The hot and humid pre-shrinking machine can help the user to obtain a stable fabric size, improve the feel and feel of the fabric at the same time, and make the fabric reach a certain weight and stiffness requirements. The objects to be processed are cotton, hemp, silk and viscose and other cellulose fibers. Fabric-based. The characteristics of such fabrics are that they have high hygroscopicity, and the fibers are apt to swell to shorten the length of the fibers, thereby affecting the dimensional stability of the fabrics and blend fabrics using them as raw materials.
Hot and humid pre-shrinking machines can achieve the above-mentioned objectives after spraying, squeezing, drying and other treatments on such fabrics. According to different coating materials, they can be divided into rubber blanket pre-shrinking machines and felt blanket pre-shrinking machines. Representative equipment, but their working principle is the same, all adopt the bending deformation extrusion principle.
Facts have proved that in the tissue structure of the fabric, the three parameters of yarn support, twist, and density have a great relationship with the preshrinkage rate of the damp heat shrinking machine. The gaps between the yarns with high latitude and longitude density are smaller than the ones with smaller latitude and weft density. Therefore, the fabrics with high latitude and longitude density are harder to shrink than the fabrics with smaller latitude and weft density; similarly, the coarse yarns are also harder to shrink than the fine yarns.
Therefore, there is a certain requirement for the moisture content of the fabric before the shrinkage of different fabrics. The control of the moisture content directly affects the preshrinkage effect. The moisture content is generally controlled between 10% and 20%, and the thick fabric is 15%. -20% or so, these conditions are pre-cautious for garment factories using pre-shrink machines.
Another point is that the unsynchronized control of the pre-shrinking machine can cause the fabric to stretch or wrinkle during pre-shrinkage, which greatly affects the pre-shrinking effect. Therefore, in the design of the damp heat shrinking machine, the synchronous automatic control of each unit is emphasized, the stability of the operation of the shrinking machine can be improved, and the pre-shrinking quality of the product can be ultimately improved.