Common defects are the main factor affecting the weaving efficiency of rapier looms. Based on production practice experience, summarizing general prevention and control measures can help improve the weaving efficiency of rapier looms. Let's learn about common weaving defects and their prevention and control together!

Hundred Legs

The double weft legs of a rapier loom are divided into full width legs, quarter width legs, edge legs, and regular legs based on their appearance on the fabric surface.

Yuan Baijiao

If the length of the weft insertion exceeds the set length, the weft yarn will expose an additional end of the thread outside the fabric end on the weft insertion sword tip side. When the weft insertion sword tip enters the kettle mouth the next time, the end of the thread will be brought into the kettle mouth, forming a hundred legs at the fabric end on the weft insertion sword tip side. Preventive measures: Adjust the unwinding time of the weft unwinder so that each weft can maintain a long thread head of 5mm~10mm when unwinding outside the weft insertion side kettle.

When the tension of the weft yarn is too high, the weft yarn will rebound when it is released to the outside of the weft end on the weft insertion side, causing the weft yarn to shrink into the opening of the cauldron, further reducing the weft yarn at the side weft end and forming a hundred feet at the end. Preventive measures: Reasonably adjust the weft cleaning clearance of the weft storage device and the winding gap of the drum, as well as the tension of the yarn clamp.

In high elasticity fabrics, due to the high elasticity of the weft yarn, it is released and moves backwards to the left, creating an edge at the end of the right fabric. Preventive measures: Increase the number of waste edges and accelerate the opening time.

One quarter width and one hundred feet

The belt is too loose, and after the bottom plate of the rapier tip is worn, the rapier tip sinks. The size of the double rapier tip does not meet the technical requirements. Due to reasons such as the clamping of the weft insertion rapier tip on the weft yarn being too loose or too tight, the weft insertion handover fails. When the weft yarn is introduced into the middle of the shuttle, the rapier tip is brought back. Prevention and control measures: reduce the gap between the leather belt and the guide rail, strengthen the inspection and adjustment of the weft insertion technology, and ensure that the weft insertion head moves normally and the handover is smooth. Pay special attention to the stroke of the weft insertion head and the automatic stroke of the double heads.

Due to high paper roller, low weft tension, or other reasons, the weft yarn becomes loose and enters the clamp, but does not get stuck on the receiving needle at the back of the clamp, resulting in a failed weft insertion. Preventive measures: Check the height of the picking rod. When the picking rope is fully stretched, the front end of the picking head should be 1.5 mm away from the guide rail; Check the tension of the weft yarn to make it moderate.

Total width width

The tension of the weft yarn is too small, especially when using both forward and reverse twisted weft yarns, the weft yarns are tangled together, and the easily twisted double threads are introduced into the sword tip, forming a full width foot. Preventive measures: Adjust the tension of the weft insertion appropriately to prevent the weft yarn from winding.

Due to the fact that the weft yarns are not broken and continue to break, two weft yarns are simultaneously introduced and extended to the entire width. Preventive measures: While cutting off the weft yarn, strengthen regular maintenance work. It can be combined with the inspection of the upper shaft to immediately replace the severely worn neck of the side shaft and non sharp blades.

Rule based hundred feet

Email errors caused by malfunctioning parts, incorrect paper patterns or blockages in the opening mechanism; The knife is severely worn and engages too shallowly with the hook. Once it slips, it will exhibit regularity. The morphological feature of regular legs is that the intervals between the legs are basically consistent. Prevention and control measures: Strengthen the inspection of weft insertion and opening components, check the textured paper, and clean the faucet; Replace the upper and lower knives. Other Hundred Legs

When the height difference or one side's height is low, it can cause local poor opening, forming regional or semi wide legs; When the mail card of the comprehensive frame falls off, the mail is disconnected, or falls off, sometimes it may become a hundred feet locally; Each connecting rod has broken at a certain point, with excessive wear on the shaft and protrusion, resulting in loose engagement with the heald frame, uneven synthesis, poor opening, and the formation of half width or small fragments of a hundred feet. Prevention and control measures: Strengthen the maintenance of the opening mechanism, carefully adjust the hanging mail, and strengthen the inspection of the comprehensive frame and comprehensive management.

The gripping force of the rapier tip of the weft yarn is insufficient, and the tension of the weft yarn on the spring plate of the gripper is too high to hold the weft yarn. The rapier tip slips inside the shed and forms a hundred legs at the right end of the fabric. Preventive measures: Maintain the sword head to ensure the normal operation of the weft clamp and control the weft tension.

