What to know about calculating yield strength and tensile strength of pressure-sensitive tapes

(BPT) - Material selection for your custom adhesive converter should never be left to chance. One factor in choosing a pressure-sensitive adhesive is tensile strength. Tensile strength is of particular concern in uses where the bond must stand up to repeated stress and tension, such as packaging, strapping, palletizing, connecting joints and mechanical parts.

What is tensile strength?

Tensile strength is a calculation that measures the maximum force and stress the material can take before breaking. (Note: This refers to the breaking apart of the tape, not a clean break of the bond.) When using pressure-sensitive adhesives to bond two materials, tensile strength can indicate whether the tape is strong enough to hold its original shape when exposed to stress during normal usage.

When is high tensile strength tape needed?

Choosing the right pressure-sensitive adhesive requires technical expertise of the adhesive as well as the carrier. It’s important to understand that tensile strength measurement refers more to the strength and durability of the carrier, less so to the adhesive.

The tape’s carrier has a large impact on the performance of high tensile strength tape. In addition to tensile strength, other factors of the carrier you might consider include resistance to moisture and abrasion, and its ability to insulate against or conduct electrical currents.

If your application requires a bond that can stand up to the forces of movement and stress, bonding strength of high tensile tape is just part of the equation. The carrier of high tensile tape provides the structure and strength to keep and hold the bonded materials. In certain applications, particularly in packaging, industrial, automotive and aerospace, the overall strength carrier material can help you determine the high tensile tape's performance and durability.

How to calculate tensile strength

To help you identify the right high tensile strength tape that won’t break and fail when exposed to weight and stress, calculating the tensile strength needed for your application can help narrow your search for the right adhesive tape materials.

Typically, tensile strength is measured in pounds per inch of width, but it’s also calculated in millimeters. Before you run the formula, you’ll need to obtain a couple of measurements.

  • First, measure the Newton units, the maximum force the adhesive bond would be subject to. The formula for Newton units is 1 kg⋅m/s2.
  • Next, measure the area where the material would be bonded, whether it’s millimeters or inches.

Calculate tensile strength by dividing the load by the bonding area: N/A = tensile strength your adhesive tape requires. (Ideally, you’d select an adhesive that exceeds this figure.)

Yield point of adhesive tape

Another characteristic of the high tensile tape is its yield point, because it too can make all the difference between performance and failure of your end product.

The yield point is the maximum stretching point of the high tensile tape that allows it to return to its original shape. This elongation point will always be reached before maximum tensile strength. It can be useful to know the exact parameters of the high tensile tape, so you can set the limits for weight and force and easily recognize when a bond is reaching the point of failure.

Elongation is expressed as a percentage, showing the increase/decrease of the tape’s dimensions after application of stress.

Evans EVCO is here to help

That’s where Evans EVCO can help you get more done in less time. We have decades of experience with adhesives and tapes, along with our preferred partnership with 3M. This gives us the technical expertise and tools to quickly identify the pressure-sensitive tape with the properties that meet your requirements. Our goal is to help you identify best-performing material at the most efficient pricing. Your pressure-sensitive tape can also be die cut to a custom shape or size.

Ready to talk about your product? Schedule a consultation with your helpful Evans EVCO representative today.