Specialized Grips and Fixtures for Tear, Peel and Puncture Testing

The sixteen grips and fixtures test flexible materials such as adhesive tape, plastic film, non-woven fabric, geotextile, geogrid, waterproof roll, sponge and shoe soles and uppers, as well as construction materials.

On the construction side they test silicone sealant, aluminum-plastic composite panel, ceramic tile adhesive, aluminum thermal barrier profiles, and steel wire and rope, along with the welded joints of steel wire.

The methods are the ones that do not fit a plain pull: peel, tear, puncture and shear. Safety nets are pulled by their open eyes rather than clamped, on a 20 kN grip shaped for the job.

Capacities run from 500 N for tape, film, sponge and waterproof roll up to 100 kN for the wire and rope shear fixture, and most items mount on Ø10 mm pins. Each fits a NextGen universal testing machine, so a laboratory can add these methods to a frame it already runs.

It measures the peel adhesion of adhesive tapes with the peel held at 90°, to GB/T 2792 and ISO 29862, at forces up to 500 N. It is the fixture for tape specifications that call for a 90° peel value.

Peel adhesion is the force needed to peel a tape from a test surface, reported per unit width so tapes of different widths compare directly. The angle changes the number, so holding the peel at 90° throughout the pull keeps results comparable between specimens and between batches.

The fixture sits on a base 520 mm long and 140 mm wide and weighs 3.66 kg (8.1 lbs). Its upper grip stands 92 mm high and its lower grip 106 mm.

The geogrid fixture peels geogrid between two grips, and the climbing drum fixture peels sandwich structures on a drum that rolls as the specimen separates. Both are rated to 1 kN.

The geogrid peeling fixture follows JTG E50, the test code for geosynthetics in highway engineering, and suits quality control and research work on geosynthetics. Its upper grip is 124 mm wide and its lower grip 54 mm, with a grip length of 140 mm.

The NGG103A climbing drum fixture works to GB/T 17748 for the peel resistance of sandwich structures. Because the specimen wraps the rolling drum, the peel angle stays constant while the bond line advances.

Its parts are light, 0.8 kg for the upper grip and 0.3 kg for the lower, which suits small-scale, precise adhesion work.

The choice follows the material, because each puncture fixture is built around its own standard and probe. For plastic film, the NGP502A drives a Ø1 mm probe through a specimen held in a Ø50 mm ring, to GB/T 21302-2007, at up to 500 N.

For non-woven fabric and other textiles, the NGP103A measures bursting strength to GB/T 19976-2005 at up to 1 kN, with interchangeable Ø25 mm and Ø38 mm probes.

For geotextiles, the NGP503A works to GB/T 14800-2010 and ISO 12236, the static puncture or CBR test, at up to 5 kN. It carries Ø50 mm and Ø8 mm plungers with Ø150 mm and Ø50 mm rings, and the Ø50 mm plunger in the Ø150 mm ring is the CBR arrangement.

Name the material and its standard in a request for a quote, and we will recommend the fixture and probe set that suit it.

Waterproof roll is torn in a dedicated tear fixture and shoe parts in a side-action grip, both rated to 500 N. In a tear test the crack runs through the material itself, where in peel it runs along a bond.

The tear fixture works to GB/T 328.18, the nail shank tear method for bitumen waterproofing sheets. Its upper grip weighs 2.1 kg and its lower grip 3.0 kg, and the fixture is 140 mm wide. Tensile tests on the same roll run in our side-action tensile grips, which include wave-profile faces made for roofing membrane.

The side-action grip tears shoe soles and uppers and also runs tension tests on sponge. Its jaw faces are 40 mm wide for shoe uppers and 30 mm wide for sponge specimens, so each sample type gets a face of its own width.

Each side-action grip weighs 1 kg (2.2 lbs) and stands 250 mm high, which keeps the load string light for tear work on soft and elastic materials.

Each material has its own fixture: a 2 kN shear fixture for silicone sealant, a 10 kN shear fixture for aluminum-plastic composite panel and a 10 kN compression shear fixture for ceramic tile adhesive.

The sealant fixture works to JG/T 475-2015 and is rated from -20°C to +80°C, so the sealant can be sheared cold and hot as well as at room temperature.

The panel fixture follows GB/T 17748, the standard for aluminum-plastic composite panels, on specimens up to 100 mm long.

Tile adhesive is tested to JC/T 547-2005. The compression shear fixture puts the bonded joint under compressive load while it shears, with a solid 7 kg (15 lbs) lower grip and a light 0.8 kg upper part. Pull-off tests on adhesive bonds and cement mortar run on our shoulder fixtures.

Two 20 kN fixtures test aluminum alloy thermal barrier profiles to GB/T 28289-2012, one in shear along the profile and one in tension across it.

A thermal barrier profile joins two aluminum sections through an insulating material, and the standard checks that joint in both directions. The longitudinal shear fixture pushes one section along the other, which shows the force the joint carries before it slips, on specimens up to 100 mm long.

The tensile fixture pulls the two sections apart across the joint. Its upper and lower grips are identical, 1.8 kg (4 lbs) each, with a test width of 104 mm.

The shear fixture is the heavier of the two, with a 6.5 kg (14 lbs) lower grip and a 3 kg (6.6 lbs) upper grip.

A 100 kN (22,481 lbf) shear fixture covers steel wire and rope, and a 2 kN grip pulls welded joints in fine steel wire. The shear fixture has the highest rating of the sixteen and takes specimens of Ø4, Ø5, Ø6 and Ø8 mm. A shear test loads the wire across its section instead of along its length.

The shear fixture's lower grip carries most of the mass at 10.63 kg (23 lbs), against 1.69 kg (3.7 lbs) for the upper grip, and the fixture is 150 mm wide.

The NGA203D tests the welded joints in tension to GB/T 33281-2016 and GB/T 26941.3, on wire from Ø0.5 mm to Ø5 mm, and each of its grips weighs 1 kg (2.2 lbs).

Straight tensile tests on the wire or rope itself run in our snubbing grips for wire and cable.