5.1 Introduction

In this chapter, various methods of controlling the consistency of the sealing or bonding operation will be introduced. These processes usually fall into the categories of quality control or nondestructive testing. Although some are sophisticated, many of these processes do not require advanced equipment or knowledge. Simple equipment, visual examination, and common sense are the main tools in most quality control departments. They are supported by strong specifications and proper training.

The control processes that are practiced by the end-user of the adhesive or sealant will be the main subject of this chapter. Important processes, such as training and plant cleanliness, that need to be considered even before the manufacturing operation are included in this discussion. Quality control methods that are commonly used for checking incoming materials and controlling the various processes are reviewed. Bond inspection techniques will include both destructive and nondestructive tests. Analytical methods will also be described that can be used to examine failed joints for cause of failure.

5.2 Quality Control

Quality control encompasses all of the processes and activities that ensure adequate quality in the final product. Quality control is very important when using adhesives or sealants because once fully bonded, joints are difficult to take apart or correct. By the time it takes to notice that one step in the bonding process is out of control, significant costs could occur. For adhesives and sealants, quality control must be defined in its broadest sense. This consists of defining the means to prevent problems...