Fibre reinforcement, RRIM

The reinforced reaction injection moulding (RRIM) process is a development of RIM in which reinforcing fillers such as glass fibres are incorporated into the polymer. One advantage of such a system is to reduce the coefficient of thermal expansion, and with a 40-50% glass fibre content the coefficient is brought into line with those of metals. 

RRIM - reinforced reaction injection moulding - the resin is reinforced with short fibres... 

Typical systems are two-part polyurethane systems that may produce rigid, rubbery, foamed or filled products. Typical fillers include chopped fibres and mineral fillers. Composite systems may also be produced by having pre-placed reinforcements in the mould, in which case the technique is known as reinforced reactive injection moulding (RRIM). 

RRIM polyurethanes are an extension to Reaction Injection Moulding (RIM) which is a relatively recent, but now established, plastics processing technique. Simplified, RRIM is the inclusion of a reinforcement - short glass fibres - into one of the components used in the RIM process. However, the inclusion of glass reinforcement into one of the reactive components, usually the polyol, has meant that certain processing equipment modifications were necessary in order to handle the... 

If short fibres or fillers are introduced into the mould, the process is called reinforced reaction injection moulding (RRIM). 

High performance composites for this industry must have continuous reinforcement. This contrasts with the chopped fibres used in reinforced RIM (known as RRIM) [1], where short fibres are injected into the moulding via a slurry in one (or both) of the reactant streams. The use of a continuous reinforcement necessitates the placement of the reinforcing package (preform) in the mould prior to dispensing the epoxy resin system. This... 

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