Views: 10 Author: Site Editor Publish Time: 2021-03-12 Origin: Site
High-pressure foaming machine is one of the main equipment in the production line of refrigerators and freezers. Foaming is a very critical process in the manufacturing process of household refrigerators and freezers. The good quality of foaming will directly affect the refrigeration effect of refrigerators and freezers. The strength of the refrigerator. So what should we do if there are cavitations in the foaming process? Let's take a look down together!
1. Controlling the operating temperature of the high-pressure foaming machine is a main problem in solving cavitation. When the temperature is too high, the reaction is violent and it is not easy to control. It is prone to uneven performance of the bubble liquid injected into the larger tank. The bubble liquid injected at the beginning will undergo a chemical reaction and the viscosity will increase rapidly, and then if the bubble liquid injected has not reacted yet. As a result, the foamed liquid injected later cannot push the foamed liquid injected first to the front end of the foaming process of the box, and the phenomenon of partial cavitation of the box appears.
2. The amount of injection should be based on the requirements of the process as the standard. When the injection volume is lower than the process requirement, the foam molding density will be low, the strength will be low, and there will even be the phenomenon of inadequate filling of cavitation. When the injection volume is higher than the process requirements, there will be foam expansion and leakage, and the box body (that is, the door body) will be deformed.
3. Strictly control the ratio and injection volume of the original liquid of the foaming machine, and control the ratio of black material, combined polyether and cyclopentane. When the total injection volume remains the same, if the proportion of black material is too large, cavitation will occur, while if the proportion of white material is too large, soft bubbles will occur. If the proportion of cyclopentane is too large, bubbles will occur. If the ratio is too small, cavitation will occur. The proportion of black and white materials is out of balance, resulting in uneven mixing and shrinkage of foam.
4. Strictly control the temperature of the foaming mold and the ambient temperature of the foaming furnace. The black and white materials should be treated at a constant temperature before foaming, and the foaming temperature should be controlled at about 18-25℃, the preheating temperature of the foaming equipment should be controlled at about 30~50℃, and the temperature of the foaming mold should be controlled at 35 ~45℃, when the temperature of the foaming mold is too low, the fluidity of the foam system is poor, the curing time is long, the reaction is not complete, and the problem of cavitation occurs. When the temperature of the foaming mold is too high, the plastic liner is It will be deformed by heat, and the bubble-liquid system will react violently.