Rubber Coated Fabric

ASTM D751 is used to ensure the quality of rubber-coated fabrics including tarpaulins, rainwear, outdoor clothing, and similar products. ASTM D751 features multiple mechanical properties tests for coated fabrics such as tarps, outdoor clothing, and rain wear.

Tests include breaking strength by Procedure A: Grab Test and Procedure B: Cut Strip Test, Elongation, Burst strength, puncture resistance, tear strength (tongue tear), trapezoidal tear, Adhesion coating to fabric, tack tear resistance, seam strength, dead load seam strength, and crush resistance. A TestResources universal test machine can be used for all the tests in ASTM D751. Our test engineers are experienced with testing to ASTM D751 and can help guide you through the testing process. We recommend that you purchase the official ASTM standard to achieve the best results.

D751 Breaking Strength

This test determines the breaking strength of the coated fabric by either the Grab Test Method (Procedure A) or the Cut Strip Test Method (Procedure B).

Preparing the Specimens

Gather two sets of 5 specimens each for longitudinal and transverse breaking strength.

  • Procedure A: 100 mm wide X 150 mm long cut from coated fabric
  • Procedure B: 25 mm wide X 150 mm long cut from coated fabric

Test Procedure

  • First, place the specimen symmetrically in the fixture clamps with the longer dimension parallel to the direction of the applied force.
  • Start the tension test at a rate of 5 mm/second.
  • Record the maximum force required by the universal test machine to break the specimen

Accessories Required for Breaking Strength

D751 Elongation

This test determines the elongation of the coated fabric during the breaking strength tests. This test should be performed at the same time as breaking strength with the same specimens.

Preparing the Specimens

Use the same specimens as for breaking strength. Procedure A is the preferred method to test, but Procedure B is also acceptable.

  • Procedure A: 100 mm wide X 150 mm long cut from coated fabric
  • Procedure B: 25 mm wide X 150 mm long cut from coated fabric

Test Procedure

  • First, place the specimen symmetrically in the fixture clamps with the longer dimension parallel to the direction of the applied force.
  • Start the elongation test at any stated force when the breaking strength is determined. This will be recorded by the UTM controller.
  • Record the maximum force required by the universal test machine to break the specimen

Accessories Required for Elongation

D751 Bursting Strength

The bursting strength test determines the bursting strength of the coated fabric. This test is characterized by a spherical plunger fixture.

Preparing the Specimens

Ten specimens should be cut with the smallest dimension at least 12.5 mm greater than the outside diameter of the ring-clamp.

Test Procedure

  • First, mount the test specimen in the ring clamp.
  • Start the universal test machine at a rate of 5 mm/second until a rupture occurs.
  • Record the force maximum force as the bursting strength of the specimen.

Accessories Required for Bursting Strength

G174 Burst Test Fixture with 25 mm spherical plunger and a 44 mm internal diameter ring clamp.

D751 Puncture Resistance

This test determines the puncture resistance of the coated fabric. This test is different than the bursting strength test in that you operate the test machine at a faster rate and use a sharp plunger shaped fixture to puncture the fabric.

Preparing the Specimens

Five specimens should be cut with the smallest dimension at least 12.5 mm greater than the outside diameter of the ring-clamp.

Test Procedure

  • First you should mount the test specimen in the ring clamp.
  • Start the universal test machine at a rate of 300 mm/min until a puncture occurs
  • Record the maximum force recorded by the test machine as the puncture resistance of the specimen.

Accessories Required for Puncture Resistance

G174 Burst Test Fixture with a sharp plunger and a 44 mm internal diameter ring clamp.

D751 Tearing Strength

Tearing strength can be determined by two methods: Pendulum Test Method and the Tongue Tear Method. The falling pendulum method (also called the Elmendorf method) requires a special 405 Family Elmendorf Impact Resistance Test Machine. The Pendulum Test Method requires the specimen to be held between two clamps, one movable and one stationary. The specimen is then torn by the fall of a pendulum through the force of gravity. The other method, the Tongue Tear Method is more common and requires a universal testing machine.

Preparing the Specimens for the Tongue Tear Method

Five specimens from each of the warp and filling directions should be tested. Specimens should be rectangular in shape and 75mm X 200 mm in size. Make a 75 mm cut at the center of and perpendicular to a short side of the specimen to form the tongues.

Test Procedure

  • First center the specimen in the machine with one tongue fastened in each clamp
  • Start the machine with a uniform speed of .85 mm/second
  • Record the force necessary to tear the cloth a distance of 75-100 mm
  • Tearing Strength shall be the average of the 5 highest peak loads during the tearing.

