Automatic ribbon pre-shrinking machine, the purpose of shrinking the fabric after weaving and dyeing and finishing in the shape of an unstable state, there are potential shrinkage, if such a fabric garment, less because of the length of the wash after Jingxi shrinkage deformation aliasing, bringing losses to consumers. Thus, the fabric should be shrink-proof finishing, shrink-proof fabric finishing two kinds of methods, including chemical and mechanical finishing. Currently, our pre-shrinking machine is a mechanical sorting machines. The main role of pre-shrinking machine is using mechanical - physical methods to adjust the fabric warp shrink to eliminate contraction of the fabric, while the fabric feel and luster improved to a certain extent. 2, the machine structure and principles into the fabric includes means to me wet, rubber blanket shrinking cloth unit, blankets drying unit, cooling rolls and drop cloth unit. Fabric shrinkage principle, not shrink relationship proved most fabric shrinkage and internal stress fibers and yarns are the cause of, the fabric was found that the main reason for shrinking fiber moisture after all the swelling caused due to the fabric yarns showing a curved state, and therefore, the fabric is greater than the total length of the yarn length of the fabric, the greater the degree of bend line yarn, fabric shrinkage greater. Pre-shrinking machine works: the fabric fed through a damp cloth to stand back to me (Give me wet that is, to improve the wet spray and steam through the fabric moisture content, so that cotton fiber swelling, is conducive to fabric shrinkage) fabric through to Wet into backing roll known as the rubber blanket, rubber blanket action principle: the fabric is treated with a rubber outer arc AB into the backing roll, outside the arc AB into A1B1, in this process, the fabric is not allowed to slide, while not wrinkle because of the length of the arc AB is greater than the length of the arc A1B1, fabrics must be contracted with the contraction of the rubber, so that the degree of bending of the yarn is increased, so as to achieve the effect of contraction. After the fabric pre-shrinking rubber blanket, the blanket drying drop cloth, blankets because larger friction to prevent excessive tension due to side again stretched the fabric. And our company's pre-shrinking machine is mainly through ratio adjustment to achieve the ultimate fabric shrinkage control. Ratio is the ratio of the speed of the rubber blanket cylinder drying speed when greater the ratio, the speed ratio that is drying cylinder rubber blanket faster the speed, the more lead to the fabric of the rubber blanket stretched, leading ultimately shrink the fabric rate decreases. On the other hand, will lead to the final fabric shrinkage becomes large. Through the fabric shrinkage principle and most critical step of shrinking influence understanding, the ultimate goal is to improve the ability of the fabric to shrink law summary and analysis, and thus be able to accurately and quickly control the shrink.