To understand the custom production process of injection molds, one must first recognize the widespread adoption of automated machinery across various industries, including the manufacturing of plastic products. Today, the housings of common household appliances and digital products are typically produced through injection molding using molds and injection molding machines.
- Heating and Pre-plasticizing Driven by the transmission system, the screw continuously transports and compresses the material from the hopper. The material gradually melts under the combined action of the heater outside the barrel and the shear and friction between the screw and the barrel. When the molten plastic reaches the front of the barrel, a certain amount of molten plastic accumulates. Under the pressure of the melt, the screw slowly retracts. The retraction distance is adjusted based on the metering device’s set injection volume, after which the screw stops rotating and retracting.
- Mold Clamping and Locking The mold clamping mechanism closes and locks the mold halves—one on the moving template and the other on the fixed template—providing sufficient clamping force to ensure the mold remains secure during the molding process.
- Injection Unit Moving Forward After the mold is clamped, the injection unit is pushed forward, aligning the injection machine’s nozzle tightly with the mold’s main sprue.
- Injection and Pressure Holding Once the mold is locked and the nozzle is fully aligned with the mold, the injection hydraulic cylinder enters a high-pressure state, pushing the screw forward to inject the molten plastic into the mold cavity with sufficient pressure. As the plastic cools, it shrinks, so maintaining a certain pressure in the cavity is necessary to ensure the density, dimensional accuracy, and mechanical properties of the molded part.
- Pressure Relief
Once the molten plastic at the mold’s gate cools and solidifies, pressure relief can take place. - Retraction of the Injection Unit
After pressure relief, the screw typically rotates and retracts to prepare for the next round of material feeding and pre-plasticizing. It is important to note that in certain cases, such as when using PA materials, the injection unit may retract to prevent drooling during molding. - Mold Opening and Ejection of the Plastic Part
After the plastic part inside the mold cavity cools and solidifies, the mold clamping mechanism opens the mold, and the part is ejected from the mold. At this point, a complete plastic product is produced.
Most plastic parts, after production, typically undergo additional processes such as painting, screen printing, hot stamping, or laser engraving. The final product is then assembled with other components before being delivered to consumers.
DAYIN Plastic Products Co., Ltd. is a high-tech enterprise dedicated to product research, design, manufacturing, and sales services, providing a one-stop solution as a manufacturer. Established in 1989, the company specializes in mold development, injection molding, post-processing, and electronic assembly. In addition to OEM services, we also develop proprietary products for customers to directly label and customize for production. With a 50,000-square-meter manufacturing facility, 30 years of mold development experience, over 50 R&D personnel, and more than 100 injection molding machines, DAYIN offers comprehensive solutions to meet diverse manufacturing needs.