ASTM D5170 T Peel Strength of Hook and Loop Touch Velcro Fasteners

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ASTM D5170 T Peel Strength of Hook and Loop Touch Velcro Fasteners

ASTM D5170 is a standard test method to measure peel strength of hook and loop fastners (often times referred to as Velcro). This test measures the strength of the fasteners for production control, vendor-customer specifications and incoming raw material lot qualifications. Our engineers are familiar with the ASTM D5170 test procedure and can guide you through the process and help you choose the best equipment. We also recommend that you purchase the ASTM D5170 standard and follow it closely to achieve the best results.

Preparing the Specimens

In order to achieve the best results for ASTM D5170, condition your hook and loop faster samples for 24 hours at room temperature and 50% humidity. Your specimens should be 1 inch wide and 8 inches long. If the product you are testing is wider, then cut 1 inch wide strips from the middle using a TestResources Sample Cutter to minimize disruption of the hooks and loops in the product.

The hooks and loops in the material have different orientations, but the hook and loop connection is created to connect reliably regardless of the orientation. Although it is expected to hold regardless, hook and loop orientation is tested in ASTM D5170. The tests consists of four identical tests, each with a different hook and loop orientation.

Create four specimens, each with a different alignment of hooks and loops. Create two samples of the hooks and loops going in the same direction and two going in the opposite direction (see Figure 4 in official standard). Label each specimen with the type of alignment for later reference.

Creating uniform pressure to stick the specimens together is an important step for ASTM D5170. Make sure to stick your specimens together using a steel plate as a weight. Place the two halves of the hook and loop fastener sheets together and place the steel plate (which should be 8 inches long and 1.5 inches wide) on top of the samples. The plate will weigh 4 pounds, so you do not need to press down, just place the plate on top of the specimens for 2 seconds and remove. Now use a TestResources 4.75 inch weighted sample roller and roll over the samples 5 times back and forth. You do not need to press down, allow the roller to do the work for you. Now you are ready to begin testing.

ASTM D5170 Test Procedure

  1. Set grips 1 inch apart in the Peel Tester
  2. Clamp the hook side sample in one grip and the loop end sample in the other grip so that the samples make a “T” shaped formation. Make sure to center the sample so the peel line is perpendicular to the load line of the Peel Tester.
  3. Run the Peel Test Machine at 12 inches/minute.
  4. Record the force and displacement

Advice from Our Engineers

ASTM D5170 indicates your choice of two different force calculations: average of top 5 max force peaks, or average of all force data point over the peel plot. TestResources XY test software can do this for you automatically. Without our software, you would have to identify the data visually or write a macro in Excel, therefore we recommend using our software as an easier alternative.

ASTM D5170 Recommended Test Equipment

A 100 Series Peel Tester is recommended for ASTM D5170. The 100-250 consists of a vertical load frame, an electromechanical actuator, load cell, a tocuhpad test controller, test software and peel grips. For ASTM D5170, we would configure a small capacity load cell (10 or 25 pound) for this low force peel test. Our load cells measure loads accurately (+/- 0.5% of reading) from full scale rating to 1% of FS. A 10 lb load cell can be calibrated to measure 0.1 lb (0.5N) accurately.

The peel plot will be an important aspect of data retrieval and therefore we highly recommend our software. If you would rather see the data in real-time and study the peel interface at the same time, we would provide you with our XyLive Software.

Peel Grips and Accessories

ASTM D5170 requires vice grips to hold the sample in place. We can provide you with our G227 or G240k Mechanical Vice Grips for simple and effective testing. For faster testing results we offer our G229 Pneumatic Grips. These types pneumatic grips are also helpful in getting the specimen well-aligned in the grips due to the foot activator giving you both hands free to hold the specimen. It is not easy to hold the specimen exactly perpendicular in the grips while you are cranking a manual vice grip.

Give one of our engineers a call today and they can help guide you through the ASTM D5170 test process with the best machine configuration for your requirements.