PVC is a polar amorphous polymer with a strong interaction between molecules. It is a hard and brittle material with low impact strength. After the impact modifier is added, the elastomer particles of the impact modifier can reduce the total craze-inducing stress, and use the deformation and shear band of the particle itself to prevent the silver grain from expanding and growing, and absorb the impact energy in the body material. In order to achieve the purpose of impact resistance.
PVC soles are generally divided into two types. One is made of soft PVC, and a suitable amount of foaming agent is added to form a sheet, which is formed into a foamed plastic to form a foamed PVC sole; the other is made by using an injection molding machine with various molds. PVC sole.
PVC soles have good physical and chemical properties. From an intuitive point of view, it can be said to be a plastic material, characterized by lightness, high gloss, but lack of texture.
- PVC foam slippers
The foam sole is made of PVC as a basic raw material, and is added with a plasticizer, a foaming agent and other auxiliary agents, and is kneaded, masticated, pulled, punched, and finally obtained by a compression foaming method. The non-foaming shoe climbing is kneaded, granulated, and then made by injection molding, and no foaming agent is added to the shoe climbing material. PVC foam slippers are soft and comfortable to wear and are easy to make a variety of colors. It is the largest type of slippers. The disadvantages are complicated procedures, strict operation procedures, and low production efficiency.
The sole of PVC foaming slippers is produced by a molding foaming process, and the main operations are as follows.
- Ingredient kneading The raw material PVC resin is poured into a kneading machine, and the various additives are added to perform heating and kneading. The heating steam pressure is about 0.29 MPa, and the contract is discharged after 45 to 60 minutes.
- Molding and pulling sheet The kneaded mixture is sent to a two-roller plastic mixer for plasticating and pulling, and the mastication temperature is controlled at about 130 °C.
- The 3 die-pressing blanks are obtained by punching the pieces after the mastication according to the sample plate (generally rectangular), and the pieces of the various colors can be matched according to the color requirements of the soles, and then the pieces are weighed according to the cavity capacity. Weighing should be more accurate to prevent flashing or lack of material. Then, the mold containing the sheet material is sent to a hot press for heating plasticizing, foaming, foaming, cooling and setting, and then demolding to remove the plasticized blank. The mold pressing conditions are as follows: molding plasticizing temperature is 160~165 °C. The heating steam pressure is 0.686~0.784MPa, the molding plasticizing pressure is 4. 9MPa, the molding time is 10~20min, the cooling setting temperature is 50°C, and the cooling setting is 20min.
- The purpose of the heat treatment heat treatment is to further heat and foam the billet under normal pressure to obtain a foamed sole sheet. The operation is to send the bad material into a steam-heated drying room, and the temperature is controlled at 100~130 ° C for about 10-15 minutes. After foaming, the foamed sheet of the obtained foaming slippers bottom is sent out of the drying room and then sent to the warehouse for one week before being sent to the punching sheet.
- Blanking and assembly The foamed sheet material is punched out into the slippers according to the specifications of the slippers, and then the eyes are punched and assembled with the slippers to obtain the finished slippers.
The main equipment of PVC foaming slide includes kneading machine, double-roller refining machine, extruder, injection molding machine, and punching machine, all of which are general-purpose equipment and have no special requirements. The hot press should use a multi-layer laminating machine, generally using a two-layer hydraulic press of 100~200t class.
PVC soles are generally suitable for fashion shoes, because of its light and thin characteristics, the shoes have a strong three-dimensional view, which can highlight the smooth lines unique to fashion shoes, and thus appear to be superior.