Case 3 :how to properly use the differential lockstitch sewing machine?

As shown in Fig. 1, the lower layer fabric is a kind of four-side elastic knitted fabric. To add the weaving or knitting pleating process to this fabric, the upper and lower differential flat sewing machine is required. Since the lower layer fabric will stretch and the material cannot be fed, it is necessary to use a machine with a lower differential function to pull the fabric in advance, so that the material feeding will be smooth and the stitch pitch will be normal; The upper differential function of the machine shall be used when the upper fabric needs lace pleating, and the fabric shall be grasped in large proportion to complete the two processes of lace pleating and sewing at one time.

In addition, for the thicker upper and lower fabrics with feeding difficulties (as shown in Fig. 2), the upper and lower differential lockstitch sewing machine can also be selected to facilitate the adjustment. Of course, the structure of the upper and lower differential sewing machine is more complicated than that of the single differential sewing machine, and the cost is also higher.

In the garment processing process, there are often special sewing requirements for different parts, such as women's clothing and performance clothing. One section needs to be a flat seam, and the other section needs to be pleated. Some of these are the process requirements of the upper fabric, and some are the process requirements of the lower fabric. At this time, the lockstitch sewing machine is required to have the intelligent sewing function of section counting and quick adjustment of the differential amount of each section. It is generally used for women's clothing, upper sleeve folding, shirt dovetail hem, and other processes, as shown in Figure 3, figure 4, and figure 5.

Smart sewing usually has a visual touch operation screen, which is convenient for quick setting and has the function of pattern storage, as shown in Figure 6.