Plastic injection molding refers to a method in which completely melted plastic materials are mixed with a screw at a certain temperature, injected into the mold cavity with high pressure, and then cooled and solidified to obtain a molded product. This process began in the 1920s and has a development history of nearly a hundred years. It is a widely used and mature industrial manufacturing technology.
Injection molding is a method of producing shapes. Products generally use rubber injection molding and plastic injection molding. Injection molding can also be divided into injection molding molding method and die casting method.
Rubber injection molding is a production method that injects rubber material directly from the barrel into the model for vulcanization. The advantage of rubber injection molding is that although it is an intermittent operation, the molding cycle is short and the production efficiency is high. The blank material preparation process is eliminated, the labor intensity is low, and the product Excellent quality.
Plastic injection molding is a method of Surya products. The molten plastic is injected into the plastic product mold using pressure, and then cooled and molded to obtain the various plastic parts you want. There are plastic injection molding machines that specialize in injection molding. Currently, the most commonly used plastic It is polyethylene, polypropylene, ABS, PA, polystyrene, etc.
In injection molding, the resulting shape is often the final product. No other processing is required before installation or use as a final product. Many details, such as raised parts, ribs, and threads, can be produced in one step of the injection molding model. .
Here are some pictures to show you the production process of plastic baskets. This is what we often call the injection molding process.
Some friends are curious, how to control the temperature of injection molding? Hydraulic injection molding machines generally use hydraulic oil for pressure transmission. Appropriate oil temperature can greatly extend the service life of the machine and improve its stability. The first is because the oil seal will age; the second reason is that the expansion coefficient of the oil seal is far different from the expansion coefficient of the cylinder, which is the main cause of oil leakage in the hydraulic machine.
So now a small number of injection molding machines use rare earth metal oil seals. The sealing rings of the injection molding machine cylinder are mostly U-shaped rings made of PU material. Due to the characteristics of polyurethane plastic, its normal operating temperature is about -30 to 80°C. If the oil temperature exceeds 55°C, due to the heat conduction of the oil cylinder, the sealing ring’s own temperature will exceed 55°C when it is stationary, and friction heat will be generated during movement. When the sealing ring rubs against the contact surface of the workpiece, the surface temperature will exceed 100°C, which will greatly shorten the service life of the sealing ring under long-term operation, and the material on the working surface of the sealing ring will accelerate aging and deformation.
The following is a list of temperatures required in the injection molding process of some commonly used plastics:
There are also risks in injection molding operations. Jinsubao has summarized these precautions, so be sure to keep them in mind!
1. The heating system and automatic temperature control system are not equipped with interlock devices and machine overheat protection functions. Once the temperature is too high, a fire accident may occur.
2. The exposed dangerous parts and rotating parts of the equipment are not equipped with safety protection devices, which may cause mechanical injury accidents.
3. The injection molding machine is not equipped with protective grounding or zero connection, poor grounding; electrical short circuit, open circuit, bare wire, etc. , may cause electric shock accident.
4. The injection molding machine is not equipped with an emergency stop device, the location is not obvious or the emergency stop device fails. In the event of an emergency, the equipment cannot stop running immediately, which may cause mechanical injury to the operator.
5. During the operation of the equipment, personnel will violate the operating procedures and extend their hands into the operating area, causing cuts, squeezing, burns or crushing injuries.
Post time: 05-11-2024
