19 августа, 2015 
Malyar Probably the most critical aspect of the introduction of a new process is that of the education and training of the personnel involved. It is vital that the people have a qualitatively correct overall picture of the importance of the different stages of the bonding operation, and of the health and safety considerations. The use of an untrained workforce is likely to cause problems sooner rather than later!
Control of the working environment may be very difficult. Very low temperatures (below, say, 5 °С) or excessive humidity may cause problems with curing or with bond performance. General standards of cleanliness and surface pretreatment procedures must be well defined, but they do share commonality with those used in painting and corrosion protection. Variations from standard curing conditions may result in the adhesive not achieving full strength within a reasonable time-scale. Thus close attention should be paid to temperature, bearing in mind the thermal mass of the components involved; the need to specify heat-curing methods may be necessary. It is often desirable that the adherend temperature should not be lower than that of the surrounding air prior to application of the adhesive, in order to prevent moisture condensing at the interface.
The time elapsed between surface pretreatment and application of the adhesive should generally be kept as short as possible, in order to minimise subsequent contamination. By priming the adherend surfaces involved, either at the job-site or elsewhere, more reliable and reproducible surfaces will be bonded with a greater degree of implied quality.
Adhesive mixing, dispensing and application must be controlled carefully. Automatic dispensing is perhaps preferred although the use of adhesive packed in suitable containers, so that weighing or measurement is not required, is desirable. Application of sufficient, but not excess, adhesive is necessary and consideration of the means of so doing is desirable at an early stage. Insufficient adhesive will result in joint performance and durability problems, whilst a gross excess will hamper assembly and necessitate time-consuming cleanup operations. Joints should be closed in a manner and at a rate that minimises the inclusion of air, whilst with close fitting parts over large bonded areas a means of air escape should be provided. For example, holes may be drilled at regular intervals in large impermeable adherends such as steel plates, a procedure employed in some operations involving external steel plate reinforcement.
As mentioned previously a good joint design will assist the positioning and location of the joint parts, but jigs or permanent mechanical fixings may also be required to hold the components whilst the adhesive cures. Bondline thickness control will also be required, not only to give uniform design thickness but also to prevent displacement of the adhesive under pressure from clamps or jigs. It can be desirable (from a structural point of view) to leave fillets of adhesive surrounding the bonded joint, and these can be tooled appropriately once the joint has been closed.
Physical and mechanical quality control test procedures should ideally be carried out alongside the actual fabrication, and these are reviewed briefly below.
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