No 9, 10th Streest, HEDA, Hangzhou, Zhejiang, China
Analysis of Reasons for Air-jet Loom Heddle Frame Wearout
Due to the high weaving speed, and difficulty of weaving species, the heddle frames on air-jet looms are more likely to wear. We have made an analysis based on the wearing status, and gave relevant suggestions and solutions, to lower the wearout of parts and improve production efficiency.
1. Longitudinal Grinding Defect The upper or lower cross beam of heddle frame has one or several longitudinal grinding defects, with different depth, the severe ones even stuck through the heddle frame. The defect is caused by the abrasion between front heddle wire and backside heddle frame, main reasons listed below;
1) Heddle wires are not fully repaired. The unqualified heddle wires have not been spotted and replaced.
2) Staff mistake during the drafting process, heald loop is not installed in place.
3) Due to various reasons, the heddle wires are deformed and crossed. Heddle frames have severe abrasion in this circumstance. The reasons for heddle wires deformation can be staff faulty operation during heddle wire drawing and beam doffing; sundries on the warp yarn like stuck the eyelet, avoiding the yarn enter successfully, and heddle wires are deformed due to longtime stretch.
2. Lateral Wearout Multiple spots of lateral wearing appear on the lower edge of the upper cross beam and the top edge of the lower cross beam, the wearing may happen on more or less of the heddle frames, but not critical. Main reasons are listed below;
1) The thickness of yarn and big weft density cause big vibration on the fabric surface, leading the performance of heddle frames not stable.
2) Too much heddle frame height causes vibration on the surface.
3) Too much flying between heddle wires, cause deformation of heddle wire in motion, hence lead to wearing.
3. Measures to be Taken 1) Self-check by the weaving workshop, and analysis of the reasons for abrasion. During the preparation process, each heddle frame should be checked and recorded if any abrasion appears. Maintenance should be done properly and recorded. It is requested that no flying on the heddle frames, all deformed heddle wires are corrected and restored, and some replaced if severely damaged. Waxing will be conducted, and silver powder applied at the place of abrasion.
2) The staff for heddle drawing should check each heddle while drawing, improve his technique, and avoid mistakes. Specialized tools are required for the inspection of all corrected heddle wires. Heddle frames should be installed in place, and keep extra 2 heddle wires for back-up.
3) Strict execution of measurement standards, and optimize the preparation work. The distance of each heddle frame should be kept as 2mm, ensure the parallel of heddle frames, any deflection will easily cause heddle frame wearing. It is not advisable to completely follow the processing parameter from the computer, especially the heddle frame height. For high-density fabric with great thickness, heddle frame height should be 2 to 3mm lower or even more. The below-listed table is the comparison of suggested value and practical value in the application of GroB heddle frame on ZAX-N-210 1661 model;
For high-density fabric with great thickness, and a high degree of difficulty, the shed opening time can be brought forward 10°, and shed opening increased by 4mm; it can reduce loom vibration and heddle frame wearing to the utmost extent.
4) The loom tension should not be too big, as it will also cause heddle wire deformation.
5) While weaving low-density fabric with thick yarn and relatively less total warp ends, duplex heddle wire can be replaced by simplex to reduce the chance of wearing, but different of heddles should be classified and avoid mixing.
6) The flying between heddle wires should be blown away thoroughly, manual cleaning needed when necessary.
7) The shifts of maintenance staff should first conduct overall checking of the loom to see whether any heddle frames wearing or crossing of heddle wires. The loom should be stopped immediately once anything abnormal is spotted.