RESIN TRANSFER MOLDING
Resin transfer molding (RTM) is a low pressure closed
molding process for moderate volume production
quantities, filling the gap between the slow, contact
molding processes and the faster, compression molding
process, which requires higher tooling costs. Continuous
strand mats and woven reinforcement is laid up dry in the
bottom mold half. Preformed glass reinforcements are
often used for complex mold shapes. The mold is closed
and clamped, and a low viscosity, catalyzed resin is
pumped in, displacing the air through strategically
located vents. Metered mixing equipment is used to
control resin/catalyst ratios that are mixed through a
motionless/static mixer and injected into the mold port.
Common matrix resins include polyester, vinyl ester,
epoxy, and phenolics. Advantages over contact molding
methods are a uniform thickness, two finished sides and
low emissions. For optimum surface finish, a gel coat
would be applied to the mold surface prior to molding.
High quality parts produced by this method include
automotive body parts, bathtubs, and containers.
Photos from recent seminars on the subject of resin
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CT Processes | Participants | Links
Web Author: Terry Price (tprice@cerritos.edu)
Disclaimer
Last update: 11/14/01 |
