Technical treatment of leather sewing

1. Machine needle, sewing thread, and sewing needle pitch density:

The sewing needle pitch density of leather clothing and the selection of machine needles should be determined according to the properties of sewing materials.

Generally, 16 ~ 18 machine needles are used, When the leather is very hard and thick, the machine needle larger than 18 can also be selected, but the diameter of the needle plate hole should be increased accordingly, otherwise, there will be wire breakage or jumper. During sewing, because too dense stitches will damage the structure of leather, the density of sewing needle pitch is usually 9 ~ 12 stitches / 75px and that of decorative sewing is 6 ~ 9 stitches / 3cm. It is better to use a silk machine to sew silk thread No. 20; Size 16 ~ 18 for a decorative seam.

2. Sewing skills:

Domestic sewing machines and industrial sewing machines can be used for the sewing of leather clothing. When sewing, the presser foot of special leather material shall be used; In addition, in order to solve the problem of the poor trend of leather on the machine, the electrical paper with a thickness of 0.5 ~ 0.8 and good toughness can be cut into long strips of 1 ~ 1.5 widths. When sewing, it can be padded under the half presser foot, which can play the role of auxiliary feeding; In addition, it can also adjust the eating trend of upper and lower materials and assist in sewing straightness. Glue the seam with rubber paste or special glue for leather at the seam, and then knock the ingredients with a hammer to open the seam or sit down the seam according to the process requirements.

3. Leather finishing:

Before cutting the leather, the leather plate should be sorted and leveled. For slight unevenness, it can be gently pulled directly, horizontally, or obliquely; Serious wrinkles should be ironed, but the ironing temperature should be low, and the iron should stay in the same part for a short time. Ironing should be carried out on the reverse side of the leather as far as possible. If you must iron on the front, you can pad a layer of kraft paper on the leather surface to prevent damage to the leather surface.