underwear material selection, cloth sticking, cutting, shoulder strap cutting, shoulder strap making, middle bowl combination, middle bowl cover line, sponge combination, inner and outer bowl combination, upper spine center, lace and upper spine center combination, upper spine center and bowl combination, fixed lace and bowl part, center seam, center seam cover line, spine center combination, lower spine center and bowl combination, and upper edging. 1. Material selection. Because underwear is in direct contact with the skin, the selection of materials must be very particular, usually from the presence or absence of harmful components, hygroscopicity, antistatic property, skin touch, dye perspiration fastness and washing fastness (color fastness), fabric elasticity, strength and other aspects to consider. 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 the harmful chemicals left in the dyeing process of cloth, 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, sticky cloth. Sticking cloth is to stick cloth and sponge together with adhesive. The surface of the cloth after sticking must be smooth, and adhesives and solvents harmful to human body, such as adhesives 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 cloth. 3, it is 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 into a certain length according to the requirements, then the shoulder strap buckle is put on and stitched 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. The middle bowl is combined, and two pieces of outer bowl cloth are fixed according to the radian with a single-needle lock stitch flat car, with a general seam of .5cm, and sewn in a string. 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. Combine the inner and outer bowls, and fix the sponge inner bowl and the cloth outer bowl with a single-needle flat sewing machine. 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. The lace is combined with the upper spine, and the spine and the lace are fixed by a single-needle herringbone lock stitch sewing machine. The straight edge of the 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 the lace. 7. Combine the upper spine with the bowl, and combine the lace with the bowl cloth with a single-needle flat sewing machine. Do not sew on the lace. Overlap the bowl part by .5cm on the spine piece, sew it in the center of the overlapping seam, with the head and tail flush, and sew it flat without wrinkling. 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 sewing should not wrinkle. 9, center sewing, the spine part of the cloth with a single needle sewing machine fixed, seam .4cm, up and down need to be aligned. 1. Sew the cover line in the center. Pull out and align the last sewed piece of cloth with double-needle lock machine and special presser foot, and add cloth strips. 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 shoulder strap on the upper swing, fold the shoulder strap head according to the mark, use a two-needle sewing machine, wrap the inside and outside tightly with cloth strips, and sew it flat without wrinkling. The shoulder strap head should be sewn 1cm. During sewing, the sewn upper swing should be inspected 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 flat sewing machine, and the top and bottom should be aligned. 15. Sew the cover line on the left and right, with the seam outward with a margin of .1cm. Use a double-needle flat sewing machine to fold it upside down and sew it upside down, and add cloth strips to reinforce and decorate it. If necessary, film can be added to increase its wearing function. 16. Add elastic band to the hem. The first line overlaps by .6cm, and the second line is sewn at the side. In the sewing process, the two lines grab the length of 1cm with both hands, and the line should not be broken when the cloth is pulled to the limit, otherwise it will affect the wearing and taking. 17. Sewing the shoulder strap head, thread it into 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. Hook, two rows of hooks on the right, insert the trademark in the center, with the inner edge of .1cm and the outer edge slightly wrapped. The back piece should be inserted as far as possible, but not prominent, 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 inside near the edge and the outside slightly wrapped with the back piece. The back piece should be stuffed into the small hook as far as possible, and the sewing machine should be zigzag with a single needle, and then cut after sewing in series. 2, the size of the hook lock edge, with a single needle zigzag sewing machine, sewing in a string 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.