The Importance of Elongation at Break in Pressure Sensitive Adhesive Tapes
Pressure sensitive adhesive tapes (PSA tapes) are subjected to a wide range of forces no matter what type of application they are used in. That’s why bonding specialists and engineers place such a heavy emphasis on the mechanical properties of PSA tapes. When focusing on single sided PSA tapes, elongation at break is one of these critical properties. What makes a single sided PSA tape’s elongation properties important to its performance? Find out more about how this mechanical property can make or break a piece of PSA tape in your application.
What is Elongation in PSA Tapes?
Elongation break percentage shows how far the material can be stretched (as a percentage of its original dimensions) before it breaks. Often used as a measure of solid rubber and elastomeric foams, elongation break is also a common measure used for single-sided tapes. It’s a measurement that will show how much the material will deform up until it fractures, which helps provide a numerical value that differentiates tape backings. In terms of PSA tape, it is the distance a tape will stretch before breaking under controlled conditions, which is tested with ASTM D412.
Also known as percent elongation or fracture strain, elongation at break is typically expressed as a percentage of the original length of the tape. A higher elongation at break percentage indicates that the material will resist fracturing when stretched.
The Importance Understanding of Elongation in PSA Tapes
Elongation is one of many mechanical properties that are important to understand about your PSA tapes to ensure you’ve the right material for the application. When PSA tape backing has a higher elongation,
More conformable: allowing them to bend and contour to the shape of a substrate. 3M™ Extreme Sealing Tapes are a terrific example of a highly conformable tape designed to seal uneven surfaces with over 400% elongation at break.
More elastic: this makes them more Puncture and tear resistant. On of the most conformable tapes, 3M Sealing Tape 8777, is specially formulated to with a propriety backing and cold weather adhesive designed to be used as a flexible waterproof membrane in building sealing. Its elongation at break is over 700%, compared to the very conformable vinyl tapes used for floor marking (like 3M Vinyl Tape 471 which has an elongation at break of 130%). Learn more about the elongation of various single-sided tape backings here.
The Difference Between Elongation at Break Percentage and Backing Tensile Strength
It may seem like elongation at break is the same as backing tensile strength, which is the ability of a material to resist pulling stress before breaking, but the two mechanical properties measure slightly different things. Both measure how far a piece of tape can stretch without breaking, but elongation is measured as a percentage, while tensile strength is measured in terms of a force: (i.e., Pascals or Megapascals, which is equivalent to Newtons per square meter (N/m²). Tensile strength will tell you how much of a force can be applied to the material before it breaks, elongation at break will tell you what percentage the material can be stretched before it breaks.
Find the Right PSA Tape for Your Application
Understanding elongation at break allows engineers and bonding specialists to choose the best tape for their specific application. A higher elongation at break gives a PSA tape the flexibility it needs to adapt to irregular surfaces, resist tearing. If you need to know if a specific PSA tape can withstand the expected forces in your application, our bonding specialists can you find the answer.
Get in touch with our team today to talk about your bonding challenges.