Vacuum-Assisted Resin Transfer Molding (VARTM)

Structural rear step assembly for low-floor bus

RMC’s variation on Closed Cavity Bag Molding (CCBM)

is typified by a rigid cavity mold with disposable bagging materials or a semi-permanent silicone bag as counter-mold. The cavity mold is usually glass-reinforced, low-profile, polyester resin, balsa reinforced with a steel edge, steel frame, and a perimeter vaccuum flange. The process is used for infusing very large parts, at a rate of 4 parts per mold per shift. Molds are inexpensive and have a useable life ranging to 1000 parts, depending on geometry.

Patented Lightweight 3-D Structural Shear Plates for Commercial Vehicles

RMC is the leader in large, 3-dimensional, structural shear panels for the transportation, utility, and infrastructure industries. Our unitized sandwich panels provide a level of unmatched flexibility in high-strength component sourcing and design, backed by solid engineering and testing. OEM applications include molded structural floor, roof, and side wall assemblies for leading transit equipment manufacturers. Benefits range from parts consolidation, reduced assembly labor, to weight reduction, with no leaks, and no rot. Aftermarket replacement kits are an ideal solution for rotting plywood floors & cracking roof membrances, providing a cost-effective means of extending the service life of a transit vehicle or an entire fleet.

Structural floor for medium duty truck cab weighs just 86 lbs(39kg)

You can select from a wide range of core materials to optimize performance, eliminate weight, and control costs:

  • High density PVC, SAN, solid and honeycomb PETG, and polyurethane foam cores can be assembled to create complex 3-dimensional shapes such as bus floors complete with integrated wheel housings, step wells, and fuel tank compartments
  • Optional end-grain balsa with PVC foam inserts increase screw-holding power

You can also select from a wide range of finishes – standard, smooth natural finish (at right) to sanding gel-coat, ready for paint, or even vacuum-bonded floor covering ready for installation. RMC’s transit floors pass FMVSS/CMVSS 302 or ASTM E-119.

VARTM lends itself to rapid and cost effective prototyping, with turn around times in the range of 3 weeks from art to part.