Causes of shutdown marks
There are many reasons for the occurrence of stop marks: the sudden change in the amount of yarn feed causes uneven yarn tension, which changes the shape size of the coil to form a stop mark; the relative swing between the feed drive gear the main shaft of the loom will position the groove of the drive gear 1. The positioning pin of the transmission shaft is worn out. In serious cases, the gear shaft center will also be worn become larger, which will affect the yarn tension cause stop marks; the relative slip between the yarn feed adjustment disk the storage belt of the accumulator due to the glue in the yarn feed adjustment disk The wear of the pellets the storage belt of the yarn storage, the insufficient pressure between the transmission belt the rubber particles, the sudden change in the speed of the loom during shutdown start-up causes the friction coefficient between the rubber particles the conveyor belt to become smaller, forming a relative slip, resulting in a unit The change in the number of turns of the yarn feed, which in turn affects the yarn tension forms a stop mark.
The wear of the storage teeth of the yarn accumulator the filling of the flock, the wear of the conveyor belt of the yarn accumulator, make the yarn accumulator the conveyor belt slide more intensified during the shutdown start-up of the loom, resulting in a decrease increase in the amount of yarn per unit of yarn , Forming a shutdown mark. In this case, the stop mark is wider, which is also caused by the change in the length of the coil. The length of the coil will generally change by 2% to 8%. Too loose abrasion of other related transmission belts in the yarn feeding system will also cause uneven tension during shutdown startup form shutdown marks.
Ways to improve downtime marks
In general, the main ways to improve the stop mark are to prolong the deceleration time of the loom, increase the blank braze force, reduce the virtual position of the riser of the triangle seat chassis, the model.
The longer the loom is in the process of deceleration, the smaller the oscillating change rate between gears the relative sliding change rate of the transmission belt, so that the tension change of the yarn is too rapid, thereby reducing the degree of stop marks. The longer the braking time, the longer the loom continues to run after the yarn break. Due to the limitation of the yarn storage capacity of the yarn storage, the general braking time is set to 1.5 seconds to 1.8 seconds, so as to ensure that the yarn will cause rotten cloth after the yarn break.
Improving the stop mark can also be achieved by reducing the virtual position of the riser of the tripod chassis. That is to reduce the meshing gap between the gears the relative swing gears between the gears the shaft, reduce the virtual position between the needle the triangle (the virtual position of the leaf bed). In order to ensure the normal operation of the loom, the virtual position of the leaf bed can generally be controlled at about 0.1 mm.
At present, most models of the needle cylinder triangle base use a central lifting device, the ascending point of each rising point has a large virtual position, so that when the knitting needle quickly rotates, the triangle seat is thrown up the tension changes. Properly reducing the virtual position of the supporting rod can ensure that the central lift can be used normally will cause the tripod to be thrown too seriously. When the loom rotates normally, the throwing amount on the triangle base is generally controlled within 0.03 mm.