Cloth weaving defects are an important factor affecting the quality of textiles. As the use time of the loom increases, the equipment continues to age, and the damage to the loom accessories, healds, reeds and other equipment also accumulates. In addition, the continuous maintenance and repair of the equipment cannot completely repair the damage, which brings about quality problems. New control problems, scratches and defects on gray cloth are one of them.
Hairy attached scratch defects are caused by the obstruction of the passage route after the yarn is woven into cloth. face front or backOn the surface, the hairiness leaking out of the cloth surface is completely attached to the angle of the cloth surface. At the same time, the internal fibers of several yarns are also damaged due to external forces. After finishing, the cloth surface shows streaks, which are more obvious after dyeing. This kind of scene is also called a scratch defect.
Abrasive defects occur during the weaving process, between the cloth surface or a single yarn and the loom The damaged parts rub against each other, causing yarn damage. This defect is briefly described as abrasion marks below. From the outside, the gloss of the cloth surface under the light is different. One or more continuous strips are shiny. If you look closely, the cloth surface is slightly sunken, like a wheel running over it. Severe yarn fiber bundles have been damaged and the force damage is serious. . After finishing, desizing, scouring, bleaching and mercerizing, the cloth surface will show obvious streaks and defects. Such defects are continuous, making it difficult to avoid cutting in garments. Therefore, preventing and controlling the occurrence of scratch defects is the top priority of quality control in the weaving process.
1. Pre-control and inspection methods for various types of wear marks during gray fabric weaving
During the use of the equipment, various parts will cause more or less damage. The longer the machine is used, the worse the rotation flexibility and stability of the equipment will be, and more quality will appear during the weaving process. Hidden dangers. In view of the current situation that wear marks are easily caused in the production of woven white fabrics, and based on the characteristics of each loom in the workshop, the experience of preventing and controlling wear marks in production is introduced.
1.1 Prevention and control methods of warp scratch defects on cloth surface
1.1.1 Check the reed quality before the fabric is put on the machine
Do not use the steel reed if the reed teeth are bruised, especially if the front of the reed teeth is damaged and deformed, protruding to both sides. During the process of swinging back and forth on the machine to beat weft, the protrusions on both sides of the reed teeth scrape against the warp. Rubbing will cause internal damage to the yarn. Such warp scratch defects are not easy to be found on the cloth surface. The special-shaped reeds of Japan’s TAKAYAMA company used in gas-type looms are made of 420JR wear-resistant stainless steel and are highly rigid. The reed teeth rarely have such abnormalities. The blue sword reed teeth used on rapier looms are made of iron and are prone to such abnormalities. The front bump of the reed teeth is a key inspection point for meridional scratch defects.
1.1.2 Quality inspection of weaving beam equipment
Check that the drop pieces, healds, etc. are not bent, deformed, or worn. stopThe warp pieces and heddles constantly rub against the warp yarns during use, causing a deep groove to be worn along the lower edge of the middle heddle eyelet. The friction between the yarn and the heddle eyelet groove can easily damage the internal structure of the yarn. Especially when the installation direction of the healds is inconsistent with the direction of yarn passing, the yarn and the heald eye groove will rub in reverse direction, aggravating the yarn wear. The wear of such a single yarn is not easy to find on the cloth, but after processing to deboiling and mercerization, the defects on the cloth are particularly obvious.
1.2 Inspection of the contact points between the warp yarn and each position of the loom before weaving the fabric
1.2.1 Check the cloth support rod at the cloth fell
After weaving the previous variety, turn and curl the gray fabric so that the gray fabric completely leaves the fabric support rod. Gently touch the front end and top of the fabric support rod with your hands to check whether it is flat and whether there are burrs. If there are any unevenness, Also use coarse sandpaper to polish first, then fine sandpaper to polish, and then use zero-angle gray cloth to grind out a smooth surface before use. When changing the width, the gap between the fabric support rod and the side support seat must be adjusted to 0.5. cm, to prevent the gap from being large, causing part of the cloth surface to be unstressed, and causing excessive stress on the cloth surface next to it, causing wear marks on the cloth surface. Also, check whether the cloth surface pressing rod is smooth, round, and free of burrs, etc. to ensure that the cloth surface is smooth. No hard objects to slide.