Accessories Required for Tearing Strength

For the tearing strength test use the TestResources G240G Vice Grips for up to 5 kN force and our GD751-240k Specialized Vice Grips for ASTM D751 for up to 1 kN force.

D751 Adhesion of Coating to Fabric

This test determines the adhesion of coating of the coated fabric.

Preparing the Specimens

The adhesion of coating to fabric test in ASTM D751 requires two sets of two specimens each for the longitudinal and transverse direction. Your specimens should be rectangular and sized as 25mm W X 200 mm L. After creating the specimens, separate the coating from the backing for a distance of 50 mm.

Testing Procedure

  • First clamp the separated portions of your sample in the jaws so that movement of the test machine will separate the coating from the backing.
  • Next run the test machine so that it separates the coating from the backing with a uniform speed of .85 mm/s or 5 mm/s for a minimum of 76 mm.
  • Record the force necessary to separate the coating from the backing.
  • Adhesion of coating shall be the average of the 5 highest peak loads during the test.

Accessories Required for Adhesion of Coating to Fabric Test

For this test, use our G240G Vice Grips for up to 5 kN force. You may also use our GD751-240k Specialized Vice Grips for ASTM D751 for up to 1 kN force.

D751 Tack-Tear Resistance

This test determines the tack-tear resistance of the coated fabric. This test requires a specialized fixture as shown in Figure 4 of the official ASTM D751 standard.

Preparing the Specimens

Create two sets of five specimens each for warp and filling tack-tear strength. The specimens should be rectangles and 50mm W X 150 mm L in size.

Testing Procedure

  • Clamp the specialized fixture device in the upper clamp of the test machine and adjust the machine to compensate for its weight.
  • Next impinge the specimen on the needles.
  • Clamp the specimen in the lower clamp.
  • Run a tension test a 5mm/second.
  • Finally record the average force necessary to tear the fabric

Accessories Required for Tack-Tear Resistance

You will need a specialized tack-tear resistance fixture shown in Figure 4 of the standard official standard. Call our fixture engineers today and they can provide you with a specialized fixture just for this test.

D751 Seam Strength

This test is used to determine compare the seam strength with the strength of the coated fabric. The seam strength test works great for lapped, lapped and bonded, and sewn seams using the modified grab test method.

Preparing the Specimens

You will need to create three specimens for the seam strength test in ASTM D751. Specimens should be in rectangle shapes and should be 50mm W X 200 mm L with the seam horizontally across the center.

Testing Procedure

  • First place the specimen symmetrically in the jaws of the grips with the seam centered between the jaws.
  • Start the test machine with a uniform speed of 5 mm/second.
  • Record the force necessary for the sample to slip the seam or rupture the fabric.
  • Seam Strength shall be the median of all the individual results.

Accessories Required for the Seam Strength Test

Use our G240G Vice Grips for up to 5 kN force. You may also use the TestResources GD751-240k specialized for ASTM D751 grab tests.

D751 Crush Resistance

This test in ASTM D751 determines the crush resistance test of coated fabric. This test is applicable to diaphragm material cut from coated fabrics that will be used for automotive and regulator devices.

Preparing the Specimens

Three specimens should be tested. Specimens should be rectangles sized 50 mm wide X 200 mm long.

Testing Procedure

  • First you must place the specimen symmetrically on the base plate of your compression tester or universal testing machine.
  • Place the load button on the test specimen with the recessed end down and at least 12 mm from any edge of the specimen.
  • Apply the force to the button with a uniform speed of .83 mm/second until a deflection is noted by the test machine.
  • Record the force required to crush or cut the specimen.

Accessories Required for Crush Resistance Test

For this test you will need a Crush Test Fixture as noted in the standard. You may also use the TestResources GD751-240k specialized for ASTM D751.

Equipment Required for ASTM D751

Due to the wide variety of test procedure in ASTM D751, our test engineers recommend you purchase a universal test machine. TestResources UTM’s can be configured to operate an array of tests by simply exchanging the fixture attached to the machine. Our top universal test machine recommendations are:

If you will be performing the tearing strength test by Pendulum Test Method (also called the Elmendorf method), this test requires a special 405 Family Elmendorf Impact Resistance Test Machine. You can pair these universal tester with our XyLive Software needed for adhesion and tear tests in this standard. XyLive Software allows you to watch the data live as the test runs.

Grips and Accessories Recommendations

Call our engineers today for help testing to ASTM D751 and for help choosing the best test equipment.

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