ASTM D4964 Test Fixture

Description

ASTM D4964 – Standard Test Method for Tension and Elongation of Elastic Fabrics (Constant-Rate of- Extension Type Tensile Testing Machine)

 

ASTM D4964 overs the measurement of tension and elongation of wide or narrow elastic fabrics made from natural or man-made elastomers, either alone

or in combination with other textile yarns, when tested with a constant-rate-ofextension (CRE) type tensile testing machine.

NOTE 1—For determination of similar testing using the constant-rateof- load (CRL) type tensile testing machine, refer to Test Method ASTM D1775.

The use of this test method requires the selection of, or mutual agreement upon, loop tension(s) and elongation(s) at which the test results will be determined.

Laundering procedures require mutual agreement on the selection of temperature and number of washing cycles and drying cycles to be used.

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ASTM D4964 / Significance and Use

This test method for testing loop tension and elongation of elastic fabrics is considered satisfactory for acceptance testing of commercial shipments of elastic

fabrics because the test method is used in the trade for acceptance testing

This test method specifies the use of the CRE-type tensile testing machine.

Users of this test method are cautioned that loop tension test data obtained using this method are not comparable to tension test data obtained using Test Method

ASTM D1775 because of the differences in testing machines.

Test Method ASTM D1775 uses a CRL-type tensile testing machine.

The loop tension and extension relationship of an elastic fabric is an important criterion for judging the suitability of the fabric for various end uses, such as:

foundation garments, brassieres, and swimsuits.

Data from loop tension-recovery curves can be compared only if the tension testing machine, rate-of-extension, maximum loading (or extension), and specimen

specifications are comparable.

Since different machine set-ups will cause different results on the same fabric, machine set-ups must always be specified before making a test and be reported

with the test results.

The test for measuring loop tension at specified elongation( s) is used to determine the tension of an elastic fabric when subjected to a specified elongation which is

less than the elongation required to rupture the fabric.

The test prescribes points of measurement on the extending (outgoing) cycle only.

The test for measuring elongation at specified tension(s) is used to determine the elongation of an elastic fabric when subjected to a specified loop tension which is

less than the tension required to rupture the fabric.

The test prescribes points of measurement on the loading (outgoing) cycle only.

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ASTM D4964 / Apparatus

Tensile Testing Machine, CRE-Type, conforming to Specification ASTM D76, equipped with an automatic recording device and cycling controls.

Band Clamps, to hold loop specimen during testing.

The diameter of the anvils will be 13.06 0.25 mm (0.5 6 0.01 in.) or 6.56 0.25 mm (0.25 6 0.01 in.).

The length of the anvil will not be less than 76 mm (3.0 in.).

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ASTM D4964  / Summary of Test Method

ASTM D4964  / Loop Tension at Specified Elongation(s)—A conditioned loop specimen is mounted in a CRE-type tensile testing machine.

The specimen is then extended at a specified rate to a specified loop tension, and returned at a specified rate to zero tension.

The cycle is repeated two more times to give a total ofthree cycles.

During the test, extension-recovery curves may be plotted by an automatic recorder for all or only the third cycle.

The tension at specified percent elongation(s) is calculated from the graph of the third cycle or obtained from the instrument.

ASTM D4964 / Elongation at Specified Loop Tension—A conditioned loop specimen is mounted in a CRE-type tensile testing machine.

The specimen is then loaded at a specified rate to a specified loop tension, and unloaded at a specified rate to zero loop tension.

The cycle is repeated two more times to give a total of three cycles.

During the test, tension-recovery curves may be plotted by an automatic recorder for all or only the third cycle.

The elongation at a specified loop tension is calculated from the graph of the third cycle or obtained from the instrument.

*** Before conducting ASTM D4964 , it is important to read the entire specification. Standards can be obtained from appropriate standard authorities.

 

***PARSROS  offers several types of grips and fixtures which will enable you to perform a variety of tests

  that are accurate and repeatable.