18.1 Introduction

The production processes that are used to convert the liquid adhesive or sealant into a practical working joint are important considerations in the overall design of the bonding system. These processes include storage of the materials, metering and mixing, application, fixturing of parts, and setting of the adhesive or sealant material. The multiple methods available can represent both an advantage and a hindrance to the end-user. There is a great likelihood that the user will find a cost effective process for the specific application. However, choosing the wrong process can have just as dire consequences as choosing the wrong adhesive.

Deliberations concerning the exact processes and equipment to be employed are, unfortunately, often left to the end of the decision making process. Selection of the substrate, adhesive, joint design, and surface pre-treatment are often considered first. However, considerations regarding the application and processing of the adhesive or sealant should be made as early in the process as possible because they alone may:

• Restrict the degrees of freedom in designing the end product

• Widen or narrow the types of adhesives that can be considered

• Affect the quality and reproducibility of the joint

• Affect the total assembly cost

The production methods that are at the disposal of the user may affect the production rate, simplicity, economy, and overall bond quality. The simpler the processes, the less training the operators will require and the more reliable will be the results. Several generic factors must be considered in the selection of the...