Reinforced Reaction Injection Moldings

F. R. Jones, Reinforced Reaction Injection Molding, Handbook of Polymer Fibre Composites, (F. R. James, ed.). Polymer Science and Technology Science, New York (1994). 

Reimer-Tiemann reaction, 6 236 of salicylic acid, 22 5 Reinforced composites flax fiber in, 22 594 silylating agents and, 22 701-703 Reinforced plastics, 26 750-751 asbestos applications, 3 311 Reinforced polyester composites, 20 114 Reinforced reaction injection molding (RRIM), 25 456 Reinforcement... 

A3 + C3) Chopped fiber Reinforced reaction Injection molding, RRIM No Yes... 

The formulations given below (in parts by weight) are three examples of typical formulations from the many available, which have been designed to meet specific requirements. Noteworthy points reading the formulations are explained. An example of formulation for reaction injection molding (RIM) and reinforced reaction injection molding (RRIM) is also given,... 

RH relative humidity RRIM reinforced reaction injection molding... 

Polyurethanes (PU or PUR) and polyureas are classified as TS resins, but their chemistry is so flexible that they can be formulated different ways. There are moldable solid and expanded TSs, with (RPUR) or without reinforcement, flexible and rigid foams, elastomers and thermoplastic molding compounds. As RPs they are important in reinforced reaction injection molding (RRIM) (Chapter 5) and are also available as reinforced thermoplastic molding compounds. A variant on the process employs a structural preform of the reinforcement that is placed in the mold cavity and is called structural reaction injection molding (SRIM). 

There is no single method for treating polymethane (PUR) waste, due to the different quantities, qualities, mixes, and cleanliness. It is estimated that some 125,000 t of RIM polyurethane is used worldwide, 85% in automotive parts, mainly in bumper fascias. Current technologies for physical recycling of PURs are mainly directed towards flexible and rigid foams, but systems have also been developed for recycling reinforced reaction injection molded (RRIM) PURs, on the... 

Details on reinforced reaction injection molding (RRIM) using TS polyurethane (PUR). Two-component PUR mixtures, in which a polyol and isocyanate are brought together and a fast reaction takes place to produce a solid compound with useful properties lend themselves well to molding with reinforcement. This can be a flat or preformed mat placed in the mold, or a chopped reinforcement introduced into the stream of components in the mixing head. 

For RPs, electroformed molds are mainly useful for autoclave molding and for closed matched die molding (cold press, low-pressure hot press, resin injection, resin transfer, low-pressure phenolic molding, and resin casting) as well as for reinforced reaction injection molding (RKIM). Prototyping can also use this technique for mold-making. 

Ford Motor Co. of Dearborn, Mich., uses SMC for the bed of its Explorer Sport Trac. General Motors Corp. uses mostly reinforced reaction injection molding (RIM/Chapter 5) for the beds of its Chevrolet Avalanche and Escalade EXT trucks. 

In painted SMC in particular (as weh as in RIM or RRIM - reinforced reaction injection molding - of polyurethane), mold release agents (zinc or calcium stearates) are used that exudate at the molding surface during curing/crosslinking and make for efficient demolding. 

Passenger Car Door Sills Made by the Polyurethane RRIM Technique (Reinforced Reaction Injection Molding) Compared to Injection Molded PC/ABS Blend... 

Injection molding Hand lay-up Spray-up Compression molding Preform molding Filament winding Pultrusion Resin transfer molding Reinforced reaction injection molding ... 

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