Bonding composites
With the increasing demand for lightweight composite materials, the ability to bond together dissimilar materials, such as resins and metals is of growing importance. Although there are many methods available, such as bonding with liquid adhesives or hot-melt adhesives, or mechanical fastening with bolts, manufacturers have been demanding simpler bonding methods that maintain adhesive strength.
To meet these challenges, Showa Denko K.K. (SDK; Tokyo, Japan; www.sdk.co.jp) has developed WelQuick, a film-type adhesive component that eliminates the need for applying liquid components used for reactive adhesives. WelQuick is easy to handle, and shortens bonding time to a few seconds. Conventional adhesives require dozens of minutes, says the company.
WelQuick utilizes the phase change between solid and liquid, and materials can be joined by ultrasonic welding, electromagnetic induction welding and heat welding. It can bond resins (such as polycarbonate, polyethylene terephthalate and nylon) and metals (including aluminum, iron and copper). SDK has confirmed that WelQuick can achieve shear adhesive strength of more than 10 MPa with more than 40 combinations of base materials.