation of the sword is rotated. Because the flexible composite belt has a certain rigidity, the rapier belt bending needs to withstand a certain bending stress, so the design of the curved plate to make the sword rod belt close to the surface movement of the sword wheel, but the use of the arc plate to make the latter part of the Rapier belt and its friction greatly increased and thinned.
Precautionary measures
The close degree of the Rapier weft movement and the warp opening movement in time can directly affect the wear of the rapier head. The opening time of the warp is too early, the contact between the Rapier head and the warp is less, and when the sword is returned, the contact with the warp will be more therefore, the sword head and the warp friction squeeze more; Similarly, the warp opening time lag, the return sword and the warp contact will be relatively few, but the weft-insertion sword head and the warp but contact more, therefore at this time the sword head and the warp friction squeeze also will be more.
When choosing the sizing material used in warp sizing, it is advisable to select chemical slurry and reduce the wear of the slurry to the sword head, which can prolong the service life of the sword head greatly. At the same time, it is very important to further study the coating technology of the sword head and enhance the wear resistance of the surface layer of the sword head.
In the process structure of loom, the rear girder height is small and the wear of the head is small. However, it is worth noting that the appropriate elevation of the rear spar to improve the quality of the cloth, cloth texture clarity, grain peak depth than the rear spar in 1000 mm is much better, so should determine the reasonable rear-spar height. When weaving warp-knitted fabrics, the rear girder height is generally about 1040 mm, so that the weaving can be made smoothly.
The quality of the coat of the head is very important for the use of the sword head. At high speed in and out of the warp composition of the shuttle, the warp to the blade surface produced alternating stress, so that the coating fatigue wear and spalling. And spalling of the debris is a very large hardness of the abrasive, in the role of the warp to form abrasive wear, over time, the substrate and the formation of a high degree of difference between the edge, resulting in warp cut and downtime.
From the rapier belt, the transmission of the sword wheel between the wear and tear to see, the technical staff in many times to change the Rapier loom Rapier belt movement trajectory measures to improve the Rapier belt and the transmission of the wheel between the meshing wear. The change of curvature and the degree of deflection directly affect the fatigue damage degree of the Rapier belt, the more the change point, the more serious the damage. The length of meshing between Rapier and rapier is increased, and the average force of the Rapier Belt and the wheel of the rapier is reduced, which is helpful to improve the service life of the Rapier belt and the transmitting sword wheel.