Closed Molding

Information About Closed Molding

closedmold-2A technique to further reduce styrene emissions is to cure the resins in a closed mold system. The closed-mold process not only reduces emissions, but also optimizes the glass-to-resin ratio, producing a higher quality laminate. Vacuum bagging and resin infusion are two closed-mold techniques.
Two companies have successfully implemented closed mold systems into their facilities:

  • Phoenix Industries:  The facility converted 60% of its molded part production to closed molding and reduced 80,000 pounds of styrene emissions over two years. (2007)
  • Larson Boats: The company won a 1999 Governor’s Award for Pollution Prevention for developing a closed molding technology for producing boat decks.

More information about closed molding and the importance of reducing styrene emissions can be found in the MnTAP fact sheet, Reducing Volatile Emissions in the Fiber Reinforced Plastics Industry.

SPECIAL PROJECT: Reducing Emissions from FRP Shops

MnTAP is partnering with the Minnesota Pollution Control Agency (MPCA) on an effort to help Minnesota’s fiber-reinforced plastics (FRP) industry reduce styrene emissions. As you may be aware, styrene was recently listed as a chemical of high concern by the Minnesota Department of Health. MnTAP believes that eliminating styrene has environmental and occupational benefits and can lower energy costs, potentially reduce part weight, and reduce reporting requirements and fees. Learn more about the project and how you can participate by clicking here.