Composites: Trouble’s in the air

In the case of the composites industry versus the clean air movement, the industry in Canada, with the help of the Canadian Plastics Industry Association (CPIA), has successfully made its case with the current round of government regulators. Regulations on occupational exposure limits and air emissions which have been updated over the last few years could have crippled the industry, but instead are merely causing some shifts in processes and materials.

The composites fabrication segment is in transition, moving from open-mold processes which release volatile organic compounds (VOCs) to closed-mold processes with new formulations which release far fewer contaminants into the air.

The reinforced plastics fabricators using open mold processes, such as spray-up and hand lay-up, are most affected by VOC regulations. Unsaturated polyester resin is the most common resin for these processes, and it can contain up to 45% styrene monomer. Newer low-styrene formulations drop that figure to 30% or 35%.

Banish odor inside and out

Composites fabricators have to manage emissions on two fronts. The occupational exposure limits are a safety issue for those working with the parts inside the plant. Outside the plant, airborne contaminants are also monitored and subject to control. Rules for both types of emissions are set at the provincial level, so there is no consistency across Canada, and no harmonization with U.S. either.

“It seems for the most part that occupational exposure limits (OELs) have not been a huge problem,” reports Alan Gardiner, v-p sales and marketing of Min-Chem Canada Inc. (Oakville, ON), a composites industry supplier. “Some adaptations in process equipment and raw materials have helped.”

Some of the same process changes and low-VOC resin formulations also help with outside air quality. Gardiner sees the options for compliance with the airborne emissions regulations as:

Install a stack to treat the emissions. This is beyond the budget of smaller companies which make up the bulk of the industry in Canada.

Change to low-VOC raw materials. Resin producers have responded with low-VOC formulations, but they tend to be more costly.

Change to spray equipment with reduced atomization. Fluid impingement technology from Magnum Venus Products, for example, is said to reduce emissions to levels below U.S. EPA requirements.

Change to a closed-mold process. Some of the newer options such as vacuum-assisted resin transfer molding (RTM) are not that much more expensive than traditional open-mold processes, says Gardiner.

“Most fabricators will have to adopt all or most of these techniques,” he says.

“I can certainly envision a future of only closed-mold processes,” adds Stephane Baffier, director of CPIA’s composites council.

Being reasonable about clean air

CPIA has been very busy on both federal and provincial fronts, attempting to steer new regulations regarding exposure limits and airborne emission toward realistic, achievable targets. “Frankly, we haven’t been receiving a lot of support from the industry,” says Baffier. “There are a few companies — very few — that have been supportive. A lot of the industry is just happy to let us carry the torch.”

CPIA has negotiated with about seven or eight provinces in recent years as the provincial governments have updated their occupational exposure limits.

In those cases where the OEL is not technically or economically feasible, each company would have to plead its own case for non-compliance, says Baffier, and that certainly doesn’t fit with the concept of a level playing field.

Despite the industry’s efforts at compliance and negotiation of reasonable limits, if the heavy hand of enforcement were to fall on the composites sector, many might be found non-compliant. And that possibility hangs over the industry.