An ever growing range of new adhesives is being developed to keep pace not only with the specific needs and levels of performance required by new technologies, but also as a result of their taking over the roles of mechanical fasteners in manufacture and assembly in many sectors.
This growth rate, together with constantly expanding regulations regarding safety, standards, and compliance, has highlighted the importance of force measurement in adhesive testing, and the data it provides about components and assemblies, to ensure optimum adhesion and performance in existing and new areas while also assisting with product design, quality control, and problem solving in problematic areas.
Force measurement benefits both adhesive manufacturers and end users by lessening risks and gathering better insight into what the adhesive’s performance is likely to be like when used in any given application. This information, while valuable in most applications, becomes increasingly important (and more vital in terms of meeting compliance regulations) when being used for application in sensitive areas such as medical applications and aerospace.
Unlike materials testing, which analyzes a wide range of factors like elasticity, elongation, strain and stress, force measurement tests factors like the compression strength of adhesives (especially when adhesive tape is used) and its tensile and pull-off strength when two substrates have been bonded, to enable a projection of the performance which can be expected from the adhesive in specific applications.
Various processes are used to gather information in order to carry out force measurement testing in different situations by relying on physical motion and a collection of measurements, while others involve equipment. The first approach includes peel tests, one of which, the T-peel test, is often used for adhesive labels in the packaging sector. It focuses on the separation force of the labels to determine whether the adhesive bond is likely to separate prematurely; if the bond can hold its strength yet be easily removed at the right time; and if its performance remains consistent in different batches.
Another peel test, the loop tack test, focuses instead on how evenly the adhesive has been spread down the length of the tape or bond, as irregularity in the amount of adhesive applied in different areas can affect the integrity and performance of the bond.
The coefficient of friction test performs a completely different task. It’s focus is on coatings, where it helps quantify the coating’s frictional properties so as to ensure consistency in manufacturing regardless of whether the coating is being used to protect an object, or to bring about a required sliding resistance or tactile feel on it.