At present, most of the appearance parts of household appliances are obtained by injection molding. In the injection molding process, defects such as weld marks, gas marks, and deformation are prone to occur; high-gloss non-marking molds can solve the above-mentioned defects. Let’s take a look at the ten elements of high-gloss seamless injection mold design.
The principle of high-gloss seamless injection molding
1. Higher temperature Mold molding has higher temperature requirements (usually around 80°C-130°C). After the injection is transferred to the holding pressure, cooling water is used to reduce the mold temperature to 60-70°C. Pressure-holding molding at a higher mold temperature is beneficial to eliminate defects such as weld lines, flow marks, and product internal stress. Therefore, the mold needs to be heated when it is working. In order to prevent heat loss, a heat shield is usually added to the side of the fixed mold.
2. The surface of the cavity is extremely bright (usually mirror level 2 or higher)
The products produced by the high-gloss mold can be directly used for installation (assembly) without any surface treatment. Therefore, it has high requirements for mold steel and plastic materials.
3. There are more hot nozzles in the hot runner system
Each thermal nozzle must be equipped with a sealing needle and an independent air passage, which is individually controlled by solenoid valves and time relays to realize time-sharing glue feeding, so as to achieve the purpose of controlling or even eliminating weld marks. The control method is complicated.
4. Heating method
Mold heating methods usually have steam (hot water) heating and electric heating rod (tube) heating. The steam (hot water) heating method is to input steam (hot water) to the mold during the injection molding process through a specific temperature control machine, so that the mold is quickly heated; after the injection is completed, the mold is cooled with cold water to cool the mold quickly. The electric heating method is the same as the water heating temperature controller in principle, that is, the heat source is different. Electric heating is a secondary energy source, and water heating is a tertiary energy source. According to the principle, electric heating energy consumption is low, and the utilization rate is high. Good energy-saving benefits. It is easy to use, so it is said that if it is a flat (noodle) product, it is still economical to use electric heating.
Post time: Sep-22-2021