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Sealing and Encapsulation

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

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Sealing and Encapsulation

TWI has extensive experience (over thirty years) in the field of adhesion and associated surface preparation and can provide expert assistance to any industry sector. It can provide unique surface analysis capability including a state of the art contact angle analyser (surface energy) and portable infra-red spectroscopic assessment (surface chemistry).

TWI also has the in-house capability to evaluate the sealant performance either directly through sensitive gas diffusion measurements or indirectly by assessing the performance of the sealed/encapsulated device in-service or during conditioning/ageing.

Recently TWI was asked to assist a significant aerospace company to evaluate a range of sealant technologies employed within the wing structure with a particular focus on innovative solutions. The outcome was the identification of a number of cost effective routes to bring such technology to market.

For more information, please contact us.