OPP Tape Tensile Test — For Breaking Strength and Elongation at Break
An OPP tape tensile test measures how much force a strip withstands and how far it stretches before rupture. In this YG Group demonstration, a technician cuts OPP tape from a roll, mounts it between grips, and pulls it to failure. The test helps packaging teams understand how the tape backing behaves under tension.
Quick answer — Pull a straight strip of tape between two grips at a controlled rate. Use the force at rupture and the strip width to determine breaking strength. Use the extension at rupture and the starting distance between the grips to determine elongation at break.
How Does an OPP Tape Tensile Test Work?
The testing machine grips both ends of the tape. One grip moves away from the other at a set speed. As the distance increases, the tape stretches and the machine tracks the force. The test ends when the strip breaks. The video references ISO 29864:2018 Method A for self-adhesive tapes without filament reinforcement. For this method, the machine holds a flat strip in two aligned grips.
What does breaking strength measure?
Breaking strength expresses the force at rupture per unit of tape width. It describes how much pulling force the tape can withstand under the chosen test conditions. On a finished tape data sheet, you may see this property under the heading “tensile strength.”
Width matters because a wider strip of the same tape generally requires more force to break. Therefore, check both the unit and the specimen width when comparing specifications. ISO expresses tape breaking strength in newtons per 10 mm of width.
What does elongation at break measure?
Elongation at break describes the increase in length at rupture as a percentage of the starting gauge length. The starting gauge length is the open span between the grips when the test begins. The full cut strip also includes the ends inside the grips.
Because the calculation uses the starting span, record that distance during setup. Then use the increase in grip separation at rupture to determine how far the specimen stretched. Both measurements describe the same pull from different angles. One describes force, while the other describes stretch.
Watch the YG Group Lab Demonstration
YG Group laboratory demonstration · 1 min 37 sec in total
The video shows four stages. First, the technician takes tape from the roll and checks the edges of the cut strip. Next, the technician centers the strip between the upper and lower grips. The machine then pulls the tape until it ruptures. Finally, the video explains how to identify the break location and when to run a replacement specimen.
| Approximate time | What to look for |
|---|---|
| 0:25–0:36 | Laboratory conditions, strip length, specimen count, and rest time |
| 0:38–0:50 | Removal of the outer wraps and preparation of the tape strip |
| 0:51–0:59 | Vertical mounting, alignment, and grip handling |
| 1:00–1:09 | Calibration check and the pull to rupture |
| 1:10–1:19 | How the method handles a break close to a grip |
Equipment and Specimen Preparation
Have the tape roll, a clean cutting surface, a suitable cutter, and a ruler ready. The test also needs a constant-rate tensile machine with two suitable grips. Before cutting, identify the roll and note which direction you intend to test.
| Preparation detail | Test Condition Setup |
|---|---|
| Room temperature | 23 °C ± 1 °C |
| Relative humidity | 50% ± 5% |
| Specimens per roll | 5 |
| Total strip length | 200 mm |
| Specimen rest time | 16 hours |
The table describes the setup in this video. For a formal test, use the exact standard and edition that your lab or customer specifies. Follow its requirements for specimen dimensions, conditioning, grip separation, and machine speed.
Sample the roll and inspect the cut edges
First, remove the outer three to six wraps, as shown in the video. Then cut strips to the required dimensions and check both edges under good light. Handle each strip gently so it stays flat and free of creases.
Edge condition matters because a small nick can become the point where a tear starts. Also, a fresh lab cut can behave differently from an edge slit at the factory. Record which edge type you tested, especially when comparing rolls from different sources.
Specimen preparation in the YG Group lab demonstration, approximately 0:49
Mount the Strip and Pull It to Rupture
- Align the strip. First, secure one end in the upper grip. Then place the lower end in the other grip. Center the strip in both jaws and keep its long axis in line with the pull.
- Set the starting span. Keep the strip straight and avoid stretching it by hand. Next, record the initial distance between the grips. Check that both ends sit securely in the jaws before starting the run.
- Start the pull. Confirm the machine’s calibration status and use the speed required by the selected method. Then start the machine and let it pull the tape to rupture. Keep hands clear of the strip and grips during the run.
- Inspect the break location. After rupture, check where the tape separated. If the break occurs within 5 mm of a grip, apply the method’s validity rule. Test a replacement when the method calls for one.
Specimen alignment in the YG Group lab demonstration, approximately 0:57
Why do centering and grip pressure matter?
If the strip sits at an angle, one edge can take more of the load. Consequently, the tape may start to tear on one side. Sight along the strip before the pull to check that it runs straight between the grips.
Similarly, slippage can add to the apparent extension because some grip movement comes from the tape sliding. Check that both ends hold firmly and look for signs of movement after the run. If a break occurs close to a jaw, record its location and follow the selected method’s rule.
What the Test Tells You About Packaging Tape
For BOPP packing tape, a lengthwise pull helps show how the tape behaves under tension during dispensing and application. However, a carton seal also depends on how the adhesive bonds to the board. Check the tape on the actual carton material if you need to evaluate the complete seal. YG Group’s guide to choosing packing tape
Peel adhesion answers a separate question. It measures the force needed to peel applied tape from a defined surface. So, if tape lifts from a carton while the backing stays intact, review adhesion and application conditions as part of the investigation. YG Group’s peel adhesion test guide
What should two labs match before comparing tape?
Start with the same test method and edition. Then check the direction of pull, the specimen width, and whether each lab used factory edges or fresh cuts. Also confirm that both labs used the same starting grip separation, speed, and conditioning. Matching these details helps you trace a difference to the tape or the setup.
For example, two strips can come from the same roll but have different edge conditions after cutting. Likewise, a lengthwise strip and a crosswise strip can respond differently to a pull. Record these choices when you prepare the sample so someone else can repeat the setup.
Frequently Asked Questions
① Do I need a separate test for elongation at break?
Both measurements come from the same pull. The machine tracks force and grip movement as the strip stretches. At rupture, the force and extension provide the inputs for the two properties.
② Why does the video use a longer strip than the span between the grips?
Each jaw needs enough tape to hold the specimen securely. Therefore, part of the strip sits inside the grips. The gauge length covers only the free span between the jaws at the start of the pull.
③ Can I use a backing film data sheet to evaluate finished tape?
A film data sheet describes the backing before it becomes part of the finished tape. A test on the coated strip includes the construction and edges that the operator handles. So, for a purchasing decision, ask which material the supplier actually tested.
Also check how the supplier reports the property. Film specifications may express tensile stress per unit of cross-sectional area. In contrast, the ISO tape result uses force per unit of width. Those units describe different measurements.
④ Is there an ASTM method for pressure-sensitive tape?
ASTM D3759/D3759M covers breaking strength and elongation for pressure-sensitive tapes. If a purchase specification names ASTM or ISO, use the specified method and edition. Then keep that reference with the tape identification and test setup. ASTM D3759/D3759M
Discuss a Carton Sealing Tape Application
If you are selecting a carton sealing tape for a new packing line, start with the board type, tape width, and application method. Also tell YG Group which standard your quality team uses. These details help the team identify the relevant product information for your application. Contact YG Group about packing tape