1.2.2 Check the temple halo and temple connection
After the weaving type is hung up, before installing the temples, check the loom temple heads and temple rings Check whether the rubber ring and side support seat are worn or have protruding burrs. They must be smoothed with sandpaper and polished with a zero-point gray cloth before use. This kind of mechanical damage to the loom will cause damage to one or more yarns on the cloth. Generally, it can be found on the cloth and corrected in time.
1.2.3 Inspection of burrs on the cloth guide rod behind the cloth roller
After the gray fabric is woven to a length that can bypass the curling lower fabric guide rod, remove the gray fabric from behind the fabric guide rod Bypass, check the quality of the loom guide rod before fixing the leading end of the cloth to the cloth rod. The cloth guide rod removed from the Tsudakoma loom is a smooth stainless steel tube, which is easy to inspect. The cloth guide rod of the Picanol loom is a threaded rod. The threads expand outward to make it easier to spread the cloth. There is no thread in the middle 15 cm. The burrs on this threaded cloth guide rod are difficult to see and must be inspected carefully.
1.2.4 Installation of the warp drop frame yarn dividing plate
After the yarn surface on the back beam of the loom is flat, when installing the yarn dividing plate, fixing the warp stop frame, and adjusting the yarn dividing plate, it must be ensured that the yarn dividing plate divides the yarn evenly, and there is no scratch between the yarn and the yarn dividing plate. There should be no burrs on the outer edge of the yarn board.
Special attention should be paid to repairing if wear marks are found during the weaving process. Do not repair the side braces, halo, Pasting tape paper on the support table or support rod is a method of controlling wear marks. It is like drinking poison to quench thirst. Once the tape paper wears off during the weaving process, wear marks will inevitably occur.
1.3 Inspection method for warp scratch defects on cloth surface after weaving
The new machine operator will focus on checking the wear marks at the temples after taking out the cloth sample. Only the operator can find them, and the mechanic can repair them step by step. For the wear marks where the fiber structure of a single yarn has been damaged, It is not easy to detect from the fabric surface. You can check the equipment in advance to prevent it. After weaving the sample fabric, do the inspection after desizing and mercerization. The following focuses on the prevention and inspection methods of attached wear marks.
Hairiness-attached wear marks are caused by the fact that after the yarn is woven into cloth, due to the obstruction of the passage route, the hairiness leaking out of the cloth surface is completely adhered to an angle flush with the cloth surface; at the same time, several yarns are internally Fibers are also damaged due to external forces, and streaks appear on the cloth after finishing, which are more obvious after dyeing. This phenomenon is also called scratches. Such wear marks can be discovered by the difference in light on the cloth surface. Due to insufficient light intensity in the workshop, the illuminated fabric is not obvious. However, the fabric will be very bright when illuminated with a hand lamp. The method of illuminating the fabric is introduced as follows.
The light direction of the hand lamp is at an angle of 10° to the cloth surface, and the human eye looks at the cloth surface in the direction of the light, as shown in Figure 1.
Figure 1 The angle of the hand lamp illuminating the cloth
Outside the focus area of the hand lamp, the wear marks are bright in the light coverage area, as shown in Figure 2.
Figure 2 Bright refraction points of wear marks
For front wear marks, no mop is needed. The hand lamp is placed on the threaded rod behind the cloth roller, perpendicular to the cloth roller and close to the cloth. Light the surface at an angle of 5° to the cloth surface, and examine the cloth surface with your eyes downward from the curled felt roller.
