Mold-cavity coating

Since plastics (not containing metallic additives) are not subjected to electrolytic corrosion, they are widely used where this property is required alone as a product or as coatings and linings for material subjected to corrosion such as in chemical and water filtration plants, mold/die, etc. Plastics are used as protective coatings on products such as steel rod, concrete steel reinforcement, mold cavity coating, plasticator screw coating, etc. 

Various types of surface finishes are available for plastics and RP products, such as smooth, textured, molded-in color, and inmold coating. A textured product surface can be obtained through either a textured mold cavity or a postmold paint process. The former method is the most commonly used. A... 

Centrifugal force is used to introduce molten metal into a mold cavity that is spinning around its axis. Cast iron pipe is produced in centrifugal molds, and copper-base alloy bearings are also commonly produced this way. Permanent metal molds are usually coated or lined to extend operating life. 

Different forms of glass fiber-TS plastics are used with or without special surface coatings such as gel coatings. Materials are compounded with controlled pot life so that they start their cure reaction after being placed in the mold cavity. For room temperature cure, cure occurs by an exothermic chemical reaction that heats the RP. Pressures are moderate at about 140 to 350 kPa (20 to 50 psi). Molds can be made of inexpensive metal, plaster, RP, wood, etc. 

Tool coatings/platings are typically used to enhance tool performance in one or more of the following areas wear resistance, corrosion resistance, improved tool release, resizes components, and/or their combination. No single treatment is ideal for solving all these problems. Treatments are used that resist the corrosion damage inflicted by chemicals such as hydrochloric acid when processing PVC, formic acid or formaldehyde with acetals, and oxidation caused by interaction between tools and moisture in the plant atmosphere. Release problems require treatments that decrease friction and increase lubricity in mold cavities.3... 

A mold-release agent is a lubricant, often wax, silicon or fluorocarbon fluid, used to coat a mold cavity to prevent the molded part from sticking to it, and thus to facilitate its removal from the mold. Mold-release agents are often packaged in aerosol cans for convenience in application (1). 

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