ASC: Convention’s focus is a breath of fresh air

General Motors’ Wayne Reeder considers the challenges facing the use of adhesives and sealants in automotives, and why improving the interior air quality is paramount

The combination of pressure from consumers, environmental groups and government has spurred car manufacturers on in their pursuit of lightweight vehicles. As metal components are replaced and lighter plastic parts adopted, so too are a myriad of adhesives and sealants.

Whether they are used in the door panels and dashboard or the seats and steering wheel, their application is becoming increasingly widespread throughout the automotive industry. Adhesive bonding is still considered the more expensive alternative to welding, riveting or other types of fastening. However, it is increasingly being required in more and more applications as dissimilar materials are bonded to achieve mass reduction.

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Wayne Reeder, senior product engineer at General Motors (GM) and a speaker at the Adhesive and Sealant Council’s upcoming Fall Convention & EXPO, says that car manufacturers are demanding even more from the materials used in their production.

There are many challenges involved when trying to take weight out of a car to improve fuel efficiency, and thereby reducing harmful emissions, he says.

“One issue I’m going to cover is the use of anti-flutter adhesives that expand and eliminate noise in the vehicle. When they then cool down and contract, we don’t want to see any bond-line ‘read-through’ of the adhesive outline on the surface; as the adhesive cools, we also don’t want there to be any movement of the panel it’s attached to.”

Reeder is addressing this at the upcoming ASC convention, as well as other challenges for adhesives suppliers and issues they will have to overcome in the year ahead.

These include structural adhesives and metal bonding, interior trim and underhood adhesives, as well as the elimination of solvents from adhesives and primers. Equally, with cars getting more efficient, the engines are running hotter so there is a lot more heat under the bonnet than there used to be – all of which has implications for the adhesives market, he adds.

One of the items that tops the agenda – and the main subject of his paper at the ASC event – is the vehicle interior air quality (VIAQ) and how adhesives may be affected by the alteration of some of the substrates.

“This is a big issue facing the industry,” says Reeder. “We’re still expected to get excellent bonding, but to improve the interior air quality, we have to look at the alteration of some of the substrates and the surface energies.”

VIAQ is a major consideration for all car manufacturers, he says, as emissions from components and materials used within the car can have a detrimental effect on both the health, safety and comfort of the driver and passengers.

“The situation is getting better because suppliers of the plastics are modifying some of their manufacturing requirements and getting more proficient at eliminating some of these solvents from products used in cars.”

Reeder points out that GM has some very stringent standards that must be met for the use of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs)

“There are many specifications that we put on our materials so we can meet a specific set of requirements and limit the various volatiles,” he says.

Among these standards to monitor VOCs and SVOCs in vehicle interiors are GMW15654, GMW15634 and GMW16583, adds Reeder. These partly help to ensure that all VOCs from C4-C14 and SVOCs from C14-C36 are restricted and kept below an acceptable level, along with specific levels of formaldehyde and acetaldehyde.

“Many materials fail to meet our standards,” says Reeder, “so what we’re then doing is setting a timeline for the materials that do not meet them so that suppliers have the chance to improve the results and get them in the range they need to be. New suppliers need to show us that they can meet those requirements within a reasonable time. As long as we are getting these materials right and streamlining them, we can eliminate any problems in the future – that’s the goal.”

These high standards are being particularly steered by many of the Asian governments, such as South Korea and China, which have new regulations coming into force in 2015. “They have previously been voluntary, but we anticipate them to be mandatory starting next year in those countries. This means that any cars that they import have to meet these requirements. That is driving us to meet those requirements with car manufacturers across the US too.”