For reverse wear marks, the hand light is perpendicular to the cloth roller, and the hand light is illuminated upward from the outside of the cloth roller. Mark the tangent line on the cloth surface of the circular cloth roller, and check the wear marks with your eyes facing the direction of the light.
This method of lighting the fabric is only suitable for hairy adhesion wear marks, caused by wear on the left and right sides of the yarn The wear marks cannot be seen by shining a hand lamp on the cloth, so it has no effect.
1.4 Inspection of latitudinal wear marks
Weft wear marks generally appear on weft polyester filament and nylon varieties, due to the weft yarn from the yarn The gap between the tube and the swing nozzle is caused by wear during flight. When this kind of wear mark is inspected on the cloth surface, it is not like a rut along the meridional direction like the meridional wear mark, but a wider strip in the meridional direction. Some of the strips are also curved. When viewed against the light, Hairiness increased significantly, and uneven dyeing appeared after dyeing. This type of wear mark is also called abrasion defect. The following parts should be mainly checked during weaving.
(1) The part from the weft yarn to the weft feeder: This part is easier to check and can be viewed directly during driving. When you arrive, focus on checking whether the weft tensioner is smooth and whether there is any foreign matter blocking it. Generally, there will be no yarn wear in this part.
(2) The part from the weft feeder to the swing nozzle: This part is not easy to inspect because during the weft insertion process, the weft yarn between the weft feeder stop pin and the PFT weft insertion channel swings. Key inspections The parts are the weft storage drum, magnetic pin, PFT yarn presser and swing auxiliary spray nozzle.
(3) Weft storage drum part: The weft storage drum is used to wind and store the weft yarn for a single pick. This position is prone to problems, because every time the variety is changed or the length of the edge yarn is adjusted, it must be disassembled and adjusted. During the disassembly process, the operator did not operate according to the standard and did not completely loosen the fastening screws. He used a wrench to hit the weft storage drum, causing burrs on the weft storage drum and causing damage when the weft yarn came out. The weft yarn for a single pick is generally set to 4 turns, and such wear marks appear as 4 strips on the cloth surface.
(4) Magnetic pin position: The magnetic pin is used to control the opening and closing of the weft insertion. The magnetic pin opens and closes frequently and constantly rubs against the weft yarn, causing damage. When the magnetic pin is damaged,The weft yarn is damaged at the moment of weft insertion, and such wear marks will appear as a band on the cloth surface.
(5) PFT yarn presser position: PFT yarn presser is used to weave the weft on the right side of the weft yarn Before, let the weft yarn pre-decelerate and straighten, and then cut the weft yarn with the left scissors. Every time the PFT yarn presser picks the shuttle, it will rub against the yarn at high speed. It will be scratched after being used for a long time, which will also cause the wear and tear of the yarn. Such wear marks will generally appear as a band on the left side of the cloth. .
(6) Position of the swing auxiliary spray nozzle: The swing auxiliary spray nozzle is used to accelerate the weft yarn and control and stabilize the weft yarn flight path. The rear end of the swing auxiliary spray nozzle is a porcelain eye, which generally does not cause scratches. The front end is metal, which will cause wear and tear after being used for a long time. At the same time, the weft yarn is worn during the swing process. Such wear marks generally appear as a band on the right side of the cloth surface.
The above inspection methods for wear marks and the inspection methods for meridional wear marks The same, and then according to the shape and location of the wear marks, determine the faulty component and repair or replace it.
2 Conclusion
Whether yarn-dyed or piece-dyed, it is not a simple dogmatic management and control, it must be fully integrated with the loom The key to weaving high-grade fabrics is to adopt an effective and reasonable plan based on the actual conditions of the raw materials. When textile companies with export labels encounter development bottlenecks, it is inevitable that orders will drop and costs will be cut. They should take advantage of the “three realities” of on-site, reality, and current goods to adopt reasonable implementation methods to improve product quality and reduce costs. Quality cost can improve the competitiveness of enterprises and win the market for them.
