The Importance of Viscoelasticity in Pressure Sensitive Adhesive Tapes
Viscoelasticity is a critical characteristic of pressure sensitive adhesive tapes (PSA tapes), but not all PSA tapes have the same viscoelastic properties. Some PSA tapes have a greater viscoelasticity than others, giving them properties that make them more suitable for specific applications. What makes viscoelasticity an important factor in PSA tape performance? Are you using the right tapes for your application? Find out more about how this capability can heavily impact the performance of your PSA tape.
What is Viscoelasticity in PSA Tapes?
Viscoelastic is a term that refers to a material having the properties of both solids and liquids. The term is made up of two words:
Viscous, meaning that something has a thick, sticky consistency that lies somewhere between a solid and liquid.
Elastic, meaning that a material is able to return to its normal shape on its own after it has become deformed.
When it comes to PSA tapes, viscoelasticity is what makes PSA tapes sticky, have good tack, and still be able to maintain their shape when forces are applied to them. It’s the viscousness of the adhesive components in PSA tapes that allow for good contact during bonding. It allows the adhesive to flow into microscopic pores of the substrate. The solid elastic components of PSA tapes help the adhesive withstand shear, tensile stresses, and cleavage and peel forces that can impact performance over time.
PSA tapes hold their shape but will eventually wet out the surface to which they are adhered. Some of the things that effect the time the adhesive takes to wet out on the surface include:
Temperature (most PSAs require temperatures above 50ºF and below 120ºF for ideal initial bonding)
The pressure placed on them
The dwell time
The Importance of Viscoelasticity in PSA Tapes
The viscoelasticity of pressure-sensitive adhesive tapes influences their performance and behavior when used in various applications. It also makes this bonding solution better than many other alternatives. PSA tapes maintain their viscoelasticity better than liquid adhesives like epoxies, hot melts, and cyanoacrylates which turn into solids upon curing or phase change. These can be prone to becoming brittle and fracture when exposed to certain stresses and environmental conditions.
Viscoelastic PSA tapes have several properties that make them ideal for many different types of bonding applications:
Wet out: for surfaces that are rough or uneven, choose a PSA that is viscoelastic as it will flow into those areas better.
Sealing: viscoelastic PSA tapes can fill gaps and form a tight seal between the surfaces they are bonding.
Dampening properties: viscoelastic materials dissipate energy, which allows them to dampen sounds and vibrations.
Ease of application: the viscoelastic nature of PSA tapes makes them easy to apply with pressure instead of having to use heat or to liquify the adhesive or relying on mixing liquid base and activators to cure the adhesive.
While all PSA tapes are viscoelastic, the best example of the benefits of viscoelasticity are 3M™ VHB™ Acrylic Foam tapes. These tapes take the benefits of viscoelasticity to the extreme by enabling the ability to bond to a wide variety of substrates, including polyethylene, in the case of 3M™ VHB™ LSE Tape Series, while providing very high strength against dynamic stresses.
Choose a Viscoelastic Tape for Your Application
Understanding viscoelasticity is essential because it plays a pivotal role in determining a PSA tape's performance, making it a crucial factor in selecting the right tape for specific applications. Whether you're looking for superior performance or ease of application, PSA tapes offer both across a wide range of substrates. Choosing the right PSA tape with the ideal viscoelastic properties can significantly impact the success of your bonding applications and elevate performance. If you need help choosing the right PSA tape for your application, get in touch with our bonding specialists today.