Vacuum Infused Molding

Vacuum Infused Molding: VARTM, VIP

The various types of vacuum infused molding are well-suited for products with high strength-to-weight requirements, or with slight design returns, edge overhangs, or high draft angles that would cause die-locks on rigid B-side mold surfaces.

Vacuum Infusion Processing

We recommend vacuum infused molding (also known as VARTM, Vacuum Assisted Resin Transfer Molding) when there is a critical need for control of glass ratio.

VIP is a vacuum-assisted, closed-mold resin processes. For compression on the B-side surface, VIP uses a flexible sheet or re-usable bag. This yields increased laminate compression, a higher glass-to-resin ratio, and excellent strength-to-weight characteristics.

Vacuum infused molding is performed with pressure assistance inside the cavity of a closed mold. A VIM mold has two rigid surfaces; the flexible film is sealed to the rigid surface. In addition, there are two vents to the sealed mold. One vent is used to remove air from the mold cavity and another to permit the liquid resin to be drawn into the cavity through negative pressure. Once the resin ins cured, the part is removed from the rigid mold revealing a uniform composite part.

Foam or wood core and stiffeners are commonly used as reinforcement with VIM. These reinforcements produce light weight, strong parts without increasing laminate thickness. This can reduce manufacturing cost for larger, rigid parts.

  • Best suited for mid-volume production in the range of 200 to 5,000 parts per year*
  • One good side. Very large to very small parts.
  • Pre-placed of reinforcement can be employed to achieve optimum strength-weight ratios
  • In-mold gel coat finishes can be employed for desired cosmetic finishes
  • Environmentally-friendly – this closed mold process involves no resin exposure

*Volume recommendations are averages and provided only as a general guideline. Actual volume efficiencies are a more complex matter requiring detailed statstics about the part to manufactured.

Center of Excellence for Low Pressure Molding