Take out the socks and pull out the bottom line about10 cm;

Replace qualified parts as required, adjust the height and position of needle bar, the distance and gap between needle and shuttle tip;

Chemical fiber thread should be cooled by machine needle (silicone oil);

The sewing speed should be slowed down to increase the smoothness of the upper thread;

Adjust the matching time of tangent cam;

According to the sewing material, the presser foot can be moved to the left or right, or the narrow groove can be opened after the wide groove is filled with solder, and the qualified presser foot can be polished or replaced.

Classification of sewing machines

(1) sewing machine is a machine for sewing plastic woven bags (objects), paper bags (objects), paper-plastic composite bags (objects), aluminum-plated paper bags, etc. Mainly used for splicing and sewing bags or woven fabrics. The process is characterized by good sealing after sewing, such as leather bag; High strength, such as cement bag; Easy to disassemble, find out the thread end is loose, and the bag can be reused

② The general mode is GK. GK series industrial sewing machines are imported from DS series of Newland Company of Japan and American ones. There are two kinds of single-thread chain and double-thread chain according to stitch, single-thread chain and double-thread chain according to stitch number, and desktop sewing machine, portable sewing machine and vertical sewing machine according to use. Domestic portable sewing machines are mainly GK9 series, which have been used for many years. In addition, domestic portable sewing machines are copied from Japan and Germany. Foreign brands are NP series of Newland, Japan, with single-line carrying and double-line carrying. GK35 series is the most popular vertical sewing machine in China. It is an imitation of German products, belonging to low-end products, while the high-end ones are made in Japan.

operation requirement

Hand-operated sewing machine is flexible and simple, but the labor intensity of workers is high and the productivity is low. Because it is a single thread, the strength after sewing is low. Once the thread is continuous or poorly stitched, the bag mouth will open. Vertical sewing machine should form an assembly line with conveyor and cooperate with it. In a highly automated factory, sewing machines should also cooperate with packaging scales, folding machines, inkjet printers and palletizing devices. It can realize high-speed, unmanned and highly automated weighing and packaging.

Key points of operation

(1) threading: thread the upper thread and the bottom thread in the specified order, otherwise sewing failure, broken thread or jumper will be caused;

(2) Tension of thread: The tightness of thread is an important aspect of sewing success. Improper adjustment will lead to thread breakage, needle jumping and bag tearing. The tension regulator of heavy materials (such as sacks) is slightly relaxed; Tension regulator of light material tension line; Adjust the feed speed according to the difference of needle distance and bag thickness; When adjusting the tightness of needle and thread, the tightness of bottom thread must be adjusted accordingly.

(3) Foot pressure: If the reverse side of the sewing thread looks like a trace cut by the cloth feeder, or the actual needle distance is less than the preset cloth feeding speed of the cloth feeder, it means that the pressure is too great, and then the needle plate spring adjusting screw should be loosened; If the suture is not straight or uniform, tighten the needle plate spring adjustment screw to increase the pressure; In addition, the pressure decreases when sewing heavy materials such as sacks, and increases when sewing light materials such as plastic woven bags.

(4) Adjustment of bending needle: rotate the pulley forward and adjust the crank, so that when the needle is at the maximum retraction position, the bending needle breaks at 7mm from the center line of the needle;

(5) Adjustment of the cloth feeding mechanism: ensure that the cloth feeding teeth do not touch the needle plate when passing through, and there should be a gap of 1.5mm between the middle teeth of the front cloth feeding teeth and the needle plate; The rear feeding teeth are lower than the front feeding teeth by 0. 1mm, and the stitch width can be adjusted within the range of 7mm to 1 1.5mm as required; When the stitch width changes, the gap between the needle guide plate and the needle will also change, so the needle guide plate must be adjusted accordingly.

(6) Adjustment of scissors: In order to make the upper/lower blades bite, manually move the upper blade, and when the two blades bite, adjust the gap at the ends of the two blades to 0.1-0.2 mm. ..