Introduction to the shoemaking process

Introduction To Shoe Components, Injection Molding, Cold Bonding Processes, Etc.

The composition of shoes is divided into two categories: injection molding and cold bonding.

Injection molding is the shoe made by the machine. After the upper is tied to the aluminum last, the turntable machine directly injects PVC, TPR, and other materials to form the sole at one time. Now there is also PU (chemical name polyurethane) injection molding (The machine and the mold are generally the same. The injection molding is not the same).

Advantages: Because it is machine-made, the output is large, and the price is low.

Disadvantages: If there are many styles, it is more troublesome to change the mold, the shoes are difficult to shape, and the cold glue shoes are not exquisite, so they are generally suitable for orders with a single sole style.

Cold, sticky shoes are often said to be handmade. Italian and Spanish brand-name shoes belong to this category. Generally, cold-adhesive assembly line processing is required (except for family workshops). Cold-adhesive soles are generally provided by factories specializing in shoe soles. If they do not have sole molds, they need to open additional molds. Generally, shoe sole factories are free to open molds for more than 10k pairs. The method uses plastic last to shape the upper surface and glue it together with the sole.

Advantages: The quality is fine, and the shoes made are better. Disadvantages: The daily output is small, the price is high, and it is generally suitable for medium-sized factories to form a scale.

Differentiation method: The most noticeable feature of the difference between cold glue and injection molded shoes is the sole. The injection-molded shoes have a line on the heel or edge because the shoes are left from the mold. The cold-adhesive sole is on the side where the upper and sole are glued, invisible.

The components of shoes: mainly composed of upper, inner lining (lining), front and back ironing bottom, front and back toe caps, midsole (also called inch bottom), sole, and other parts.

Upper: The materials generally include LEATHER or artificial leather. The leather materials are uneven, and the best is, of course, the first layer of leather, which is soft and has good flexibility. Generally speaking, shoes made of high-quality Nappa leather are better. There are many kinds of artificial leather. The most are PU leather, and the thickness is in the unit of silk, generally 800 microns, good can reach 1400 microns, suitable for the production of single-layer upper (non-composite lining), comfortable to wear, especially in Korea Shoes, generally do this. In recent years, the popular PU leathers include rubber rubbing leather, rubbing leather, bubble pattern, crazy horse pattern, large and small pattern, napa pattern, R8 pattern, 18 pattern, and many other patterns. Crazy horse leather has a texture like genuine leather and has sound effects, so it is trendy, but the price is very high. Glue rubbing is the most classic leather. It has been popular for more than ten years. Now there are many kinds of glue rubbing, and the effects of rubbing are different. The color is different, and it has a great relationship with the wax used. The price is moderate. However, the artistry is very difficult, and it usually requires a unique glue wiper to wipe it well. Now there are leathers made of artificial cowhide, with a thickness of more than 2000 microns, and the price is exceptionally high.

Lining and ironing bottom: The material is generally leather, PU, ​​PVC, etc. The leather upper is generally equipped with a leather lining, which is comfortable to wear, has good heat dissipation, and is not easy to produce “Hong Kong feet.” Generally, the lining of PU is much better than that of PVC, but the price is higher!

The sole will be an essential part of the shoe, including PU sole, TPR sole, PVC sole, MD sole, and combination sole. The advantages of PU bottom are lightweight, soft texture, and good hand feeling. Many customers in the Middle East and Europe like PU soles, but the price is high (the price of PU has risen recently, and the cost has increased significantly, but the price of shoes has not risen, which makes many factories embarrassed), and now there is polyurethane injection molding ( After PU INJECTION, due to the large output and lower cost of the machine, it is also trendy. TPR soles are moderate in weight and have a certain degree of flexibility, but the price is lower than PU, and there is no peculiar smell. PVC soles are the cheapest. Generally, It is injected directly into the factory, but the cold glue sole is also PVC material. The texture can be adjusted by pre-molding, which can be hard or soft, but the PVC sole has a little peculiar smell because it is a plastic material. If you mix plastic with good oil, The smell is very weak, but the smell is pungent and uncomfortable if the oil is used back. It depends entirely on the reputation of the factory.

Other parts, such as the midsole, are just the sole and the upper layer. The material is single so I won’t talk about it here. Steel toe is a layer of cardboard measured in millimeters. The quality of steel toe produced in Taiwan is better, and the 1.7mm steel toe is already perfect. It is mainly used in the toe and heel to make the leather shoes look sharp and sharp and play a role in strengthening the shoe’s shape.

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