The development and development of slub yarn has greatly enriched the varieties of denim. There are many specifications and varieties of slub yarn products on the market. According to the requirements of different specifications and varieties, in addition to changes in process technology, the equipment on the spinning yarn also needs to be partially modified to adapt to the production of certain special varieties.
Take the Shanghai ZP series intelligent slub yarn device as an example. This device is installed with a 20-tooth sprocket on the 104-tooth butterfly gear shaft of the FA506 spinning machine. Driven by servo motor. When spinning base yarn, the spinning machine is driven at a normal and constant speed. When spinning slub yarn, the servo motor accelerates according to the programmed program. The 20-tooth sprocket overdrives the middle and rear rollers to accelerate, which reduces the speed ratio of the front and rear rollers, instantly speeding up the feeding of the rear slivers, thereby obtaining slub yarn that meets quality requirements. However, when an irregular slub yarn is spun with a slub thickness greater than 2.5 times greater than the base yarn and a slub length greater than 100 mm, a large area of roving breakage will occur. Because the roving is unwinding and feeding at a constant speed and slowly, when the back roller momentarily exceeds the fast feeding with a longer segment, the roving strip is damped by the hanging spindle, the weight of the roving itself and the resistance of the upper and lower yarn blocking rods, and the roving strip suddenly increases the traction force, resulting in Unintentional drafting of roving strips before feeding. This results in many long segments with irregular details. In severe cases, about 1/3 of the roving strips are broken in the middle, resulting in many broken ends and empty spindles, making normal production impossible.
Solution: Remove the original fixed lower yarn blocking rod, install a 120 mm long movable connecting rod on the original fixed support rod, and install the lower yarn blocking rod at the lower end of the movable connecting rod. rod (see Figure 1).
When installing the lower yarn blocking rod, ensure that the yarn sliver is tilted inward at an angle of 110° to form an up and down yarn drawing curve, and the lower yarn blocking rod can freely swing back and forth. The lower yarn blocking rod is made of stainless steel rod with a diameter of 15 mm, which makes the yarn tension more suitable. When the feeder is quickly overtaken in an instant, the stainless steel lower yarn blocking rod is affected by the traction force of the roving bar. The position of the stainless steel lower yarn blocking rod naturally swings forward, and the yarn take-up angle becomes larger, overcoming the sudden traction force when the feeder is instantly overtaken; At the end of feeding, the yarn tension returns to normal, and the stainless steel lower yarn blocking rod slowly returns to its original position by its own gravity. In this way, the roving still maintains uniform unwinding speed. After a period of use, the original problem caused by the roving overtaking the feeding has been completely solved. The problem of large-area broken roving and long segment details and uneven evenness. It effectively improves production efficiency and product quality, and the effect is very good. </p
