Stitching is the main means to connect the parts of products. Only by sewing can the scattered parts and components be assembled into a complete product. The sewing process is the main part of the operation process of our cosmetic bag.
Pin code is the concrete embodiment of sewing. In addition to connecting, pin code also plays the role of decoration. It is very common to beautify makeup bags with pin code. In addition, pin code also plays the role of reinforcement. For example, the edge of stitching is stronger than that of non stitching, and the edge of double stitching is stronger than that of single stitching.
In the production of cosmetic bags, machine stitching is the main method. Sometimes due to the limitation of sewing machine function, some stitching must be done by hand.
The basic stitching methods can be divided into four types.
1、 Stubble pressing method
The method of pressing stubble seam is often used in the production process. This kind of sewing method is to first refract the edge of the upper pressing part. The edge of the lower part is marked with stitches and coated with dry agent. The edge of the lower part is chipped with surface layer, and then the edge of the upper part is pressed on the edge of the lower part. The two parts overlap each other. The width of the overlap is determined according to the number of stitches required, which is generally 8 ~ 15mm.
When sewing, the first thread should be sewed first. The distance between the first thread and the edge is 2 ~ 3mm, and the distance between the second thread and the first thread is 5 ~ 12mm. Of course, there are only one stitch or three stitches. How many stitches need to be sewn depends on the product process.
The stubble pressing method is relatively firm, the surface is smooth, beautiful and widely used. This kind of sewing method is often used to sew the leather makeup bag.
2、 Reverse sewing method
Reverse sewing is to sew the two parts on the sewing machine with their faces overlapped. The stitching is on the reverse side of the parts. Before sewing, the thickness of the two parts' edges should be cut evenly, and the edges should be trimmed with a knife.
When stitching, the two parts should be overlapped with each other, and the two edges should be parallel. Then, a seam should be sewed at the edge according to the specified value of sewing allowance. After stitching, the two parts should be expanded vertically or leveled, depending on the process requirements. Sometimes it is necessary to sew a seam on both sides of the seam to make the connection between components more smooth.
Reverse seam method is widely used in the production process of luggage products, especially in the soft structure of the package. The characteristics of this sewing method are: the stitches are not exposed, the stitches can be prevented from being worn out, the joint of the two parts is smooth, the operation is simple, and the efficiency is high.
3、 Rolling seam method
Rolling seam is carried out on the basis of reverse seam. It is generally used for edge rolling of parts.
Before stitching, the thickness of the edge of the parts should be cut evenly, and the rolling strip skin should be cut well. The rolling strip skin has natural color rolling strip and different color rolling strip. The thickness of rolling strip skin should be cut evenly, and the thickness is mostly 0.2 ~ 0.5mm. For example, when thick rolling strip is required, the rolling strip skin should be thicker, and when thin rolling strip is required, the rolling strip skin should be thinner.
When stitching, the surfaces of the two parts cut by the chip are overlapped with each other, and the two sides are parallel. First sew the seam 2 ~ 3mm away from the edge. Then unfold the two parts and fold the roll strip to the opposite side. Apply adhesive on the reverse side of the roll strip, and apply dry agent on the upper side of the reverse side of the part edge, so that the roll strip is dry and firm on the edge, and sew the line on the edge of the front roll.
This kind of sewing method is often used in luggage products, especially in the production of women's leather bags, such as the rolling mouth, the rolling edge, the rolling edge of parts and parts, and so on. This kind of sewing method is characterized by round, smooth and firm edges.