The need to seal and/or isolate components either from other components or from the atmosphere is a major requirement in many products. The general term sealing and encapsulation covers many different applications and materials.
Sealants and adhesives are sometimes confused as being the same. However, the primary function of an adhesive is to join and carry load whereas a sealant is required to seal either a set path (joint) or an area/volume (encapsulant/potting agent) and joining is merely a by-product of the sealing operation.
Sealants will very often have low/poor mechanical properties and can be soft and conformal. Despite the differences between sealants and adhesives, for both to function effectively they must share the key property of being able to fully wet out a surface prior to curing/hardening.
Sealants/encapsulants are used in many industry sectors but probably the most relevant to TWI are aerospace, medical and electronic although general engineering and automotive have key requirements too. Key challenges relate to developing the correct surface to maximise the wetting of the sealant to substrate, application of the sealant, controlling the rate and time of cure and durability. Cost can also play a critical role, especially in sectors where margins are tight such as the building and construction and automotive sector. TWI assists in all of the above areas