How to make the high pressure sizing process work better?

At present, the shuttleless loom with the characteristics of “large opening, small opening, strong beating, high opening frequency” has been introduced into China in large quantities, which makes the requirements of the weaving machine more and more high in the weaving process, and requires the warp and weft yarns to have high strength. The utility model has the advantages of low strength unevenness, smooth yarn body, less hairiness, abrasion resistance and tensile resistance, so as to reduce the warp and weft break of the weaving machine and ensure efficient operation of the loom. How to improve the intrinsic quality of sizing and thus improve the efficiency of the weaving machine is an important task facing the textile enterprises.

High-pressure sizing is beneficial to improve the quality of the sizing, and is beneficial to reduce the sizing rate and increase the sizing speed. In the high-pressure sizing process, the slurry should be selected according to the yarn type, and the process parameters and the sizing operation should be reasonably set, so that the sizing moisture regain rate is within the scope of the process requirements, and the high-pressure sizing process is continuously studied, thereby effectively improving the efficiency of the loom.

So how do you make the high pressure sizing process work better?

The pressure of high pressure sizing should be set according to the yarn type.

The main points of the high pressure sizing process are high speed, high pressure and low viscosity. Usually, the pressure increase rate is ≤100%, that is, the sizing rate/solid content ≤1, which is the starting point of high pressure sizing. “Equivalent pressure pulp” means that according to the rated pressure slurry and the maximum speed of the sizing machine itself, regardless of any speed within the rated range of the sizing machine, it can reach the rated speed when the maximum speed is 100m/min. Pressure grouting effect of 40kN. Under normal circumstances, the normal speed is generally 70%~80% of the rated speed, that is, the yarn type is at the normal speed, the grouting force is in the range of 20kN~40kN, and the sizing coverage should increase the grouting force accordingly.

Many yarns, especially those with large groove coverage, such as coarse yarns and high density, are difficult to achieve high speed, and require large pressure pulp to achieve good sizing and hairiness stickers. The effect of the service; while the yarn number is finer and the density is lower, the sizing speed can be improved, but the pressure force requirement is not too high, and the pressure force can be moderately reduced. In the production, the sizing pressure can not be uniformly set, and the pressing force should be adjusted according to the yarn type and the sizing coverage. The high-pressure sizing process has wide variety adaptability, the sizing coverage is large, the grouting force should be correspondingly increased, the sizing coverage is low, and the grouting force can be appropriately reduced.

High-pressure sizing process should be reasonably configured in high-pressure sizing 2

The sizing process should be based on the warp and weft yarn density and fiber composition analysis of the yarn variety to determine the sizing process and the selection of the slurry. The sizing moisture regain rate must be determined according to the fiber's specified moisture regain and blending ratio. In commonly used varieties such as pure cotton, polyester cotton, polyester , viscose , cellulose fiber (Lysel, Modal), hydrophobic fibers are not easy to sizing, light water-based fibers are easy to sizing, and the corresponding slurry selection should also be different. For special varieties such as fine yarns, high-density high-density yarns, and high sizing coverage, low-viscosity slurries should be considered to increase the fluidity of the slurry tank. The lyocell and modal yarns are high in strength and long in hairiness. The sizing should be based on hairiness, preferably with or without PVA. Need to use PVA varieties must control the degree of polymerization of PVA, the degree of polymerization is too large, the serosa is hard, the twisting is difficult, the hairiness is not good, and the head is easy to break. In addition, the degree of polymerization and the degree of alcoholysis must be controlled. The higher the degree of PVA polymerization of fully alcoholysis, the lower the rate of impregnation. The PVA penetration rate of partial alcoholysis is higher than that of fully alcohololysis. Therefore, the degree of polymerization of PVA is reasonably selected. The degree of alcoholysis is quite important for the quality of the sizing.

Reasonable control of moisture regain in high pressure sizing 3

In production, whether the sizing machine is at normal or slow speed, the sizing moisture regain can not change much and should be relatively stable. Maintaining the sizing regain rate is essential for the film to remain relatively intact and to reduce secondary hairiness, and it can play a key role in ensuring the clear opening of the loom and reducing the lint and fabric neps. Under the condition that the process setting is reasonable, the normal speed can guarantee smooth production. Slow trains often have a phenomenon of too low moisture regain, resulting in increased rupture of the sizing dry area, increased hairiness, easy yarn breakage, hair entanglement, and even broken ends. Smear slowing down will result in the corresponding pulp shaft being good and bad when it is being weaved, and sometimes there is a condition of neps, which causes the efficiency of the loom to fluctuate greatly. When manipulating the local train, such as the pull wire, the full shaft, and the cutting shaft, the warp beam is wrapped around the shaft. Before closing the car, the drying cylinder valve is closed in advance to control the regain rate of the local train to 6% or more.

The low regain rate of the sizing has a great influence on the hairiness, especially the lyocell and modal varieties. When the regaining rate is small, the sizing of the sizing increases after the yarn exits the drying room. This phenomenon can only occur if the moisture regain rate meets the process requirements. In production, some companies have unreasonable design of the sizing machine, so that the sizing machine can not track correctly. After the process of setting the pressure, speed and moisture regain rate parameters, after the driving operation, the process requirements are not met. This is because the setting temperature of the main and pre-drying cylinders is too high, which is beyond the tracking range and is not suitable for the variety. Claim. Therefore, the sizing process can be properly set to fully utilize the automatic tracking function of the sizing machine. The choice of sizing moisture regain rate should be based on the reasonable moisture regain rate of the fiber and the ratio of the fiber. At the same time, the speed of the sizing speed is controlled, and if necessary, the temperature setting of the main baking and pre-baking of the drying room is adjusted to achieve the process moisture regain. Ensure the stability of the sizing process moisture regain.