The reaction-injection molding process (RIM)

• Storage: The two liquid raw materials used in the RIM process are stored in two large tanks at a certain temperature, and at an approximate pressure of 0.2 ~ 0.3 MPa. These liquids circulate between heat exchangers and mix-heads in a speedy, continuous loop. As in the case of polyurethane, the average storage temperature is 20 ~ 40 ° C, and the temperature tolerance is ± 1 ° C.
• Measurement: The dosing pump is responsible for the measurement and tolerance requirements are at least ± 1.5%.
• Hybrid: In the RIM process, the quality of the product depends largely on the mixture made in the mix-head. The normal pressure is approximately 10 MPa in order to obtain the best results.
• Deposition in the mold: The characteristic of RIM process is that the material flow rate is very high, so the viscosity cannot be very high. The viscosity of the polyurethane mixture when falling into the mold is approximately 0.1 Pa and frequency control flow is 600 g / s.
• Curing: The mixture of the two polyurethane components has a very high reactivity after being injected into the mold, so a complete cure takes only ten more minutes. The problem is that the conductivity of the plastic is not very high, so the curing process is from the inside out.
• Demolding: Demolding means to remove the finished part from the mold.
• Post-Processing: The treatment or coating requested by the customer is applied to the part.