DESIGN AND STRENGTH
The reliability of PSA tapes is tightly linked to selecting the right chemistry for your application environment and usage loads. PSA tapes are viscoelastic and the properties of polymers and adhesives are a function of two things: temperature and rate of deformation. Hot temperatures and a slow rate of deformation produce a viscous effect. Cold temperatures and a fast rate of deformation produce an elastic effect. This rate dependency enables PSA tapes to give you the benefits of noise and sound dampening, along with durability and the ability to conform to complex surfaces and designs.
Because of their viscoelasticity, PSA tapes may allow you to avoid design constraints presented by traditional metal fasteners. For example, when bolts are applied at discrete points, your design constraints include the bolt’s ultimate strength and the stress concentrations formed at the holes in the adjoining parts. On the other hand, PSA tapes are applied across an entire surface to form a continuous bond without holes. So your design constrains involve only the strength and durability of the adhesive.
There are several standardized tests that measure the strength of PSA tapes. The peel adhesion test measures the force required to break the bond between the adhesive and substrate. This test is similar to the ultimate tensile strength evaluation for traditional metal fasteners. The static sheer test, which is similar to a creep test, applies a constant load to PSA tapes on a surface at prescribed angles. Failure is determined by excessive deformation.
In addition, the probe tack test quantifies the force needed to pull a standardized probe at a specified rate from an adhesive surface.