为什么有的经丝需要上浆？有的经丝可以免浆？在这里可以找到答案/Why do some warp yarns need sizing? Some warp yarns can be free of pulp? Find the answer here
Why do you want to sizing? What is the mechanism of sizing? What issues should I pay attention to?
The synthetic filaments are made up of a plurality of single fibers, such as 165dtex/48f, which means that 48 single fibers are combined into a 165dtex multifilament. During the production process, the filaments are subjected to the network under stress. In the weaving process, it is subject to repeated friction of the guide rolls, healds and steel shovel. The friction of the wire is more than 10,000 times, and the speed of the weaving machine is generally 500~700r. /min, high-rate friction monofilament is very easy to fluff, not only affects the efficiency of weaving, but also causes the weaving to be impossible, and the quality of the product is significantly reduced. For this reason, the sizing or sizing of the non-twisted or low-twisted filaments is required. The warp yarn can withstand the friction during processing and smoothly weave, and guarantee the quality of the product.
The mechanism of sizing is: after sizing, the slurry forms a slurry film around the silk body to resist the friction of various equipment; while the slurry penetrates into the single fiber, the individual fibers are stuck, and the multi-fiber bundle is improved. And strong, so as to ensure the smooth completion of the tasks of the subsequent process. Due to the large hairiness of the spun yarn, the sizing effect is required to be mainly coated, and the sizing of the synthetic filaments is mainly based on infiltration and supplemented by drape. Due to the low moisture regain of the synthetic filaments, such as polyester yarn with a standard moisture regain of 0.4% and nylon of 4%, they are hydrophobic fibers, that is, they are not compatible with water, so their sizing is not as easy as viscose. It must satisfy two conditions: the viscosity of the slurry is particularly good, and the slurry can adhere the single fibers to each other after infiltrating into the single fiber, ensuring satisfactory bundleability and forming a good serosa around the filament. To ensure its good wear resistance. In the case of the pulp, it is necessary to ensure a certain distance between the filaments, and the multifilaments after the sizing are prevented from sticking to each other and cannot be woven.
The sizing slurry preparation and sizing process should be strictly controlled during sizing. At present, the domestically produced slurry is mostly acrylate, and the quality has generally passed, but strict selection is required, especially the viscosity and concentration should meet the requirements, and should not be blindly purchased. In order to prevent the antistatic agent on the filament from being removed during the filament process, an appropriate amount of antistatic agent is added to the slurry. In order to maintain the softness of the thread, a certain amount of softener may be added, and an appropriate amount of penetrant and antifoaming agent may be added. In the pulping process, the pulping operation procedures must be strictly followed in order to make the slurry meet the production requirements.
In the production, we must actually follow the requirements of the sizing process, and we must make the “seven-set”, that is, the viscosity of the slurry, the concentration of the slurry, the temperature of the slurry, the speed of the sizing line, the elongation of the fixed wire, and the moisture regain of the fixed wire. Tube or drying room temperature), set the sizing rate. Viscosity is the degree of viscosity of the slurry, and the concentration is the amount of solid glue contained in the slurry. Generally speaking, the two are in the form of a positive yarn, but due to the difference in the quality of each slurry, even the same concentration of the slurry, The viscosity is not the same, so strictly speaking, the two must be controlled. In daily production, some people only control the viscosity, while others only control the concentration. The higher the viscosity and concentration of the slurry, the higher the strength and surface wear resistance of the yarn, and the lower the elasticity, the easier the wire is to be brittle and the more the pulp is dropped, so it must be properly controlled. The speed of the sizing line is too fast, and the production efficiency is high, but the quality of the sizing is deteriorated due to poor penetration of the yarn and poor coating. The warp yarn is generally stretched in the sizing due to the pulling of the roller, the sizing roller and the drying cylinder, but the synthetic fiber such as polyester and nylon is heat-shrinkable fiber, and the silk body passes through the slurry tank, the drying cylinder and the heat. The drying room pulp will produce retraction, so the sizing rate of the combined filaments is generally offset and retracted, the elongation is about 0, the pulp stretch is large, the silk body is elongated, the strength is affected, and the head is easy to break, but the pulp When the stretch is small, the silk body is subjected to the tension of the upper machine during weaving, and will be elongated to destroy the plasma film, and the fiber is easy to fluff. The regain rate of the sizing wire is high, the silk body is easy to be glued, the yarn is not uniformly shrunk, the sling is loose, the hardness is insufficient, and when it is severe, the crack axis is generated, but the moisture regain is low, the static electricity is easily generated, and the fiber fluff is caused, and Because the serosa is hard and brittle, the permeability of the slurry in the silk body is good, and the sizing quality is good. However, if the sizing rate is too high, the pulp will be produced, and even if the sizing rate is small, the silk fiber is easy to be hairy. Therefore, from the practice of production, we must find out the best pulping process and implement it effectively. This is an important measure to ensure the quality and quality of pulp.
