Structural Adhesives – Tough, Reliable and Multipurpose
What are Structural Adhesives?
Sometimes they’re described by the way they cure, like UV curable, pressure sensitive, moisture curable, two-component or heat curable. (Note: This is actually a secondary classification for practical purposes. Curing types relate directly to assembly process issues. A UV curable adhesive is cured using UV after the adhesive is in place, etc.)
In this case 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 which 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 which can be used for structural applications including acrylics, epoxies, urethanes, modified epoxies etc. The reasons for using adhesives in place of (or in addition to) mechanical fastenings vary by application. The other primary issue related to the use of structural adhesives is design and performance-related. Structural adhesives 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 in the use of structural adhesives. 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. This particular application of structural adhesives is now common.
Core efficiencies in the use 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 joins, provide strength to key components of assemblies . Cured structural adhesives can also act as sound dampers.
There are some major design issues which are quite literally key elements of design in areas like aerospace, where assembly flexibility and efficient stress distribution are primary performance issues for materials under very high and variable loads. Structural adhesives are perfect for these applications, providing specification based solutions to design issues.
If you’re looking for a solution to a design or performance issue, start looking at structural adhesives. There’s not much they can’t do, and remember you can always ask the manufacturers for assistance if you’re stuck with a problem.
For further help with design and adhesive selection, please contact Permabond.