There are several methods used for evaluating the physical parameters of fabrics & garments.

ASTM D751 - GRAB TENSILE STRENGTH

ASTM D751 - BURSTING STRENGTH

ASTM D1117 - TRAPEZOIDAL TEAR

ASTM D2582 - PUNCTURE, PROPAGATION TEAR

ASTM D392 - FLEX TEST

ASTM D2136 - LOW TEMPERATURE BEND TEST

ASTM D4157 - ABRASION RESISTANCE

ASTM E96 - MOISTURE VAPOR TRANSMISSION RATE

ASTM F1358 - FLAME IMPINGEMENT TEST

ASTM D751 - TEST METHOD FOR GRAB TENSILE STRENGTH

"Standard Test Method for Coated Fabrics"

Explanation of Test Method:

The material is cut to specific sample size. The sample is then placed symmetrically between to clamps. The clamps are pulled in opposite directions and the maximum breaking strength of the fabric is recorded.

Grab Tensile Strength Defined:

The maximum force needed to break a material. The breaking strength is measured in lbs-force.

ASTM D751 - TEST METHOD FOR BURSTING STRENGTH

  "Standard Test Method for Coated Fabrics"

Explanation of Test Method:

The test method allows the use of either of two separate procedures. They are called 'Mullen Burst' and 'Ball Burst'. The Mullen Burst test uses a circular material sample that has been clamped over a diaphragm and inflated with oil. Pressure is applied until the fabric bursts. The pressure (in pounds per square inch) at which the fabric bursts is the bursting strength.

The ball burst test uses a steel ball attached to a tensile test machine which forces the ball through a sample of fabric that is clamped rigidly in place. The results are expressed in pounds force.

Bursting Strength Defined: (also Mullen Burst or Ball Burst)

This test is similar to forcing an elbow through a sleeve. It measures the pressure required to burst a fabric. The measure is in units of force per unit area (lb/in² or N/m²). Pressure is applied to the material in one of two ways, either a 'ball' is pushed into the fabric sample or the sample is clamped onto a device and inflated with oil. The force required to burst through is measured.

ASTM D1117 - TRAPEZOIDAL TEAR TEST METHOD

  "Standard Test Method for Trapezoidal Tearing Strength of Geotextiles"

 Explanation of Test Method:

The effort required to continue a tear across a fabric. A slit in the sample is the starting point for the tear. The test specimen is a trapezoid shape.

 Trapezoidal Tear Defined:

The ability to resist a continued tear from an object such as a nail or a bolt. Tear strength is measured in units of force (pounds or Newtons).

ASTM D2582 - PUNCTURE, PROPAGATION TEAR

  "Standard Test Method for Puncture Propagation Tear Resistance of Plastic Film and Thin Sheeting"

Explanation of Test Method:

A weighted dart is dropped onto the sample, the weight is increased until material is punctured and torn a set distance (length).

Puncture, Propagation Tear Defined:

The effort needed to puncture and then tear a fabric when in contact with a sharp object such as a nail or a bolt. Tear strength is measured in units of force (pounds or Newtons).

ASTM D392 - FLEX TEST METHOD

  "Test Method for Flex Durability of Flexible Barrier Materials"

Explanation of Test Method:

Fabric material is flexed repeatedly to determine the subsequent effect on chemical performance. Also used as a conditioning test in NFPA 1991. Film based products perform well in flex tests.

Flexure Resistance Defined:

This test provides a measure of durability related to overall wear.

ASTM D2136 - LOW TEMPERATURE BEND TEST

  "Standard Test Method for Coated Fabrics - Low Temperature Bend Test"

Explanation of Test Method:

This test subjects the material to a pre-designated low temperature and flexes the material at that temperature. The test sample is then visually examined for signs of cracking or other damage.

Low Temperature Bend Test Defined:

This test measures the ability of the fabric to perform in cold temperatures.

ASTM D4157 ABRASION TEST METHOD

  "Test Method for Abrasion Resistance of Textile Fabrics - Oscillator Cylinder Method"

Explanation of Test Method:

The material is abraded a set number of times on a rough surface to determine the effects on subsequent chemical performance.

Abrasion Resistance Defined:

This test provides a measure of durability related to overall wear. It is used as a conditioning test for NFPA 1991 chemical battery.

ASTM E96 - MOISTURE VAPOR TRANSMISSION TEST METHOD

  "Standard Test Method for Water Vapor Transmission of Materials"

Explanation of Test Method:

This test method measures the ability of a fabric to allow moisture vapor to pass through. There are four different procedures within this test method. The different procedures vary the temperature and humidity of the test environment. The results are presented as the weight of water in grams that pass through one square meter of fabric in a 24-hour period. (g/m²/24hr).

NOTE: When comparing test results between products, be certain that the same procedure has been used.

MVTR - Moisture Vapor Transmission Defined:

A 'comfort test', describes the rate of evaporation of moisture through a fabric. It is expressed in grams per square meter per 24 hours. Used to measure the ability of a fabric to allow the dissipation or transfer of moisture vapor that results from human perspiration. The body cools itself by evaporative cooling or sweating.

(NOTE: Air Porosity describes the ability of a fabric to allow air to pass through it. Any fabric that allows air to pass through cannot be considered a good liquid barrier. However, certain fabrics like the microporous film composites will allow moisture vapor transmission, without air passage, and can still be considered basically good liquid barriers.)

ASTM F1358 - FLAME IMPINGEMENT TEST METHOD

  "Effects of Flame Impingement on Materials Used in Protective Clothing not Designated Primarily for Flame Resistance"

Explanation of Test Method:

A material sample is folded and placed in a vertical position inside a test chamber. A burning methane gas flame is placed in contact with the folded edge of the material.

There are other requirements in the test, such as the size of the fabric swatch, etc. A copy of the actual test method is available from DuPont on request.

 Flame Impingement Test Defined:

A test designed to determine the flammability of a fabric designed for uses outside of flame protection.

There are several different companies that provide information and sell copies of standards and test methods. One of these companies is ILI Infodisk Inc. ILI can be reached in the United States at: