The die-casting release agent is a functional substance between the mold and the finished product. It is a type of processing aid that prevents the metal molded product from sticking to the mold and plays a role of easy detachment. Due to the rapid development of die-casting technology, the amount of release agent has also been greatly increased.

The choice of release agent The commonly used release agents are inorganic, organic and polymer. Inorganic mold release agents, such as talc powder, mica powder, pottery clay, white clay, etc. as the main components of the compound, are mainly used as a release agent for the film and semi-finished products in rubber processing. Organic mold release agents include fatty acid soaps (potassium soap, sodium soap, ammonium soap, zinc soap, etc.), fatty acids, paraffin wax, glycerin, petrolatum and the like. The third type of release agent is a high polymer, including silicone oil, polyethylene glycol, low molecular weight polyethylene, etc., and their release agent efficiency and thermal stability are much better than organic release agents. Mold release agents are usually divided into powder, semi-solid and liquid. The powder and semi-solid can be applied to the surface of the mold with a brush or hand like wax grease. The liquid can be sprayed or brushed on the surface of the mold to form an isolation film. The liquid release agent is preferably sprayed.

In industrially developed countries, mold release agents filled with metal spray cans are mostly used. Due to the good sealing performance of the metal spray can, it can prevent the release agent from being oxidized or mixed with impurities, and can ensure the purity of the release agent when it leaves the factory. Large-scale injection molding equipment is installed indoors, with small changes in ambient temperature, and has no effect on the use of spray release agents. However, the temperature of the mold for compression molding should be considered, and a mold release agent with good thermal stability should be selected. Generally, the thermal decomposition temperature of the mold release agent is required to be higher than the mold temperature for molding. Otherwise, charring will occur. High-end products and secondary processing (such as painting and printing) should choose a release agent suitable for secondary processing. In order to prevent environmental pollution, it is necessary to use a mold release agent that is not easy to burn, has low odor and toxicity. In the selection of release agents, economy is an important factor that cannot be ignored. Poor quality release agents will cause cracks and wrinkles on the surface of the product, affect the appearance of the product and the service life of the mold, and cause environmental pollution. Choose high-quality spray release agent, the price is higher, but the comprehensive economic benefits are high.

To sum up, the key points for selecting mold release agents are: ①Excellent mold release, and the surface tension of spray mold release agents should be between 17 and 23 N/m. ②It has heat resistance and will not be carbonized and decomposed when heated. ③Stable chemical performance, no chemical reaction with molded products. ④Does not affect the secondary processing performance of die casting. ⑤It does not corrode the mold, does not pollute the product, and has low odor and toxicity. ⑥Smooth and beautiful appearance; ⑦Easy coating and high production efficiency.