Foam plastic extrusion molding process and equipment
DATE：2021/9/23 8:41:18 / READ： / SOURCE：This station
Foam plastic extrusion molding process and equipment
Extrusion molding is a continuous production method, so it has a high level of production to achieve automation. High-speed and high-efficiency foam plastic extrusion molding products do not apply to the main market, and the price is also dominant, becoming the main side of foam molding processing, general shaped materials, plates, pipes, diaphragms, electrical insulation layers and other foaming products Extrusion foam molding method can be used.
The basic principle of extrusion foaming molding is similar to ordinary extrusion molding. The problem is to control the appropriate foam. During the extrusion process, plasticization, mixing, decomposition of foaming agent (chemical foaming method) or foaming agent method (physical foaming method), or emotional gas are completed in each extrusion barrel such as plastic and foaming agent. Pressure injection (mechanical foaming method). Regardless of the foaming method, the common process control element is that sufficient extruder head pressure must be established to foam the foam material in advance near the extrusion die. Once the foaming material enters the die, it will be shaped and form a skin with different requirements. The formed foam products are divided into cooling and shaping to complete the cooling and final shaping of the products. Since the thermal insulation performance of the foam is better than that of the base material, the cooling and shaping section of the foamed product is usually longer than that of the ordinary extruder. The cooled and shaped foamed products are then passed through a traction device, a cutting device and a collection device, and then packaged after being measured. The foaming methods commonly used by people are divided into two categories: chemical foaming and physical foaming. The mechanical method can also be classified as a physical foam method. According to the processing technology, it can be divided into two categories: free foaming and foamable. The application status of the general foam plastic extrusion molding technology. You can summarize the list as shown in Table 5-1 (see 143).
2. Extrusion foaming method
As mentioned earlier, in the extrusion molding of foam, there are two industrialized methods: chemical foaming and physical foaming. In theory, both methods are applicable. At present, the most used is chemical foaming, while physical foaming is used in low-density polystyrene foam packaging materials. However, with the development of new foaming technology and Some chemical foaming agents are banned, and the application of physical foaming hair is rapidly expanding.
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