Do you know what is Reaction Injection Molding (RIM)?

Reaction Injection Molding (RIM)

Reaction injection molding process is a commonly used processing molding process in industry. It refers to mixing two or more liquid raw materials in a certain proportion under pressure through a high-pressure machine, and immediately injecting them into a closed mold to react rapidly to complete the chain growth, cross-linking and curing of the polymer. Forming process. The process is unique in that it uses two liquid components (isocyanate and polyol) to produce polyurethane, rather than the pellet form of most thermoplastics. The two materials are conveyed under high pressure (approximately 150 bar) through the supply line to the metering device and then to the mixing head device. The liquid is then injected into the closed mold, where it undergoes an exothermic chemical reaction and forms a polyurethane polymer. Injection and cycle times will vary (between 1 and 15 minutes) depending on part size and polyurethane system used. Common molds for Rapid Systems can be filled in one second or less and ready to demould in 30-60 seconds.

Depending on how a polyurethane system is formulated, parts molded with it can be foam or solid, and they can range from flexible to extremely rigid. Part densities can also vary widely, with specific gravity ranging from 0.2 to 1.6 (including filler). We offer a wide range of polyurethane technologies for RIM technology for different applications:

Flexible polyurethane foam technology – e.g. wrist rests and mouse pads
Rigid polyurethane foam technology – e.g. thermal insulation components
Integral skin polyurethane foam technology – e.g. armrests and headrests

History of Reaction Injection Molding (RIM)

At the heart of the polyurethane RIM process is the chemical reaction between two liquid components held in separate temperature-controlled feed tanks equipped with agitators. From these tanks, the isocyanate and polyol are conveyed through supply lines to a metering unit that precisely meters the two components under high pressure into a mixhead unit. When the liquid begins to pour into the mold, a valve in the mixing head opens. The liquid reactants enter a chamber in the mixing head at a pressure of 100 to 200 bar and are thoroughly mixed by high-speed impingement. The liquid then flows from the mixing chamber into the mold at approximately atmospheric pressure. Inside the mold, the liquid undergoes an exothermic chemical reaction that forms the polyurethane polymer in the mold.

Injection and cycle times will vary depending on part size and polyurethane system used. Common molds for elastic parts can be filled in a second or less and ready to demould in 30-60 seconds. Special extended gel time polyurethane RIM systems allow processors enough time to fill very large molds with equipment originally designed for smaller molds.

HLLFOAM–Let us identify the right foam for your product

Polyurethane RIM process, according to the formula used, produces different polyurethane products. So far, it can be divided into the following categories: rigid foam, integral skin foam, semi-rigid foam. These products are used in different fields. It is worth mentioning that we can manufacture products that meet the requirements of different customers by changing the formula or changing the processing environment according to the different needs of different customers. And our customers don’t have to bear any experimental costs.
Our real strength lies in formulating these individual components into polyurethane systems that contain only the right isocyanate and polyol – along with any fillers, internal mold release agents or other ingredients – to produce the processing and physical properties you need. From structural foam RIM systems to solid polyurethane systems to advanced RIM composite systems, we have a broad range of polyurethane technologies to meet virtually any need.

If you need technology that we don’t already have, our polyurethane experts and technical service representatives can work with you to develop the right formulation for your application. So whether you choose one of our standard polyurethane RIM technologies or require a custom formulated system, you can leave the polyurethane chemistry to us while you focus on manufacturing your product.

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1人评论了“Do you know what is Reaction Injection Molding (RIM)?”

  1. Dear sirs
    We could buy chemicals for mixing of polyol and isocyanate makes Foam for heat & sound isolation layer in automotive shell in the assembling process.
    Quote prices and type of chemcals
    Highly appreciated your attention
    Hoang Hai
    Director of RAN
    company in Viet nam
    Whatsapp 0942868979



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