In the process of water-jet weaving in the polyester fabric industry, it is easy to produce silk-wound broken ends, falling pulp, abnormal weaving of weaving, cracking shaft, etc. It is believed that many enterprises have encountered similar problems. Below we will discuss the causes and propose corresponding solutions.
1, wool winding broken ends
In the weaving process, nylon, polyester and other synthetic filaments are easy to form a piece of wool near the heald frame and the steel shovel. Often, only a few of the tens of single fibers in a multifilament are unbroken, while other fibers are knives. It shears like a fracture. In severe cases, several multifilaments are "cut" together to form a piece of wool, and a twisted end is produced.
The main reason for this phenomenon is that the synthetic fiber has a high tensile strength and a low shear strength. When the filaments produced on one thread are twisted on the other thread, the filaments are not easily broken due to the large tensile strength during the separation of the two filaments, but the kinked fibers are The shearing strength is low and is “cut”, especially the non-twisted or low-twisted silk, the inter-fiber cohesion is poor, and the sheared fiber twists other fibers, thus “cutting” more single fibers, if not treated in time, Will accumulate into a piece of wool.
In order to prevent the yarn from being broken and broken, it is necessary to avoid the preparation process and the generation of the yarn during weaving. That is to do the following:
(1) Strictly control the processing tension of the wire in the preparation process. Under the premise of good forming, the processing tension of the wire is slightly smaller. If the tension is too large, the wire will be retracted due to the loss of tension after processing, and the bobbin The wall prevents it from retracting, resulting in a single fiber "cracking" phenomenon that is difficult to find visually. In addition to processing according to the controlled tension of the thread, the simplest method is to gently press the body with the thumb and the middle finger, and the thread is slightly sunken. It is advisable to prevent hard bobbins.
(2) The yarn guide should be smooth and wear-resistant and use high-performance ceramic materials that are not easy to generate static electricity, so as to avoid the fibers being broken during processing. In particular, it is necessary to prevent the use of a magnetic material because it is smooth but soft, cannot withstand the friction of synthetic fibers, will fluff, and wear synthetic fibers.
(3) The film is well formed and infiltrated on the premise of non-sticking. The well-formed silk can withstand the friction of the heald and the caries, while the well-filed wire has good bundling and is broken in a few wires. In this case, it can stick a plurality of fiber threads to avoid the generation of wool.
(4) The density of the healds at the heald frame should not be too large. According to the actual production experience, if the density of the healds is greater than 8/cm during weaving, it is likely that there will be friction between the wires and the healds, wires and threads due to repeated openings. In order to increase the number of heald frames, the simplest method is to use double steel bars, that is, to install two steel bars on one heald frame, and to separate the warp wires into the steel bars, which can reduce the total number of steel bars. The density of the silk prevents the generation of wool. And the heald frame should be changed regularly to prevent the warp from being “splintered” due to the roughness of the heald.
(5) The weaving workshop should maintain a certain temperature and humidity to prevent the increase of the static electricity due to the static electricity generated by the drying of the workshop. The relative humidity should be high, and can be controlled to 70% to 80%.
2, falling pulp
When the water jet loom is woven, white mushy or granular cohesive condensate, that is, falling slurry, often appears in the healds and steel shovel. These slags cause the warp threads to rise and fall up and down during the opening, thereby causing the shed Unclear, broken warp, broken weft, etc., in severe cases, weaving will also occur, affecting product quality and weaving efficiency.
Measures to prevent falling pulp:
(1) The quality of the slurry should meet the standards. All the test indicators must be qualified; the slurry can not be deteriorated; the general slurry dosage is 7% when the slurry is adjusted, and the water is added to 100%, and the viscosity of the slurry should be adjusted to meet the requirements. There should be no impurities in the slurry and additives.
(2) The slurry should be softened first, and the water hardness should be kept below 30 mg /kg; the boiling bucket and the mixing bucket should be washed; the pulping step is basically as follows: put 75 in the boiling bucket % water, start the stirrer at 80-120r/min, heat the water to 50-60 °C, put the slurry into the mixture, stir for 15-20min, add the auxiliary, stir for 15min, add water to 100%. use.
(3) The sizing process should be specially controlled to strictly control the viscosity and concentration of the slurry. During the sizing process, the viscosity of the slurry will rise due to the evaporation of water. Water should be added to prevent the rise, or the circulating slurry should be used to prevent the viscosity from rising rapidly. If the slurry feeding time is too long, the low-speed stirring should be carried out to prevent the slurry from being precipitated in the lower layer, resulting in the slurry viscosity of the used layer being too low. The slurry viscosity suitable for the process is the main measure to prevent the falling slurry.
The main reference processes are as follows: The pH of the slurry is 7 to 8, the solid content is 24% to 25%, the sizing rate is 7% to 8%, and the 77.7dtex/24f nylon yarn is sizing at a wire speed of 100 to 120 m/min, 166d tex. /36f Polyester processing wire sizing speed is preferably 80 ~ 90 m / min. The principle of the elongation control is that it is slightly larger in the case of breaking the head without affecting the performance of the thread. The slurry film thus formed can prevent the warp from being slightly elongated and stretched during weaving, 77. 7d tex /24f The nylon yarn is controlled from -0.9% to 1.2%, and the 166d tex /36f polyester processed yarn is preferably from 0.6% to 1.2%.
(4) When weaving, properly reduce the tension on the warp to prevent the film from being broken; the density of the warp yarns should not be too large, and the density of the healds on each piece should not exceed 8 pieces/cm. If it is too dense, it should be taken. For comprehensive measures, such as the selection of double steel bars; the relative humidity of the workshop is 70% to 80%, and the temperature is 24 to 28 °C.
3, the weaving axis abnormal jitter
After several years of use of the water jet loom, some of the loom weaving shafts will produce abnormal shaking during the operation. The domestic weaving machine is more serious, which will cause the warp to fluff and break, and the silk surface appears irregular. Crossbars reduce production efficiency and product quality. The main causes and prevention methods for the abnormal vibration of the weaving machine shaft are as follows:
(1) Improper determination of the tension of the warp machine, especially if the tension of the machine is too large, it is easy to cause abnormal shaking of the weaving shaft. Therefore, before production, according to the type of warp, the total number of warp threads and the thickness of the thread, the required total warp tension is correctly calculated to determine the mass of the weight, and the tension of the continuously variable transmission and the tension of the relaxation spring are adjusted. The weight arm is horizontal.
(2) Improper tension of the feeding belt. When using the tension measuring device to measure the tension of the V-belt, adjust the position of the V-belt to meet the theoretical requirements.
(3) The wear of the large shaft bearing of the weaving shaft causes the abnormal vibration of the weaving shaft due to improper force. The large shaft bearing and bearing sleeve should be inspected carefully to see if it is worn. If there is wear, it should be replaced in time; and the butter should be added when changing.
(4) The warp beam bracket and the warp beam cover should be repaired or replaced in time, and adjusted to meet the installation requirements.
(5) If the gear combination is improperly meshed, the transmission will be sluggish and the jitter will occur; the appropriate number of gear teeth should be calculated according to the weft density of the fabric, and the correct modulus fit should be selected.
(6) The gearbox lacks oil, damage, and rust drive is not correct and produces jitter. It should be corrected in time to ensure that there is no shortage of oil, no damage, no rust.
(7) When the shaft end of the weaving shaft is loose and the outer shovel can be repaired in time, it should be repaired immediately. If it cannot be repaired in time, it should be repaired in time.
(8) The weaving shaft bracket cover pin bolts should not be fully tightened and should be tightened in time.