At present, the automatic control technology of the pulping machine is high. Only input the required process parameters into the computer monitoring system, it can automatically control and detect online, and the image can be displayed on the infrared touch screen and automatically recorded. The important thing is that the technician needs to input the correct process parameters and press the recorded data. Correct the process parameters in time with the actual situation of production.
Which materials can be directly woven without sizing?
The raw materials for weaving can be divided into two major categories: raw materials (filaments) and weft materials (wefts). Generally speaking, the weft raw materials can be directly processed on the machine without any processing and processing in the water-jet weaving, and the warp yarns are repeatedly pulled by the healds, steel rafts, etc. during the weaving process. The action of stretching, rubbing and bending will cause the mechanical properties of the warp to decrease, and it is easy to form fibers scattered, rubbed, etc., which will cause the warp to affect the smooth progress of the weaving. Therefore, when the non-twisted or low-twisted synthetic filaments are used as the warp yarns, the sizing treatment must be carried out to improve the weaving performance, thereby adapting to the high-speed operation of the loom and ensuring smooth weaving.
So, which warp raw materials can be directly woven without sizing?
According to the fabric requirements and the supply of raw materials, it is possible to directly weave the yarn without the use of the yarn. The free-slurry yarn refers to a type of warp-knitted material which can be directly woven without sizing treatment. The English abbreviation is NOY or NSY.
The free-free yarn mainly includes the following:
Also known as collateral filaments, the multifilaments are blown by compressed air in a network nozzle, causing some of the fibers to partially entangle other fibers at intervals without loosening, thereby forming a strand having network points. When the multifilament passes through the network nozzle under a certain tension and speed, the compressed air is blown in the vertical direction or at an angle, so that the monofilament in the multifilament strongly vibrates, forming misalignment, bending and other single-wire winding, producing periodicity. Locally entangled network points increase cohesion and can be used instead of twisting. When the network wire is woven, it is not easy to produce a broken yarn. The network wire with the network point of more than 150/m can be directly woven without sizing, and the wire-free wire mainly refers to the network wire (co-filament wire). However, if the network is too high, the refractive index of the fabric surface is not uniform, which affects the appearance and feel. In order to improve the woven fabric, it can also be applied to the high-speed water jet loom by applying oiling (waxing) or properly dragging (lightening) during warping.
The wire is twisted, and when the twist is generally 6-8 捻/cm or more, sizing is not required during weaving. However, the number of processing steps increases, the cost increases, and sometimes the quality of the product is affected. In addition to the requirement of warp twisting, the water jet weaving project is generally not suitable for twisting.
3.减少合纤长丝中单丝根数（Reduce the number of filaments in the filaments）
Synthetic filament fabrics require a smooth and full-bodied silk surface and a soft hand. Therefore, it is often desirable to use a multifilament with a plurality of monofilaments and a larger number of raw materials. For example, 77.8 dtex (70 denier) of nylon filaments consists of 16 filaments, 18 filaments, 36 filaments, and 48 filaments. This type of filament yarn often needs to be sizing before being woven on the machine. If the number of monofilaments and the diameter of the multifilament of the multifilament are reduced, if the number of filaments of the nylon filament is reduced to less than 10, the sizing is not required, as long as it is treated by oil or waxing during warping. The shaft can be woven on the machine. However, this method is difficult to use because the number of monofilaments is reduced or the diameter is increased, which makes the fabric hard and has a poor appearance. In particular, polyester filament fabrics are particularly important.