Open Molding

FRP shops using an open mold process can make product or process changes to reduce air emissions. Opportunities for reducing styrene emissions include:

• Implement a controlled spraying program.
• Improve raw material monitoring through better processing control.
• Substitute low-styrene emission resins.
• Upgrade resin and gelcoat application equipment.

Emissions Estimating The American Composites Manufacturers Association (ACMA) Styrene Emissions Test Project produced a comprehensive body of information on emissions from open molding, including technical support guides and information on emissions factors.

Controlled Spraying Handbook: Composites Open Molding Resin & Gel Coat Application. This ACMA resource provides training guidelines for spray operators in the open molding companies industry, where styrene based resin and gel coat materials are used.

Controlled Spraying and Laser Touch in the Fiber Reinforced Plastics Industry Controlled spraying significantly reduces styrene emissions from open mold fiber reinforced application processes, benefiting employee health, the manufacturing operation and the natural environment by increasing materials transfer efficiency. The improved accuracy and consistency provided by proper training and the use of the Laser Touch ensures material placement, also maximizing transfer efficiency.

Fiberglas Fabricators Upgrades Open Mold Processing Equipment This FRP shop adopted nonatomized equipment to replace spray equipment in open mold process and added raw material monitoring equipment. Styrene emissions were reduced by 50,400 pounds annually, meeting the NESHAP requirements.

Fiber Reinforced Plastics Shop Complies with New Air Permit Regulations Sunrise Fiberglass Company replaced spray equipment with nonatomized equipment in open mold process. Low styrene resin replaced traditional resin. The company reduced its styrene emissions by 43 percent, meeting the requirements of its new air permit without lost production time or excess capital costs.

Reducing Volatile Emissions in the Fiber Reinforced Plastics Industry Most FRP processing facilities are major sources of volatile emissions. Their emissions include styrene, the volatile component of polyester resin and gelcoat; and acetone, a solvent used to clean tools and other surfaces contaminated with resin. This fact sheet discusses opportunities for reducing these emissions. See the sections on low-styrene emission resins, upgrading resin and gelcoat application equipment, controlled spraying and raw material monitoring.

Source Reduction and Recycling Opportunities for a Fiberglass Reinforced Plastics Shop Astoria Industries employs approximately 45 people and manufactures fiber reinforced plastic (FRP) components for truck utility bodies and livestock trailers. The manufacturing process uses an open-mold, spray lay-up process, which involves applying a fiberglass and catalyzed polyester resin mixture onto open molds.