Page 206 - Handbook of Adhesives and Sealants

Chapter
5

Quality Control and Nondestructive Tests

5.1 Introduction
In this chapter, various methods of controlling the consistency of the
sealing or bonding operation will be introduced. These processes usu-
ally fall into the categories of quality control or nondestructive testing.
Although some are sophisticated, many of these processes do not re-
quire 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 ad-
hesive or sealant will be the main subject of this chapter. Important
processes, such as training and plant cleanliness, that need to be con-
sidered even before the manufacturing operation are included in this
discussion. Quality control methods that are commonly used for check-
ing incoming materials and controlling the various processes are re-
viewed. 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, signif-
icant costs could occur. For adhesives and sealants, quality control
must be defined in its broadest sense. This consists of defining the
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