Basic process of humid heat pre-shrinker machine

The basic process of the wet heat pre-shrinking machine is spraying-extruding-drying. According to the different coating materials, it can be divided into two representative equipments: rubber blanket pre-shrinking machine and woolen blanket pre-shrinking machine. Their working principles are different. It adopts the principle of "bending deformation extrusion".

For example, in the structure of the fabric, the three parameters of yarn count, twist and density have a great relationship with the shrinkage rate. The gap between the yarns of the fabric with high warp and weft density is smaller than that of the fabric with low warp and weft density, so the fabric with high warp and weft density is more difficult to shrink than the fabric with small warp and weft density; similarly, the fabric with thick yarn count is also more difficult to shrink than the fabric with fine yarn count.

When the warp yarn density is greater than the weft yarn density, the warp shrinkage rate is greater than the weft shrinkage rate; on the contrary, the warp direction shrinkage rate is greater than the weft shrinkage rate; closer.

The yarn with high twist has a high linear density, and the diameter of the yarn and wire increases greatly after wetting and swelling, resulting in aggravated shrinkage in the length direction and high shrinkage at the machine.

Therefore, there are certain requirements for the moisture supply before pre-shrinking of fabrics of different tissues. The control of the moisture supply directly affects the pre-shrinking effect. The moisture supply is generally controlled between 10%-20%, and 15% for thick and dense fabrics. -20% or so. These situations are the ones that should be paid attention to when using the pre-shrinker in finishing.

https://www.hans-machinery.com/