What causes the shrinkage rate of the fabric? With common fabric shrinkage rate

The shrinkage of the fabric is a common change in the shrinkage of the fabric after the textile has been washed, shaken, and dried. Most textiles have different degrees of shrinkage, and this also reflects another advantage of non-woven fabrics, because non-woven fabrics are non-woven fabrics, so they do not contain shrinkage. When people buy fabrics, they only require the shrinkage rate to reach a certain shrinkage value, and no one will require zero shrinkage. It is not that the higher the temperature, the better. For synthetic fibers, high-temperature ironing will not only improve its shrinkage, but will damage its performance, such as the hard and brittle fabric. Choosing a suitable ironing temperature according to the composition of the fabric can also improve the shrinkage of the fabric. For example, cotton and linen fabrics can be ironed at a high temperature to improve their size shrinkage. Among them, the drip drying method has the least impact on the size of the fabric, while the drum arch drying method has the greatest impact on the size of the fabric, and the other two are in the middle. Commonly used drying methods include drip drying method, metal mesh tiling method, hanging drying method and drum drying method. 1. Factors affecting the shrinkage rate of fabrics. 1. Washing care process. The drying method of the sample has a relatively large impact on the shrinkage of the fabric. For example, the dimensional stability of hand-washed samples is better than that of machine-washed samples, and the washing temperature will also affect its dimensional stability. Generally speaking, the higher the temperature, the worse the stability. Washing care includes washing, drying, and ironing. Each of these three steps will affect the shrinkage of the fabric. 2. Production process. In the actual process, we generally use pre-shrinking to solve this problem. However, it is easy to release the tension of the fabric after it encounters water, so we will find that the fabric shrinks after washing. As the fabric is inevitably stretched by the machine in the process of dyeing, printing, and finishing, there is tension on the fabric. 3. Fabric structure. In the knitted fabric, the shrinkage rate of the plain stitch is smaller than that of the rib fabric. Among woven fabrics, the shrinkage rate of plain weave fabrics is generally lower than that of flannel fabrics. In general, the dimensional stability of woven fabrics is better than that of knitted fabrics; the dimensional stability of high-density fabrics is better than that of low-density fabrics. 4. Fiber composition. Wool is easily felted due to the scale structure on the fiber surface, which affects its dimensional stability. Natural plant fibers (such as cotton and hemp) and plant regenerated fibers (such as viscose) are compared with synthetic fibers (such as polyester and acrylic). It is easy to absorb moisture and expand, so the shrinkage rate is relatively large. 5. Production process. Generally speaking, in the process of weaving, dyeing and finishing of the fabric, the fiber has to be stretched many times, and the processing time is long. The shrinkage rate of the fabric with greater applied tension is greater, and vice versa. Different production processes have different shrinkage rates of fabrics. 6. Thickness of yarn count. Fabrics with thick yarn counts have a higher shrinkage rate, and fabrics with fine yarn counts have a smaller shrinkage rate. Different yarn counts have different fabric shrinkage rates. 7. The density is different. A fabric with a weft density greater than a warp density will shrink in the weft direction. Fabrics with high warp density will shrink more in warp direction. If the latitude and longitude density are similar, the shrinkage rate is also close. 8. Raw materials. Some viscose fibers have a water absorption rate as high as 13%, while synthetic fiber fabrics have poor moisture absorption and their shrinkage rate is small. Generally speaking, for a fiber with high moisture absorption, the fiber expands after being immersed in water, the diameter increases, the length decreases, and the shrinkage rate is large. Different raw materials have different shrinkage rates of fabrics. 2. Reasons for fabric shrinkage 1. Fiber is closely related to the textile processing and the dimensional stability of the fabric, which provides some basis for the design of subsequent processes. For example, the boiling water shrinkage rate of processed polyester staple fiber is 1%, the boiling water shrinkage rate of vinylon is 5%, and the hot air shrinkage rate of chlorinated fiber is 50%. The fiber performance is different due to the internal structure, heating temperature, time and other conditions. There is also a steam method to measure the percentage of shrinkage in steam above 100°C. The hot air method is also used to measure the percentage of shrinkage in hot air above 100°C. The percentage of length before heat shrinkage and after heat shrinkage is called heat shrinkage rate. Generally, it is measured by boiling water shrinkage test. In 100℃ boiling water, the percentage of fiber length shrinkage is expressed. When the textile fiber is heated, the shape and size of the fiber will change and shrink, and it will not return to the initial state after cooling, which is called fiber thermal shrinkage. 2. The synthetic fiber shrinks to heat, such as boiling water shrinkage, generally about 5%. Cotton fiber expands under the action of water, the cross-sectional area increases by 40-50%, and the length increases by 1-2%. On the fabric, the fiber curvature radius of the interweaving point of the fabric is forced to increase, resulting in the shortening of the fabric length. When the fiber is in a wet state, it will expand due to the action of the immersion liquid, making the fiber diameter larger. 3. The degree of shrinkage of hydrophobic fibers is less, such as synthetic fibers, such as cotton, linen, viscose and other fibers. Different fibers and fabrics have different degrees of shrinkage, which mainly depends on the characteristics of their fibers-hydrophilicity The shrinkage of the fiber is relatively large. 4. The release of internal stress in different degrees makes the yarn fiber and fabric return to the initial state, in the static dry relaxation state, or the static wet relaxation state, or in the dynamic wet relaxation state and the full relaxation state. At the same time, the yarn fiber and fabric structure generate internal stress. When the fiber is spinning, or when the yarn is weaving, dyeing and finishing, the yarn fiber in the fabric is stretched or deformed by external force. The above is about the reasons for the shrinkage rate of fabrics and the related content of common fabric shrinkage rates. If you have any questions, please contact the relevant personnel of our company directly.