What Are The Current Advanced Technologies For Injection Molds?
At present, the advanced technologies for injection molds at home and abroad mainly include the following:
1. The hot runner technology system is an important part of the mold production. The working principle is to install the manifold and the hot nozzle in the injection mold. The temperature control should be reasonable, and the runner part should always be in a molten state. The system generally consists of the following Part of the composition:
(1) hot runner plate (MANIFOLD);
(2) Nozzle (NOZZLE);
(3) temperature controller;
(4) Auxiliary parts.
2. Reaction injection molding technology
It is a method in which two or more kinds of chemically reactive liquid plastics (monomers) are simultaneously input into a mixer and mixed at a certain pressure, and the uniformly mixed liquid is quickly injected into a closed mold to make it in-form. The polymerization process in the cavity is solidified to become a plastic article having a certain shape and size. Usually, the forming process is called RIM.
3. Gas-assisted injection molding technology
It injects an accurately metered plastic melt into the cavity, injecting a compressed gas into the melt through a special nozzle, the gas advances in the direction of the least resistance in the melt, pushing the melt to fill the cavity and melt The pressure is maintained. When the pressure of the gas and the injection time are appropriate, the plastic will be pressed against the wall of the cavity by the pressurized gas to form a hollow, complete plastic part, which is discharged into the melt after the plastic melt is cooled and solidified. Gas, open the mold to exit the product.
The key to gas-assisted injection molding technology is how to reasonably grasp the time of injection of molten plastic and the time of gas filling. Gas-assisted injection can be applied to any thermoplastic and part of thermosetting plastics other than particularly soft plastics. The gas-assisted forming cycle can be divided into the following six stages: plastic melt filling stage, switching delay time, gas injection stage, pressure holding stage, gas release stage, and introduction stage.
4. Injection molding technology
It is an injection molding machine that uses two or more injection systems to mold different types or different colors of plastic into the same mold simultaneously or sequentially.
Most of the domestic use is a two-color injection molding machine. When producing plastic products by co-injection molding, the most important process parameters are injection volume, injection speed and mold temperature.