Most often, this process results in high-quality materials. Occasionally, problems arise and the final product may not meet required specification. To define the nature and extent of the problem, a series of tests must be performed. Routine adhesive testing-such as coating weight/consistency, peel adhesion, tack, and/or shear-can identify adhesive performance issues. However, these tests alone may not lead to the source of the problem and the eventual resolution of a quality issue.
It is up to the investigator to isolate the root cause to a physical/surface-related issue (e.g., contamination) or a bulk adhesive chemistry problem (e.g., improper formulation) while using knowledge of the process and application to solve a problem.