What is shrinkage?

The yarn has buckling in the process, so its length or width in the fabric must be less than its original straight length. The percentage that reflects the difference between the two is the weaving shrinkage, referred to as the weaving shrinkage. or weaving. They are expressed in terms of warp shrinkage and weft shrinkage, respectively.

The reason for the shrinkage

The weaving yarn is a unisexual material. Before the warp and weft yarns are interwoven into a fabric, they can be in a straight state under a certain tension. However, during weaving, the warp and weft yarns stagger with each other, and the yarns change from the original straight state to In the wave buckling state, the length is shortened, thereby forming fabrics with different structures, so that the length of the woven fabric is shorter than the original length of the yarn to form weaving shrinkage.

The root cause of shrinkage is due to the buckling of warp and weft yarns. The main reason for determining the weaving shrinkage of the yarn in the fabric is the number of warp and weft yarn interlacing and the degree of buckling wave.

Weaving shrinkage affects the strength, thickness, density, weight, appearance and shrinkage rate of the finished product. Due to the difference in the raw material thickness, density, fabric structure and process parameters of the warp and weft yarns, the warp and weft yarns can have a variety of matching relationships, so the weaving shrinkage rate is also different.

The larger the shrinkage of the fabric, the more raw materials are used. On the contrary, the smaller the shrinkage of the fabric is, the less the raw materials are used.

Main Factors Affecting Fabric Shrinkage

1. Ingredients

The influence of fiber raw materials on weaving shrinkage is more complex. Generally speaking, yarns that are easy to buckling have a large weaving shrinkage; yarns that are prone to plastic deformation have a small weaving shrinkage.

2. Yarn fineness

When warp and weft yarns with different linear densities are interwoven, the higher the linear density, the less easy the yarn is to flex, and the smaller the weaving shrinkage rate; in the fabric with the same warp and weft yarn density, the weaving shrinkage rate of the high linear density yarn fabric is larger.

3. Yarn twist

If the twist is large, the yarn structure is tight and the stiffness is large, the shrinkage performance is poor and the shrinkage rate is small, otherwise, the shrinkage rate is large.

4. Average float length

The more weaving points of the fabric, the smaller the average float length, the more warp and weft buckling waves, and the greater the weaving shrinkage.

5. Fabric density

The tighter the fabric, the more warp and weft buckling waves, and the greater the weaving shrinkage of the fabric.

6. Weaving process

Tension and opening time on the machine: The tension and opening time on the machine directly affect the shrinkage rate of the fabric and the weft density of the grey fabric. When the tension on the machine is large, the opening time is early, and the warp buckling wave is small, so the warp shrinks and the weft shrinks greatly; on the contrary, when the tension on the machine is small, the warp is easy to bend, and the warp shrinks and the weft shrinks.

7. Influence of sizing rate

Sizing: When the warp sizing rate is high, the warp shrinkage decreases, and vice versa.

8. Temperature and humidity in the weaving workshop:

Temperature and humidity: The temperature and humidity in the weaving workshop are high, and the warp yarn is easy to stretch after being subjected to tension, so the shrinkage decreases and the shrinkage increases; on the contrary, the warp shrinkage increases and the weft shrinkage decreases.