As a manufacturer of both rigid and flexible adhesive systems, we have found that when it comes to bonding mass transit and commercial vehicles, our flexible Formoa 017FE is the best solution.
Using Formoa 017FE (with its 300 – 500% elongation) eliminates any concerns over twisting, bumping and rolling etc because the flexible adhesive absorbs movement within its internal structure, rather than transferring all force to the bond interface. Formoa 017FE adhesive has a lap shear strength of 2.5N/mm2 – equal to approximately 0.25kg/mm2. The bond area to secure the body to the chassis is 60mm x 4527mm x 2mm. If we assume a minimum bond width of 25mm, the force to remove the body (in shear) would equate to approximately 56,500kg!
All our Formoa products have superior durability and do not embrittle with age. We have been successfully bonding one-piece composite and plywood floors in buses for 12 years, and many of our buses and truck bodies have been put through full durability life-cycle testing at Milbrook and Altoona in the US. We conduct all our lap shear testing on-site at 6mm/minute as this represents the closest value experienced in real life vehicle tests we have conducted.
Formoa adhesives cure by a reaction with atmospheric moisture, however, we do not recommend spraying the bond/adhesive area with water as over saturation can actually prolong the adhesion build up values – the amount of moisture required to start a reaction is very small. Cure is from the outside to inside and full cure of a 25mm wide bond will typically take seven days. But with Formoa 017FE one third of end strength is reached in the first phase (24 hours).
Formoa adhesive chemistry will give you greater manufacturing process tolerance in the workplace, more consistent summer/winter performance, easy extrudability, and long term performance combined with economic viability. Get in touch if you want to use Formoa 017FE or any other of our Formoa products.