1. Material selection: Because underwear is in direct contact with the skin, material selection must be very particular, usually considering whether there are harmful components, hygroscopicity, antistatic property, skin touch, perspiration fastness and washing fastness (color fastness) of dyes, elasticity and strength of fabrics, etc. Because natural fibers are superior to chemical fibers in moisture absorption, skin touch and antistatic property, and knitted fabrics are superior to woven fabrics in elasticity, knitted fabrics of natural fibers are mostly used for underwear lining. In order to increase the elasticity of fabrics, high elastic fabrics lined with spandex are usually used.

Harmful ingredients mainly refer to harmful chemicals left in the dyeing process of fabrics, which are easily absorbed by the skin during wearing; Moisture absorption mainly refers to whether the human body can be effectively absorbed after sweating, and it is easy to cause bacterial infection if it is in a state of poor moisture absorption for a long time; Poor antistatic performance and poor touch to the body and skin will make you feel uncomfortable during wearing; The fastness to perspiration and washing of dyes is not good, which is easy to cause dye molecules to fall off or even be absorbed by the skin during wearing, leading to diseases; The elasticity and strength of cloth affect its comfort and durability.

2. Sticking cloth: Sticking cloth is to stick the cloth and sponge together with adhesive. The surface of the cloth after sticking must be flat, and the adhesive and its solvent harmful to human body, such as adhesive containing formaldehyde and acetone, cannot be used in the process of sticking cloth, otherwise, these components will affect human health if they remain in the clothing.

3. Cutting: Generally, typesetting is first followed by cutting. In typesetting, attention should be paid to the grain of the fabric and reasonable arrangement should be made according to its performance. If the grain directions of the left and right pieces are different, the elasticity of the left and right back pieces of the finished product will be different, and the tightness of both sides will be different when wearing; In the process of sewing, it will also have different sizes, which will affect the appearance.

Generally, a long shoulder strap is cut to a certain length according to the requirements, then the shoulder strap buckle is put on and sewn with a single needle zigzag sewing machine. Or sew with a tying machine; In the use of invisible shoulder straps, we must ensure that they have considerable elasticity and sufficient strength to prevent them from breaking and falling off. At the same time, pay attention to the selection of suitable needles in the sewing process to prevent the rubber thread from sticking out.

4. middle bowl combination: two pieces of outer bowl cloths are fixed in radian with a single-needle lock stitch flat car, with a general seam of .5cm, and sewn in series. For the middle bowl cover line, a series of sewn pieces of cloth are pulled out by a special presser foot on both sides, and then fixed by a double-needle lock sewing machine. This process requires that the tension between the double needle top thread and the bottom thread is moderate, and the appearance cannot be affected.

5. Sponge combination: sew the sponge pieces with a single-needle four-point zigzag sewing machine, and fix both sides of the sponge with cloth strips. Sponge sheets must be closely combined with each other, and operators should sew along the curvature of sponge sheets when sewing. And the tension between the top thread and the bottom thread should be consistent and the tightness should be moderate. Otherwise, the three-dimensional effect of the sewn sponge bowl is poor.

6. Combination of inner and outer bowls: fix the sponge inner bowl and the cloth outer bowl with a single needle sewing machine, and the stitches in the inner and outer bowls must be aligned, otherwise the bowls will be deformed and the appearance will be affected. On the spine, that is, fold the spine piece in half and copy the edge with a three-line sewing machine. Lace is combined with the upper

spine, and the spine and lace are fixed by a single-needle herringbone lock stitch sewing machine. The straight edge of lace must be aligned at the sewing bowl, and the spine is only fixed on the lace, and it should be sewn along the arc as close as possible to the edge of lace.

7. Combining the upper spine with the bowl: combine the lace with the bowl cloth with a single-needle flat sewing machine, and do not sew on the lace. Overlap the bowl .5cm on the spine piece, sew it in the center of the overlapping seam, and the head and tail should be even, and the seam should not wrinkle.

8. Fix the lace and the bowl cloth and sew them on the outside. Both the inside and outside of the lace belt should be tightly wrapped, and the seam should be flat and not wrinkled.

9. Center sewing: fix the cloth at the spine center with a single-needle flat sewing machine, with a seam of .4cm, and align it up and down.

1. Sew the cover line in the center, pull out and align the last sewn piece of cloth with a double-needle lock machine and a special presser foot, and add cloth strips on it.

11. The spine is combined with the center, and the inner and outer pieces of the spine are fixed with a single-needle flat sewing machine, without wrinkling, and the seam is .4cm.

12. Combine the lower spine with the bowl, fix the spine cloth and the bowl cloth with a double-needle sewing machine, and add cloth strips under it. Fold the spine cloth by .6cm, fold the cloth strip at the middle corner, align it, and sew it to the bowl with double needles.

13. Wrap the upper swing, mark and fold the shoulder strap head, use a two-needle flat sewing machine, and wrap the inside and outside tightly with cloth strips. The shoulder strap head should be sewn 1cm. During sewing, the sewn upper swing should be checked by hand, and the thread should not be broken. Otherwise, suture breakage may occur during taking, such as strenuous exercise or sneezing by the user.

14. The spine center is combined with the bowl and spine center, and the seam is .6cm with a single needle sewing machine, and the top and bottom should be aligned.

15. sewing the left and right cover lines: sew the seams outward with a margin of .1cm, use a double-needle sewing machine, fold them upside down and sew them upside down, add cloth strips to reinforce and decorate them, and add film as needed to increase their wearing function.

16. Add elastic band to the hem: the first line overlaps by .6cm, the second line is sewn by the side, and the two lines are grasped by both hands with a length of 1cm in the sewing process. If you pull the cloth to the limit, it should not be broken, otherwise it will affect the wearing and taking.

17. Sewing of shoulder strap head: thread the buckle ring, fold the shoulder strap head and fix it with a single needle zigzag sewing machine. Back belt, tight * belt with side seam, the needle can not be sewn to the back, the upper end of the needle is reversed, and it is adjusted according to the width of the hook.

18. Hooks: two rows of hooks on the right, with the trademark inserted in the center, with the inner edge of .1cm and the outer edge slightly covered. The back piece should be inserted as far as possible, but not protruding, so as not to affect the appearance. Adopt a single needle zigzag sewing machine, sew in series before cutting, check a hook for each one, and be careful that needle cutting cannot occur.

19. Small hooks: two rows of hooks on the left, with the inner side near the edge and the outer side slightly covered with the back sheet. The back sheet should be inserted into the small hooks as much as possible, and then cut after sewing in series with a single needle zigzag sewing machine.

2. Sewing of large and small hooks: use a single needle zigzag sewing machine to sew in series before cutting. Sewing stitch should be smooth and level, and the joint between top thread and bottom thread should be in the center of the side. Nail flowers and cards, and nail them in the designated position as required. Inspect the packaging as required.