Structural Adhesives for High Speed Assembly
By Robert Sevigny, Application Engineer
Structural adhesives are becoming increasingly popular as methods to reduce production costs of
traditional mechanical assembly. User-friendly and cost-efficient, structural adhesives can
permanently assemble similar and dissimilar materials, replacing mechanical fastening, welding,
and brazing processes. Adhesives add only minimal weight to a finished assembly and allow for
adjustment of parts when the proper cure system is used.
Compared to mechanical fasteners and spot welding, structural adhesives provide appliance
manufacturers with many benefits. Adhesive assembly is typically less costly than mechanical
fastening methods. Assemblies bonded with adhesives benefit from an even distribution of load
stresses which reduces fatigue failures experienced with bolted, riveted, or welded assemblies.
On dissimilar metallic assemblies, adhesives can act as galvanic insulating materials, protecting
the assembly against corrosion. Structural adhesives can also improve the appearance of dryer,
air conditioner, and other appliance cabinets, offering a cosmetically perfect look while eliminating
the need to retouch dimpled or pitted areas around steel weld points.
Selecting an adhesive that will reduce costs and ensure product integrity can be a challenging
assignment. To be effective in the selection process, engineers must consider all factors that will
influence the performance of the bonded assembly. Such factors include joint design and
stresses, substrate selection, and surface preparation methods.
Joint designs for other fastening methods may not be suitable for adhesive bonding. Adhesive
joints must be specifically designed to generate the maximum strength and durability, and
minimize stress concentration. Engineers should take into consideration manufacturing
capabilities, production costs, and the desired final appearance of the assembly.