1. Mold preheating: Before pressing, open the mold temperature controller to preheat the mold to remove moisture and other volatiles, which can increase the curing speed, shorten the pressing cycle, improve the uniformity of the cured product, improve the physical and mechanical properties of the product, and improve The fluidity of the molding material.
2. Molding temperature control: In the molding process, the function of the mold tempering furnace mainly includes three processes: mold installation and heating, heating rate control and molding insulation. The temperature setting required for the mold depends on the type of material and the quality of the molded material. The molding temperature is closely related to the type of molding material. The setting of the molding temperature depends on the curing system of the resin paste, the thickness of the product, the production efficiency and the complexity of the product structure.
Mold temperature control must be kept within a reasonable range, because the mold temperature is too high, the material reaction speed is too fast, local solidification, can not fill the mold cavity, there will be shortage of materials, air bubbles; on the contrary, the temperature is too low, the product Insufficient holding time will cause the defect of incomplete curing; if the temperature of the upper and lower molds is not uniform, or the temperature of the large mold is inconsistent, the FRP products will warp and deform, which will affect the dimensional accuracy.
3. In the curing stage, the temperature stability of the mold temperature machine can completely cure the product and eliminate internal stress. The European machinery glass fiber reinforced plastic SMC special mold temperature machine uses heat transfer oil as the heat transfer medium, the temperature can reach 300 ℃, and the temperature control accuracy can be controlled at 0.5 ℃.
4. Cooling process
Only when the mold temperature drops below 60°C during slow molding, can the demolding operation be carried out. There are mold temperature controllers with natural cooling and forced cooling. The rapid pressing process cannot be used for cooling operations. After the heat preservation, the product can be taken out of the mold at the end of the molding temperature, and then necessary auxiliary processing is performed to obtain the product.
Generally speaking, the temperature control process of SMC glass fiber reinforced plastic mold mainly includes two aspects, one is mold preheating, and the other is mold temperature control during mold forming. The temperature control must ensure that the crosslinking reaction proceeds smoothly after the resin curing system is started, and Finish curing.
Post time: Mar-10-2021