In the sewing process, wrinkling or shrinkage often occurs, especially in the lower layer of the fabric, if you do not pay attention, often a line to the end of the car, the original length of the two pieces of cloth, actually turned into the following a lot shorter . This phenomenon occurs in particular during the process of sewing fine fabrics, finished fabrics, and thin, non-stretch fabrics.
The wrinkling phenomenon occurs because when the sewing direction is parallel to the warp direction of the fabrics, the embedded stitches force the warp yarns away from the original position because the stitches push the warp yarns through each stitch, passing through multiple stitches. Deviations resulting from the accumulation will shrink along the body of the seam and cause the seams to wrinkle. When the sewing direction is parallel to the weft direction of these fabrics, there is usually less wrinkling. Experience has shown that diagonal seams in the diagonal corners do not wrinkle. Most fabrics, provided that the seams are at a 15 degree angle of latitude or longitude, are sufficient to avoid wrinkling. Therefore, you can consider using oblique cutting mode. If necessary, apply a smoothing agent to the fabric.
In addition, fine needles should be used as much as possible. Since the fine needle can significantly reduce the resistance generated when passing through the fabric, there is an effect of preventing the crease from wrinkling, and it is necessary to pay attention to changing the new needle frequently.
When using a synthetic sewing thread, the tension of the thread must be carefully determined and the tension should be adjusted to a minimum. The tension of the bobbin thread must be adjusted so that when the free end of the thread is pulled up, the bobbin and bobbin of the bobbin thread slowly slide downwards, the tension between the bobbin thread and the bobbin thread must be the same, so that they just interweave between the two layers of fabric. If the synthetic sewing thread is sewn into the fabric with too much tension, it will automatically shrink to relieve this tension. This phenomenon will shrink the body of the cloth along the seam and cause the seam to wrinkle.
The reason why the lower fabric mentioned above is shortened is that the friction between the upper fabric and the presser foot forces the lower fabric on the feed dog to move more quickly, resulting in wrinkling of the seam. The pressure of the presser foot can be lowered as much as possible. At the same time, the feeding teeth (conveyor) with fine teeth can be used to reduce the speed of the sewing machine so as to avoid wrinkles caused by feeding. The best way to solve this problem is to use Differential feeding or needle feed mechanism sewing machine. Of course, if an ordinary sewing machine is used, as long as the sewing machine applies a certain pulling pressure to the lower fabric during the sewing process, the wrinkling phenomenon of the fabric can be significantly improved.