We tested the adhesive strength of six varieties of adhesive bandages with the TA.XT2 Texture Analyzer using a TA-220 Multiple Puncture Fixture with a TA-53 5 mm diameter punch probe.  The bandages tested were 3M's Active Strip Brights Flexible Foam, Curad's Sheer Strips, Sensitive Skin, Neon Strips Flexible Fabric, Payless' Clear Bandages, and Tsumura Int'l's Kid Care Printed Adhesive Batman Bandages.  All bandages were store-bought.

The adhesive sides of each of the bandages were trimmed from the bandages' pad sections, and placed adhesive side facing upwards across the bottom of the TA-220 Multiple Puncture Fixture's openings.  These adhesive sections of the bandages were firmly, but not too taut, placed across the openings.  The TA-52 puncture probe was consistently positioned approximately 3 mm over the adhesive bandages within the fixture's openings.

During the test the probe traveled until it the surface detection feature detected the bandage at 10 grams of force, at which point it applied 150 grams of force onto the adhesive bandages at a speed of 2.0 mm/second for a period of 10 seconds.  The probe withdrew 10 mm at 5.0 mm/second.

This application study is designed to illustrate the capabilities of the TA.XT2 Texture Analyzer in peel tests on masking tapes.

The fixture we used was the TA-305 Peel Test Rig. The TA-305 (illustrated below) has a free flowing stainless steel wheel with a polished surface.  The wheel is 3/4" (19.05 mm) wide and has a radius of 50.8 mm and a diameter of 319.2 mm.  The wheel is mounted on a ball bearing to ensure a resistance-free roll.  The  upper end of the tape is held with a TA-96T adjustable grip, with a 3/4" deep and 1 1/4" wide face.

The tapes were unwound directly onto the wheel from the rolls using a light amount of tension, and ensuring that the tape was evenly applied.  In the event the tape deviated from an even application, the entire tape was re-applied after the wheel was wiped cleaned with a paper towel damp with alcohol cleaner and then wiped dry with a second paper towel (cleaning also applied between tests).  The last 1/2" of tape was folded over itself and placed into the TA-96T grip and the grip was fastened finger tight.  Apparent slack in the tape was taken up by raising the cross arm slightly.

Test Protocol. The grip traveled upward at 1.0 mm/second until any remaining slack was taken up until 12 grams of force was detected.  At that point the grip traveled upward for 120 mm at a speed of 3.0 mm/second.  The grip returned to its starting point at a rate of 10.0 mm/second. Data was collected at 25 points per second (the Texture Expert software can collect data as slowly as 0.10 points per second to as fast as 500 pps).

The brands of masking tapes tested were: 3M's Scotch brand Professional Grade Painter's Masking Tape, 3M's Scotch brand Long Mask Blue Masking Tape, 3M's Scotch brand Drafting, and Ace Hardware's Masking Tape.  All tapes were purchased at a local office supply store.  Two complete rotations of tape were removed from each roll to avoid any "end of roll" effect.

Calculations for Adhesive Tape Style Products. The following graph illustrates a few of the calculations appropriate for peel tests.  The illustrated parameters, however, are not exclusive, and individual manufacturers may be interested in their own parameters.  Virtually any custom calculation can be accomplished with either the Windows or DOS software, and the information can be presented in Force vs Distance (as shown) or Force vs Time formats.

We calculated: item (1) above by using the mean force between -20 m to -100 mm of peel travel, item (2) above by integrating the area under the graph for the same travel range, and item (3) above by counting the number of peaks using force thresholds of 15 grams, 25 grams, and 50 grams. The number of peaks is an indication of the magnitude of jaggedness. All calculations were made on the individual test replicates, although the graphs presented below are each the average of six test replicates.

Application Study Conclusions
These peel tests provided very repeatable differentiation between the masking tapes, including the adhesive strength of the tapes (as measured by average forces and integrated areas of work) and the evenness or unevenness of the adhesive pull.  The test results' coefficient of variations (standard deviation divided by the mean) are low relative to adhesive tests on individual locations of a tape (refer to Study I-3W on pressure sensitive tapes). The decreased variability is consistent with this test's design which measures the tape's average adhesive behavior over a particular length.

The ACE Hardware masking tape was the most adhesive masking tape based on all of the above parameters. The ACE Hardware product also had the most jagged curve, indicating that its' adhesive material is irregularly distributed across the tape or that the tape's backing was more variable than the others'. The 3M Drafting was the least adhesive by all measures and its adhesive material appeared to be more consistently distributed or the backing was very consistent. The 3M Drafting tape was likely designed for adherence to paper products, so its' low relative adhesiveness is not unexpected. The 3M Professional Grade and the 3M Long Mask Blue tapes exhibited many similarities with each other, with the 3M Professional Grade tape being marginally more adhesive.

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The tests presented in this study indicate that the TA.XT2 Texture Analyzer, along with the Texture Expert for Windows  Software, can used to quantify the peel strengths of adhesive tapes (and similar products) in a manner which can provide excellent differentiation between products.

The TA.XT2 Texture Analyzer can be used in research & development, production, or quality control applications for the adhesives and related industries.