Structural Adhesives – Tough, Reliable and Multipurpose
What are Structural Adhesives?
Adhesives are classified in many different ways, usually on the basis of their chemical composition. Different classes include cyanoacrylate, epoxy, acrylic, urethane etc…. Sometimes they’re described by the way they cure, like UV curable, pressure sensitive, moisture curable, two-component or heat curable. The term “structural adhesive” refers to the role the adhesive plays as part of the physical structure of joined surfaces.
A more formal definition of structural adhesive is: An adhesive that forms bonds that will bear loads of considerable magnitude; a structural adhesive will not fail when a bonded joint prepared from the thickness of metal, or other material typical for that industry, is stressed to its yield point.
Structural adhesives are therefore literally part of the structure of their assemblies. They’re designed to meet performance specifications for the specific requirements of the assembly. This is an often critical issue in bonding and is extremely important in ensuring structural integrity.
Adhesives used for structural applications include acrylics, epoxies, urethanes, modified epoxies etc. The reasons for using adhesives in place of (or in addition to) mechanical fastenings vary by application. They have significant design and performance benefits in many applications. In the automotive, aerospace, and transportation industries, one of the key uses of structural adhesives is that the adhesives reduce the weight of the assembly. This weight reduction improves performance, simplifies, and in many cases, drastically reduces the cost of assembly and provides appropriate load-bearing strength without compromising quality.
There are also major structural improvement benefits; for example, ferrite magnets used in electric motors are vulnerable to shattering at the clip points. Using structural adhesives to add tensile strength to the magnets significantly increases the product life of these motors.
Core efficiencies of structural adhesives include major design benefits in universal applications like office furniture, workstation configuration elements like partitions, and even high-load base, demanding assemblies like trailer trucks. The adhesives replace costly mechanical fasteners and provide strength to key components of assemblies. Cured adhesives can also act as sound dampers.
Adhesives are ideal where assembly flexibility and efficient stress distribution are primary performance issues for materials under very high and variable loads. Examples of these types of applications are found throughout the aerospace and transportation industries.
For further help with design and adhesive selection, please contact Permabond.