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How can the quality of an adhesively bonded joint be controlled?


Frequently Asked Questions

An adhesive joint consists of several different parts that in total make an adhesive joint 'system'. The parts of the joint system include:

  • the adhesive
  • the adherents or substrate materials
  • the surface treatment
  • the joint design.

The quality of the joint is best controlled by considering all parts of the joint system and then making sure that these parts are checked, tested and controlled, so that they conform to previously defined requirements or standards.

As well as the parts of the joint system, there are the 'phases' involved in producing the joint. There are four main phases:

  • Design
  • Material selection
  • Fabrication
  • Inspection

and these cover the actual activities performed in producing the joint. Control of the activities in these phases is equally as important as control of the parts of the joint system.

This focus on control of both the constituent parts of the joint system and the phases in production arises because it can be difficult to effectively inspect an adhesive joint after it has been made. This difficulty in inspection occurs because the available non-destructive test and evaluation techniques are not always able to find all of the potential defects that could occur within an adhesive joint. Since post-production inspection cannot always guarantee defect free joints, it becomes necessary to have good control of all the parts of the joint system prior to and during production.

In order for an adhesive joint to have the desired quality there needs to be a good philosophy and positive attitude to quality assurance within the organisation making the joints, backed up by good education and understanding of the processes involved in making an adhesive joint. Standards that set out the requirements for QA of adhesive joints are in the draft stage with the International Organisation for Standards (ISO 21368).

Additional information on QA and training can be found here:

For more information please email: