1. Start with each process of pre-spinning and semi-finished products
1. For clearing the falling objects, by adjusting the distance between the a036 and a076 dust sticks, the falling object rate is changed from 2.57 percent to 4.43 percent ; for carding the falling objects, the falling object rate can be changed from 5.2 percent by adjusting the distance between the rear belly falling objects. into about 6.5 percent . After adjustment, the hemp rods and hemp skins on the yarn surface are reduced, and the chance of mixing during weaving is also reduced, which can reduce the "triple jump" defect by 20 percent to 30 percent .
2. Rapier looms have higher requirements on the quality of the original yarn, the less the unevenness of the long segment, the better. Generally, it is required to be 3 percent to 4 percent , the evenness cv value is 20 percent to 25 percent , and the single yarn strength cv value In 18 percent to 20 percent .
3. Improve the quality of the joint, the length of the end is generally 1.5mm 4mm is the best, and the joint with a large twist should be especially prevented from small braids.
4. Warping requirements ensure "three spirits", that is, flexible rotation of tension ring, flexible braking, flexible automatic stop when broken ends, and at the same time slightly heavier side yarn, so that the tension of the whole warp yarn is uniform.
5. Improve the quality of sizing, improve the clarity of warp openings, reasonably select the sizing and formulate the sizing rate according to the variety. Generally, the sizing rate of hemp cotton is 8 percent to 9 percent , which can satisfy the formation of a smooth and wear-resistant sizing film on the surface of the warp. To correctly control the moisture regain, if the relative humidity of the weaving workshop is above 80 percent , the moisture regain of the sizing can be controlled at about 7 percent to 8 percent ; the elongation of the sizing should be reasonably controlled, and the sizing fabric should be controlled below 1 percent ; the enhancement rate is in the range of 10 percent to 15 percent , which can meet the requirements of rapier loom fabrics.
2. The timing of opening and feeding should be properly coordinated. Generally, there are more opportunities for yarn skipping defects on the side of the weft feeder. Therefore, different configurations can be used to adjust the weaving parameters on both sides. The feeding time of the weft sword is appropriately advanced, so that the weft sword can enter a clearer weaving mouth. Generally speaking, the opening time of hemp and cotton varieties should be 290 degree -300 degree , and the sword feeding time is 70 degree -75 degree . When feeding the sword, the position of the weft feeding rapier is 4 to 6 guide pieces away from the weaving mouth, and the position of the weft receiving rapier is 2 to 20 degrees away from the weaving mouth. 4 guide rails, and also ensure that the sword enters slowly and the sword exits quickly so that the sword has enough time to pass through the clear kendo and reduce the chance of yarn jumping.
3. Adjustment of the warp position line Adjust the height of the position line, generally only adjust the height of the drop frame and the rear beam. When the drop frame and the back beam are raised, the tension difference between the upper and lower warp yarns increases. When the weaving fell is fully opened, the lower warp yarns are tight and the upper warp yarns are loose so that the warp yarns are evenly arranged and a fuller cloth surface can be obtained. If the lift is too high, the upper warp yarns are too loose, and the warp yarns stick to each other, making the opening unclear and prone to star jumps. Generally, the height of the back beam of hemp and cotton varieties is 70mm to 80mm, the height of the drop frame is 30mm to 40mm, and the two ends should be kept horizontal.
Fourth, the correct hanging heald specifications generally control the lower warp yarns to be slightly lower than higher. During the upper shaft and maintenance work, the lifting heald should be adjusted to ensure the "three alignments", that is, the alignment of the heald frame, the alignment of the tread bar, and the alignment of the tread plate and the rotor. "Siping" means that the heald frame (heddle bar) is flat, the lifting bolt is flat, the hanging heald plate is flat, and the stepping heald rod is flat. If it is unqualified, check whether the heald clip falls off, whether the top wire of the tread plate is loose, whether the bearing pad of the hanging heald is worn, whether the hanging heald belt is deformed, etc. Generally, the front and rear positions of the hoisting shaft are about 110mm to 120mm, the movement does not exceed 0.8mm, and the height of the hoisting shaft is 400mm to 410mm. The above measures have been tested on the GA747 loom for weaving 8s8s4238 hemp-cotton plain weave. The efficiency of the loom was increased from 50 percent to 65 percent , and the number of "three-jump" defects was reduced from 500 to about 200 in 90m cloth.