Vacuum Assisted Resin Transfer Molding

Posted on June 16th, 2014 by admin

Sintex-Wausaukee Composites’ (SWC) attention to our customers’ demanding design standards and precise tolerances have allowed us to maintain our status as a Certified Global Supplier of Quality Fiberglass Reinforced Plastic Parts to OEMs for more than 20 years. SWC’s industry leading expertise in Vacuum Assisted Resin Transfer Molding (VARTM) produces innovative and cost-effective solutions for our OEM customers. SWC specializes in VARTM parts for:

Mass transit products like exterior doors with cores
Agricultural equipment such as wheel covers, fenders, hoods, trunk covers and engine covers
Construction equipment such as fenders, hoods, engine covers and cab roofs

The Vacuum Assisted Resin Transfer Molding or VARTM process is used to make unique components in multiple industries – from structurally reinforced hoods and fenders for agricultural and construction equipment to molded core doors for the transportation industry. In a VARTM process, resin is entirely pulled into cavity under vacuum. This molding process allows precise tolerances and detailed shaping.

Why VARTM Glass Reinforced Composites?


Structures made of composites have a long life and need little maintenance.  Composites are corrosion resistant with matrices and binders that prevent environmental attack on fibers and increase resistance to corrosive environments.

High Strength to Weight Ratio

Strength-to-weight ratio is a material’s strength in relation to how much it weighs. Composites have the highest strength-to-weight ratios in structures today. Composites can be made to resist bending in multiple directions or a single direction as needed.


Composites combine high strength and low weight, are non-corrosive and have thermal and electrical insulation properties. Composites can be machined like wood using diamond-tool equipment.

Custom Engineered & Tailored

Composites can be custom tailored for very specific purposes – a particular load, strength in one direction or greater strength to weight ratio. Composites can be designed and optimized to further reduce weight and improve properties by tailoring the binders, fiber type and fiber orientation.

Design Flexibility

Composites can be molded into complex parts that would require sub-assemblies if done in metal. Components can be designed with rigid, semi-rigid, or foam materials. Components can be made fire retardant, or include EMI/RFI shielding.

Hardware & Fixture Integration

Molded composite components can be designed and manufactured to integrate hardware and fixtures into the completed part reducing component assembly and installation costs.

Excellent Cosmetic Finish

Composites can be designed with a high level of surface detail. Parts can be offered in various thickness either coated with high gloss gel coats or with a paintable surface.

General Design Guidelines

Minimum Radius6 mm (0.236 in)
Minimum Draft3 degrees
Minimum Thickness3 mm (0.118 in)
Maximum ThicknessVaries with choice of cores
Typical Reinforcement Loading30 – 35 %
Density (GP resin)1578 kg/m3 (0.057 lb/in3)
Die Lock (Reverse Draft)No

Selection Guidelines

Best used for moderate to high production volumes @ 1,000 – 40,000 parts/year
Consistent, controlled thickness and cross sectional tolerances of +/- 0.5mm
Large structurally reinforced parts requiring two-sided finish
Sintex - Wausaukee Composites

Our Products