FOCUS ON JOINING TECHNOLOGIES
Image : Shutterstock . com .
A STRONG SEAL
We outline the benefits of industrial adhesives and sealants for a wide range of metallic bonding and sealing applications .
“ The adhesives and sealant industry is continuously innovating with debonding technologies to repair , reuse , repurpose and / or recycle to create a circular system .”
Today ’ s adhesives and sealants are based on a wide variety of natural and synthetic technologies . These numerous formulating options allow products to be tailored that match the requirements of a huge range of disparate substrates and applications .
An adhesive is a compound that adheres or bonds two or more substrates together . Adhesives may come from either natural or synthetic sources . Adhesion may occur either by mechanical means , in which the adhesive works its way into small pores of the substrate , or by one of several other chemical mechanisms . In some cases , an actual chemical bond occurs between adhesive and substrate . In others , intermolecular forces hold the substances together . A third involves the moisture-aided diffusion of the glue into the substrate , followed by hardening . Good wetting of the surface is a pre-requisite for this kind of adhesion .
A sealant is a soft , pliable material that is used to seal cracks or joints where structural strength is not required . The sealant , initially a fluid or semi-fluid ( or alternatively hot applied ) placed between two opposing solid materials , becomes solid itself ( by solvent evaporation , chemical reaction or both ), and bonds to the surfaces to which it is applied .
It therefore accommodates joint movement without adhesion loss . The sealant ’ s purpose is to prevent excessive absorption of water , penetration of other liquids , gaseous substances or airborne particulates . A sealant has the adhesive and cohesive properties to form a permanent seal .
“ Adhesives and sealants share similar characteristics and perform similar roles . The main difference between the two is that sealants typically have lower strength and higher elongation than adhesives ,” explained FEICA ( the Association of the European Adhesive and Sealant Industry ).
Worker using glue gun with adhesive to fix metal steel on roof ( Shutterstock . com ).
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