5.4.1 Dosification and Bonding Process

A wide variety of dosification methods may need to be factored into the choice of adhesive for a particular assembly. Additionally, the dispensing method may affect the design of the assembly, as some methods for dispensing may not be practical for some assemblies. The final consideration is the quality or aesthetics of the final product.

The following factors should be considered when selecting the adhesive and the dispensing method:

• Size and geometry of the parts to be bonded
• Orientation of the surfaces to be bonded (horizontal/vertical)
• Areas to which the adhesive is to be applied
• Number of assemblies to be produced
• Required production speed
• Cure time of the adhesive as it relates to the total area to be bonded
• Viscosity or rheology of the adhesive
• Form of the adhesive (liquid, paste, hotmelt, etc.)
• Chemical compatibility with wetted components

The dosification method – manual/automatic dispensing or a combination of the two – is usually decided upon based on overall cost (cost-saving, additional investment, etc.), size of production, accuracy of dispensing and the importance of consistently repeatable assemblies. Whenever practical, automated dispensing lines should be incorporated into the adhesive process to maximise efficiency and accuracy and to minimise costs.