Materials supplier Dow Corning unveils new silicone and elastomer technologies aimed at reducing costs and increasing material performance in underhood applications here at the 2015 SAE World Congress.
The company says its EA-7100 adhesive is a breakthrough in silicone chemistry that greatly expands design options for automotive electronic assemblies such as engine control modules, sensors and lighting modules by bonding strongly to a wider variety of substrate materials.
The adhesive features radical new chemistry that allows up to 50% faster cure times than conventional heat-cure platinum catalyzed silicone adhesive systems, officials say.
“It lets you adhere to things you couldn’t adhere to. It sticks to almost anything with good structural ability and shortens cycle times,” Kate Johnson, application engineering specialist-Electronics Solutions at Dow Corning, says in an interview.
The one-part, heat-cure adhesive can speed production because it cures rapidly from the inside out and at lower temperatures. That can speed up assembly-line processing and reduce energy costs associated with manufacturing. Heat can accelerate the cure time for the adhesive, but the material’s dramatically new chemistry allows use of smaller, lower-temperature curing ovens that consume less energy.
Because the new silicone adhesive is so sticky, it allows design engineers to use a bigger menu of substrate materials when designing new ECMs and other underhood electronic devices. That is another potential cost-saver, says J. Fred Buether, marketing director-Americas Transportation Electronics at Dow Corning.
The adhesive forms strong bonds to metals, ceramics, glass and laminates, in addition to plastics that normally pose problems for silicone, such as polyethylene, polycarbonate and acetal. Depending on the application, the material often can bond to these substrates without pre-treatment or extensive cleaning, officials say.
Dow Corning also introduces a revised Fluorosilicone elastomer for underhood applications at SAE.
Temperature-resistant Fluorosilicone rubber has been used for decades under the hood where it is designed to withstand continuous temperatures of 292° F (200° C) in continuous use in components used in fuel systems, airflow management, engines, turbocharger hoses, liners and numerous types of seals, says Craig Gross, a senior application engineer at Dow Corning.
However, increasingly crowded engine compartments and more power-dense forced-induction engines are substantially raising underhood temperatures, so Dow Corning is showing off a new Silastic Fluorosilicone Rubber portfolio at SAE that Gross says can meet long-term performance requirements of 428° F (220° C).