Injection molding release agents are generally used for demolding on injection molds. In some cases, secondary processing is required, so oil-based release agents that affect secondary processing cannot be selected. Instead, dry or super dry release agents should be used. It can be seen that the choice of release agent varies depending on the situation. So, how should injection molding release agents be selected?
The selection of release agent should be determined based on the raw materials used for injection products. One of the most commonly used release agents is zinc stearate, which can be used for all raw materials except polyamide resin. Another type is liquid paraffin (commonly known as white oil), which is commonly used in polyamide resins; There are also silicone oil release agents, which have good release effects but are relatively expensive. Currently, the most widely used and convenient method is to use spray atomized release agents.
The demolding problem encountered in the injection molding production process: sticking phenomenon, poor demolding effect, and solution Adjust the needle position, injection pressure, cooling time, and whether the selection of release agent is appropriate. For large items such as televisions and refrigerators, oil-based or high oil release agents must be used. The phenomenon of "oil droplets" remaining in plastic products affects the solution for secondary processing By using dry and oily release agents to spray evenly on the mold surface 25-30CM away from the mold surface, the problem can be easily solved.
How to choose injection molding release agent? Injection molding release agents must meet the following requirements:
1. Emulsion.Choose appropriate emulsifiers to emulsify silicone oil and prevent carbonization at high temperatures. To maintain the cleanliness of the product and mold cavity surface.
2. Water based release agent.Due to the high temperature of the mold, any solvent based release agent is not suitable. Using water as a dispersing medium, in a high-temperature environment, the water evaporates rapidly, and the effective material for demolding is evenly distributed on the surface of the mold cavity. Uniform film formation, strong adhesion, high temperature resistance, and good demolding performance.
3. Release agents do not corrode castings or mold equipment.The casting product has a clear contour, a smooth and seamless surface, and does not affect the painting process. Volatile substances are smoke-free, non-toxic, do not pollute the environment, and do not harm the health of operators.
The role of injection molding release agents varies in different situations, so when using injection molding release agents, one should choose and purchase according to their own needs and not blindly use them.
