The variety of silicone mold release agents is complex, and the nature and use are different. How to choose the mold release agent to get the best effect? In general, the raw materials, structure and shape of the mold, the type of finished product to be demolded, the application temperature, the post-processability (printability, adhesion), and the diluent are all necessary conditions for consideration. First of all, the temperature of the metal mold is the primary source of the mold release agent. From the perspective of safety (fire and poisoning), the hot mold cannot be used in solution type, but emulsion type, silicone paste or silicone oil mold release agent should be used. Silicone oil has no expansion and contraction effect on various rubbers and plastics, so it is widely used as a mold release agent for them, but silicone oils are more or less migrating to the appearance of the finished product, which affects their post-processing properties. For example, in the case of molding an epoxy resin, a urethane resin, and a urethane rubber, it is preferable to use a curing mold release agent or a curing mold release agent. For molds that require bonding, finishing, and embossing, mold release agents that cannot be made with dimethyl silicone oil. If a long-chain alkyl silane is used as a mold release agent, the side can eliminate this disadvantage. Any diluent, including organic solvents, propellants, and water, must not remain on the mold. Failure to do so will result in a decline in quality. If the thinner is not properly selected, the silicone oil on the outer surface of the mold will be unevenly distributed, and then the finished product will have problems such as stress cracking and accelerated aging. All of the above are described as the use of the outer mold release agent. In recent years, the use of the mold release agent as an inner mold has been carried out very quickly. This method is to directly participate in the thermoplastic resin in the thermoplastic resin or to prepare a thermoplastic resin pellet containing a high concentration of silicone oil beforehand, and then mix it into the mother guess. For example, in a small amount of silicone oil or silicone oil pellets in polystyrene, acrylonitrile butadiene styrene (aBS), polyolefin, nylon, polyoxymethylene and polyvinyl chloride, the fluidity can be improved in extrusion molding. And the amount of resin discharged. In the injection molding, the recovery time of the screw can be shortened, the fluidity of the resin can be improved, the friction coefficient of the finished product surface can be lowered, and the wear resistance, lubricity, gloss and hydrophobicity of the finished product can be improved. When using dimethyl silicone oil, the viscosity is higher; when participating in methyl phenyl silicone oil, the refractive index can be adjusted to obtain a transparent finished product; when participating in polyether silicone oil, antistatic property can be imparted, so that the finished film product has Anti-adhesiveness; when participating in long-chain alkyl silicone oil, the finished product has post-processability such as printing, finishing and embossing. The introduction of a polyfunctional active MQ silicone resin, a hydroxyl group-containing silicone oil, and magnesium stearate into the thermoplastic resin can also improve the flame retardancy of the finished product. The use of silicone mold release agents in shell molds (casting) and machining has excellent thermal stability and differentiation at high temperatures, so it is widely used in the production of shell molds and forging various metal parts. When making the shell mold, the emulsion type or solution mold release agent is often used, and the mold release agent can be sprayed on the shell mold made of sand and phenolic resin and heated to 250 ° C, and then placed in the heating furnace. It can be processed for several minutes; the mold release agent can also be sprayed on the wood mold and used to make the shell mold. Since the mold release agent is used, it is very easy to release the mold from the mold and the metal mold, and the obtained shell mold can be processed without any additional processing, so that a fine casting can be obtained. Also in the fine forging of low melting point metals such as zinc, lead and alloys thereof, the high temperature resistant silicone oil mold release agent can play an outstanding role, and the concentration of the mold release agent used is 1% to 5% (mass fraction). Fortunately, it is possible to achieve low cost and good intentions. For new molds that are used for the first time, they must be treated with high temperature or solvent, lye or sanded to remove organic matter and oxides attached to the outer surface of the shell mold. Then use a higher concentration of silicone oil emulsion or silicon paste solution to be put into operation. Tempered Smart Glass,Patterned Glass,Tempered Glass Smart Glass,Electric Film Smart Glass SHANDONG TOP LEADER GLASS CO.,LTD , https://www.topleaderglass.com
The use of silicone mold release agents in plastic molding processes has been used in the molding, casting and encapsulation of plastics, rubbers, polymers, metals, glass, molds and foods. The most important application target of silicone mold release agent during plastic molding. Such as in polyurethane, polystyrene, polyvinyl chloride, melamine, acrylic resin, epoxy resin and polyester, such as compression molding, transfer molding, injection molding, casting molding, lamination molding and other technologies. In the meantime, the molding release of polyurethane foam occupies the majority, generally using a solution of 0.5% ~ 2.0% concentration or emulsion mold release agent, spraying it on the cleaning mold, and drying at the molding processing temperature After 30 minutes of drying, excellent release properties can be achieved.