Plastic component supplier to the automotive industry, Polynorm, is using
Araldite's 4910 adhesive to bond a front radiator grill and engine hood
assembly, made from Menzolit 5320 Class A composite, on a range of Scania
trucks. Bonding was chosen in place of welding or riveting as it provided
better vibration resistance and reduced stress concentrations.
Each assembly involved four simple lap joints. Two joints bonded
stiffeners running the full length of the assembly on each side. Two
smaller inserts were also bonded, the whole process being completed in
ambient conditions.
Polynorm engineer, Gordon McDonough says the choice of adhesive was
influenced by a number of factors, principally the elimination of
volatile primers., which improved the health & safety performance of the
process. The composite required only the simplest of pre-treatments prior
to bonding.
The bonded joint has to withstand temperatures as high as 80°C during the
paint cycle, not to mention wide swings in ambient temperature and
humidity during service, and road vibration effects over the entire life
of the vehicle.