How to correctly use the differential lockstitch sewing machine? Case 1

Our previous knowledge "teach you how to choose a high-quality differential lockstitch sewing machine" initially introduced the performance and characteristics of a high-quality machine. for the equipment market and user enterprises, this professional knowledge about the differential flat sewing machine is far from enough. Because there are many varieties of machines, there are four major series, such as platform type, cylinder, chain type, and cutter carriage. At the same time, it is subdivided into nearly 40 subdivided varieties, such as the upper differential, lower differential, and upper and lower differential.

How does the equipment user enterprise choose the machine that is suitable for their actual production process needs and how to maximize the performance of the machine? This article will take you to learn more about problems caused by poor use of the special features of the differential sewing machine in garment processes and the correct solutions.

Let's first look at how to solve the problems caused by the upper fabric.

Fig. 1 upper layer fabric feeding is too slow

The sewing direction must be confirmed before sewing. As shown in Figure 1, the lower layer fabric is flat, and the upper layer fabric has obvious material catching (the feeding speed is too slow). It is enough to solve the feeding problem of the upper layer fabric. This problem can be solved by selecting a differential flat sewing machine with an upper differential function and quickly adjusting the stroke trajectory of the feed presser foot.

The brand differential lockstitch sewing machine generally has an intuitive differential adjustment knob (see the above figure for reference), which can intuitively and quickly locate the differential value of the travel path of the feed presser foot. for example, when the scale value of the needle distance knob is 2, the feeding of the upper layer in Fig. 1 is slow. When it is necessary to speed up the feeding of the upper layer, it is only necessary to rotate the blue differential adjustment knob in the direction of "+" and adjust the differential scale to the range of 2.2 ~ 2.5, which can obviously improve the twisting condition of cloth catching.

Figure 2 upper layer fabric feeding too fast

On the contrary, if the upper layer fabric in Fig. 2 moves too fast and causes twisting, just rotate the blue differential adjustment knob in the direction of "-" and adjust the differential scale to the range of 1.8 ~ 1.2 to improve the twisting. Don't underestimate this traditional adjustment knob mechanism, which is a great love of sewing workers. It can often work more intuitively and efficiently in sewing. As long as we can identify the factors that cause the twisting problem and rotate the knob easily and quickly, we can make high-quality clothing products.

For a specific application, let's take a look at the aesthetic problem of zipper placket sewing, which is directly related to the quality of clothing.

Let's first learn about the placket pressing process: the body fabric (three layers) is at the top, and the sewn four layers of fabric (zipper + body) are at the bottom. We need to press a placket thread on the zipper.

According to the normal feeding mode of the ordinary lockstitch sewing machine, the upper layer fabric (extremely thin and soft) is easy to be pressed due to the resistance of the pressure foot. In addition, the zipper process requires that the garment body has been closed for about 1 inch, which is more likely to cause cloth pressing and obvious twisting. At this time, we need to use the differential flat sewing machine to evenly collect the upper fabric and press it onto the zipper in advance to complete the high-quality thread pressing process, as shown in Fig. 3 and Fig. 4.