Types of Pressure Sensitive Adhesives
Pressure sensitive adhesives (PSAs) are an incredibly versatile and widely used adhesive material. Many of these adhesives are based either on acrylics or rubber. Choosing which type of PSA to use often depends on the application. Acrylics and rubber adhesives have a number of distinct differences that should be considered when selecting a PSA.
Acrylic Based PSA
Acrylic based PSAs are composed of acrylic polymers and often contain copolymers additives. These adhesives are designed to form a bond between two surfaces by creating a strong, yet flexible, bond between them. They have good adhesion to a variety of surfaces. Acrylic based PSAs are typically more heat and solvent resistant than rubber based PSAs and are often used in applications where the adhesive will be exposed to harsh environments. Additionally, acrylic based PSAs typically have better UV stability than rubber based PSAs, making them a good choice for outdoor applications.
Pres-On’s high tack acrylic PSAs are used for applications where a permanent bond is needed. Prior to applying pressure, they have a gentle, sticky feel that can be used to test alignment and is able to be repositioned on most surfaces. Once pressure is applied, the adhesive will need a few hours to settle or cure. In general, after 4-6 hours it is no longer repositionable, and after 24 hours, the bond is completely permanent. See disclaimer below.
Rubber Based PSA
In comparison, rubber based PSAs are composed of natural or synthetic rubber polymers and often contain additives. They are often used in applications where the adhesive needs to be flexible and elastic, such as in packaging applications. They have good adhesion to many surfaces, but are typically not as heat or solvent resistant as acrylic based PSAs. Rubber based PSAs also typically have better adhesion to low surface energy surfaces, such as plastics and rubber, than acrylic based PSAs. They are a more versatile option, but the longevity is not that of the acrylic based adhesive.
Pres-On’s super tack rubber based PSAs are designed to provide a permanent bond between two surfaces. Prior to applying pressure, they have a strong sticky grip and is not repositionable without loss of tack on the second setting. The rubber based adhesive has a higher initial tack or adhesive grip. Once pressure is applied, the adhesive is instantly permanent and cannot be removed with risk of damaging certain surfaces. See disclaimer below.
Surface Energy
When selecting a PSA for an application, it is important to consider the surface energy of the material being bonded. The surface energy of a material is a measure of the attraction between the molecules at the surface of the material and the molecules of the adhesive. Acrylic based PSAs typically have higher surface energy than rubber based PSAs, meaning they are better suited for bonding to high surface energy surfaces such as metals and glass, while rubber based PSAs are better suited for bonding to low surface energy surfaces such as plastics and rubber.
Which is Better?
In conclusion, acrylic based PSAs and rubber based PSAs have distinct differences that should be taken into consideration when selecting an adhesive for a specific application. Acrylic based PSAs are typically more heat and solvent resistant, while rubber based PSAs are typically more flexible and elastic. The surface energy of the material being bonded should also be taken into consideration, as acrylic based PSAs are better suited for high surface energy surfaces, while rubber based PSAs are better suited for low surface energy surfaces.
If you are having trouble deciding which Pressure Sensitive Adhesive would be best for your upcoming project, please contact us.
Disclaimers:
Acrylic PSA: depending on your application surface, removing the acrylic based adhesive foam tape after 24 hours may cause damage. Either by failure of the foam (tearing) or failure of the surface (i.e. drywall tearing off with removed foam tape). It is important to always test a small section in a discrete area before full use of any product.
Rubber PSA: depending on your application surface, removing the rubber based adhesive foam tape after contact with the application surface may cause damage. Either by failure of the foam (tearing) or failure of the surface (i.e. drywall tearing off with removed foam tape). It is important to always test a small section in a discrete area before full use of any product.
Application Notes: Ensure surfaces are well unified, clean, dry, and free of dirt / oils. Apply firm and even pressure to adhesive-to-surface contact. Allow proper temperature / time to enhance bond strength. It is the end user’s responsibility to determine final suitability of Pres-On’s product for use in their application. For Terms and Conditions: Terms & Conditions – Pres-On (preson.com)