To Control the Main Process
The production process of EPS molded products is as follows:
Raw material → pre-expansion → ripening → forming → cutting → drying → finishing → leaving the factory
In the production process, the pre-expansion process is its key process. In the pre-expansion process, you should pay attention to:
1. According to the requirements of different products, choose different pre-expansion capacity, usually expressed by magnification. Magnification refers to the reciprocal of the weight value of the foam particles per unit volume and is a dimensionless unit. Since the specific gravity of water is "1", it can also be expressed by the following formula: Magnificati per unit volume of water / weight of foamed plastic particles per unit. The EPS foaming rate is too low, which increases the unit consumption of molded articles and increases production costs. If it is too high, it will cause the pre-expanded particles to collapse and affect the quality of the forming port. Therefore, each batch of materials needs advanced small batch trials. In the trial pre-issue, according to the quality of the eps raw materials, the trial pre-expansion ratio is reasonably selected. For eps raw materials that have never been used, it should be started from a low rate, and the pre-expansion and molding conditions will gradually increase until the desired effect. In particular, it should be noted that when a foaming product processing manufacturer and a customer sign a processing contract, the buffered foam products are generally priced based on the weight of the sample, while the raw materials, that is, the plates are priced by volume, so the foaming product processing manufacturer wants to innovate. Benefits can be achieved by appropriately increasing the pre-expansion rate and reducing product consumption.
2. The ordinary material and the self-extinguishing material should be separated during the production process, and the material should be blended when pre-expansion or feeding, so as to avoid leaving fire. 3. Prevent the vapor pressure from becoming too small and small, keep it stable, the time of the raw material staying in the machine is suitable, the feeding and discharging speed are evenly distributed, and the particle size specifications are suitable. The ripening process has sufficient ripening time, generally about 8 to 48 hours.