Triple jump

In weaving, the defects of warp yarns are often entangled with adjacent yarns, and some warp yarns have unclear openings; Poor sizing quality and heavy fuzziness, especially when the tension of the fabric surface is relaxed; The high moisture regain rate of the weaving shaft can easily cause flying flowers to accumulate between the stop pieces during the weaving process, and the broken warp closure car may malfunction. When the weaving machine continues to operate, the broken thread tail winds around the adjacent thread, and the opening is not obvious, all of which cause the "three jumps" problem. Preventive measures: Starting from each process of spinning and semi-finished products, improve the quality of raw silk and sizing, and carry out cleaning work in a timely manner; In order to accurately grasp the tidal rate, when the relative humidity of the weaving factory is above 80%, the tidal rate of the sizing can be controlled at around 7% to 8%; When blocking the car, immediately remove the thread.

The opening time and entry time are not coordinated, and when the weaving height is insufficient, the sword head enters and exits the kendo, causing edge flower flying and thread flying. Prevention and control measures: appropriately delay the insertion time of the weft insertion sword tip, appropriately advance the insertion time of the weft insertion sword tip, and place the weft insertion sword tip into a clearer weave.

Shorten latitude

In the weaving process, if there is a lot of warp yarn fuzz and uneven yarn tension, due to the significant difference in the bending state of the weft yarn at the weaving mouth after weaving, the fabric surface effect is not good, resulting in defects similar to weft shrinkage and weft shrinkage. Preventive measures: Increase or decrease the tension on the machine appropriately.

The magnitude and stability of weft tension greatly affect the rebound effect of weft yarn. Excessive or insufficient tension can affect the occurrence of weft shrinkage defects and the quality of the fabric surface. When the tension of the weft yarn is low, the elongation state of the pulled weft yarn becomes insufficient, which is prone to weft shrinkage. The weft yarn bending during weft winding increases, and the amount of weft yarn used increases; When the tension of the weft yarn is high, the rebound of the weft yarn after discharge is more obvious, and it will also form weft shrinkage defects. The manifestation and distribution area of weft shrinkage defects vary depending on the magnitude of tension; To stand out in the actual production process, maintain the size and stability of the weft tension. Preventive measures: Properly control the tension of the weft yarn.

Due to the excessive dynamic tension of the weft yarn, the weft insertion sword tip releases the weft yarn outside the edge of the fabric, causing the entire weft yarn to suddenly lose traction and quickly rebound and retreat, resulting in weft shrinkage. Preventive measures: Properly control the tension of the weft yarn. After the weft yarn is released from the weft insertion rapier, it can be fully stretched to avoid rebound and twisting. Sparse and dense road

When the loom stops and starts, due to the change in warp tension during the opening movement, there is a difference in the displacement before weaving, resulting in a dense path. Especially, if the tension of the lower warp is too high and the tension of the upper warp is too low, this disadvantage is more likely to occur. Preventive measures: Reasonably control the tension difference between the upper and lower layers, and reduce the displacement of the weaving mouth; Improve the level of parking operation.

The cause is the entanglement of the sword tip, which prevents the weft yarn from being smoothly clamped and picked up during driving. Preventive measures: Timely carry out sword head cleaning work.

When the loom is restarted after stopping, the weft insertion force is less than that during normal operation, and the insufficient weft insertion of several weft yarns after operation leads to the occurrence of a loose path. Preventive measures: comprehensively level the stopping position and reduce the stopping frequency.

The surface of the taker in roller is worn and slippery, and there are too many flying flowers attached. The effect is uneven when rolling cloth, forming a secret path. Preventive measures: Clean the surface of the burr roller well; Replace the sesame skin immediately.

The above introduction is about the common weaving defects and prevention of rapier looms. When weaving fabrics on rapier looms, there are four common defects: hundred legs, three jumps, weft shrinkage, and sparse and dense paths. However, the degree of other defects varies depending on the model and mechanism performance of each rapier loom. To reduce common weaving shortcomings, we mainly start from the following aspects. Strengthen machine maintenance work, especially the maintenance of the rapier weft insertion system, and lay a solid foundation for the machine; Pay attention to the quality inspection and improvement of raw silk, and meet the characteristics and requirements of weft insertion technology in rapier looms; Reasonably design and adjust the opening weft insertion technology; Improve the operational skills of rapier looms.