1. Rubber release agent: refers to a type of substance used to prevent rubber products from adhering to the surface of molds and to ensure smooth demolding without tearing. Spray or apply it onto the surface of the mold cavity during use to form an effective isolation layer. The main requirements for release agents are: they have certain thermal stability and chemical inertness, and do not corrode the surface of the mold cavity; Residual decomposition products under the surface of the mold cavity; Does not affect the color of the product, but can give it a good appearance and is non-toxic; Easy to configure and convenient to use.
2. Fluorine based release agent: Fluorine based release agents inherit the characteristics of fluorine-containing materials and can significantly reduce the surface energy of solids, making them difficult to wet and non stick, and difficult to dissolve with other substances, effectively solving the bonding problem between finished products and molds. When formulated as release agents, the amount of fluorine-containing compounds is extremely small. Suitable for thermosetting resins, thermoplastic resins, and various rubber parts, the surface of molded products is smooth and the secondary processing performance is excellent, especially suitable for demolding of fine electronic components.
3. Silicon based release agent: Organosilicon release agent is prepared from organosiloxane as raw material. Its advantages include good heat resistance, moderate surface tension, easy formation of uniform isolation film, and long release life. The disadvantage is that there is a layer of oily surface on the surface of the product after demolding, and the surface of the secondary processing label must be cleaned. Commonly used ones include silicone oil, silicone rubber, emulsified silicone oil, and silicone grease. Organic silicone release agent is currently the mainstream product in the mid-range market of rubber and plastic release agents, widely used in the processing of resins such as polyurethane, rubber, etc.
4. Wax (oil) series release agents are characterized by low price, good adhesion performance, but the disadvantage is mold pollution. The main varieties are:
① Industrial Vaseline, directly used as a mold release agent;
② Paraffin wax, directly used as a release agent;
③ Sulfonated vegetable oil, directly used as a mold release agent;
④ Printing and dyeing oil (Türkiye red oil, Taikoo oil), lotion made by adding 0.9~2 parts of printing and dyeing oil to 100 parts of boiling water, has better demoulding effect than soapy water;
⑤ Polyethylene glycol (with a relative molecular weight of 200~1500) is directly used for demolding rubber products.
5. Surfactant based release agents are characterized by good isolation performance, but they can contaminate molds. There are mainly the following categories:
① Soap water, mixed with soap to form a certain concentration of aqueous solution, can be used as a lubricant for molds or as a core remover for rubber hoses;
② Sodium oleate, mix 22 parts of oleic acid with 100 parts of water, heat to near boiling, then slowly add 3 parts of caustic soda and stir until saponification, control the pH value to 7-9, dilute with 1:1 water when used, and add 2 parts of glycerol to 200 parts of the above solution for vulcanization and demolding of outer tires;
③ Glycerol can be directly used as a release agent or water-based lubricant.
④ Fatty acid aluminum solution, prepared by dissolving fatty aluminum in dichloroethane to form a 1% solution, suitable for polyurethane products, coated once, can be reused multiple times, and has good demolding effect;
⑤ Zinc stearate is a release agent for transparent plastic products.
6. Internal release agent
Zinc stearate, ammonium stearate, paraffin wax, etc. are suitable as internal release agents;
