Standard Test Method for Peel Strength ("T" Method) of Hook and Loop Touch Fasteners

SIGNIFICANCE AND USE
This test method gives a measure of a key property of hook and loop touch fasteners which is of interest to users of such devices. This is a means of determining the resistance to separation when forces are applied normal to the line of separation of the fastener.  
The force registered in a peel test is irregular, and as a consequence, empirical methods have had to be developed to obtain usable values related to peel strength. In spite of the empirical nature of the reported values, it is believed they reflect comparative performance of similar touch fasteners tested and measured in the same way.  
Two optional methods of calculation are provided: integrator average and average of five highest peaks. These test methods are not equivalent. Generally, the integrator average will be lower than the average of the five highest peaks.  
The highest peaks which reflect the force required to separate a hook and loop closure bear no simple relationship to the average force (integrator average). The average of the five highest peaks better reflect performance but the integrator results may be used to characterize a closure and for quality control purposes. The integrator average is relatively easy to calculate given the proper equipment.  
In the case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogenous as possible and which are from a lot of hook and loop of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test and an acceptable p...
SCOPE
1.1 This test method covers the measurement of the peel strength of hook and loop touch fasteners using a recording constant-rate-of-extension tensile testing machine (CRE).
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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Publication Date
31-May-2010
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Drafting Committee
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ASTM D5170-98(2010) - Standard Test Method for Peel Strength ("T" Method) of Hook and Loop Touch Fasteners
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D5170 − 98(Reapproved 2010)
Standard Test Method for
Peel Strength (“T” Method) of Hook and Loop Touch
Fasteners
This standard is issued under the fixed designation D5170; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope methods are not equivalent. Generally, the integrator average
will be lower than the average of the five highest peaks.
1.1 This test method covers the measurement of the peel
strength of hook and loop touch fasteners using a recording
3.4 The highest peaks which reflect the force required to
constant-rate-of-extension tensile testing machine (CRE).
separate a hook and loop closure bear no simple relationship to
the average force (integrator average). The average of the five
1.2 The values stated in inch-pound units are to be regarded
highest peaks better reflect performance but the integrator
as standard. The values given in parentheses are mathematical
results may be used to characterize a closure and for quality
conversions to SI units that are provided for information only
control purposes. The integrator average is relatively easy to
and are not considered standard.
calculate given the proper equipment.
1.3 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the 3.5 In the case of a dispute arising from differences in
responsibility of the user of this standard to establish appro- reported test results when using this test method for acceptance
priate safety and health practices and determine the applica- testing of commercial shipments, the purchaser and the sup-
plier should conduct comparative tests to determine if there is
bility of regulatory limitations prior to use.
a statistical bias between their laboratories. Competent statis-
2. Referenced Documents
tical assistance is recommended for the investigation of bias.
As a minimum, the two parties should take a group of test
2.1 ASTM Standards:
specimens which are as homogenous as possible and which are
D618 Practice for Conditioning Plastics for Testing
from a lot of hook and loop of the type in question. The test
3. Significance and Use specimens should then be randomly assigned in equal numbers
to each laboratory for testing.The average results from the two
3.1 This test method gives a measure of a key property of
laboratories should be compared using Student’s t-test and an
hook and loop touch fasteners which is of interest to users of
acceptable probability level chosen by the two parties before
such devices. This is a means of determining the resistance to
the testing began. If a bias is found, either its cause must be
separation when forces are applied normal to the line of
found and corrected or the purchaser and the supplier must
separation of the fastener.
agree to interpret future test results in the light of the known
3.2 The force registered in a peel test is irregular, and as a
bias.
consequence, empirical methods have had to be developed to
obtain usable values related to peel strength. In spite of the
4. Apparatus
empirical nature of the reported values, it is believed they
4.1 Roller—consisting of a smooth steel surface, approxi-
reflect comparative performance of similar touch fasteners
3 1
mately 4 ⁄4 in. (121 mm) in diameter, 2 ⁄4 in. (57 mm) wide,
tested and measured in the same way.
and equipped with a handle, length 4 ⁄8 in. (105 mm), for
3.3 Two optional methods of calculation are provided:
propelling the roller back and forth without adding additional
integrator average and average of five highest peaks.These test
weight to the specimen being rolled (See Fig. 1).The weight of
the roller (including the handle) is 11 6 ⁄4 lbs. (4994 g 6 114
1 g).
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.54 on Subassemblies.
4.2 Testing Machine—A constant rate of extension (CRE)
Current edition approved June 1, 2010. Published September 2010. Originally
tensile tester shall be used. The tester shall have two clamps
approved in 1991. Last previous edition approved in 2004 as D5170 - 98(2004).
DOI: 10.1520/D5170-98R10.
with centers in the same plane, parallel to the direction of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
motion of the stressing clamp, and so aligned that they will
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
hold the specimen ends wholly in the same plane; a means of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. moving the stressing clamp at a uniform rate of 12.0 6 0.5
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5170 − 98 (2010)
6.1.3 Select a sample consisting of four contiguous speci-
mens as described in 8.1.2 and mark them with the appropriate
identification (roll number, lot number, date, and so forth).
There are four possible direction configurations of closure as
shown in Fig. 2. The four specimens of hook and loop selected
will be used to characterize the peel strength of each of the
configurations.
7. Conditioning
7.1 Condition the specimens in an atmosphere for testing of
23 6 2°C (73.4°F 6 3.6°F) and 50 6 5 % relative humidity, as
described in Practice D618, for a period of 24 h or until the
specimens reach moisture equilibrium. Lay specimens flat with
the functional side up so that the conditioning atmosphere has
free access to them.
FIG. 1 Roller for Making Closure of Hook and Loop Touch Fas-
teners Prior to Testing
8. Procedure
8.1 An initial closure is made and separated to raise the
loops that might have been compressed in packaging.
in./min (305 6 13 mm/min), an autographic device for record-
ing the load; and provided with an integrator if the integrator
average is to be used.
4.2.1 The instrument shall be calibrated to an accuracy of
1.0 % of the full scale and the scale range used for the test shall
be such that the main test falls within 20 to 80 % of full range.
5. Sampling
5.1 Select the test samples so as to be as representative of
the unit (a shipment, a lot, and so forth) as possible.
5.2 Lot—A lot shall consist of all the material of the same
type, color and width, made at the same time from the same
materials in no more than a two week period. It shall be
expressed in linear units of 10 000 yards (9144 m).
5.3 SampleRolls—One roll shall be randomly selected from
each linear unit 10 000 yards (9144 m). If the lot does not
contain five units, additional rolls shall be selected from the lot
to give a sample size of five rolls.
5.4 For specification purposes, the material under test must
be mated with material supplied by the manufacturer of the
material being tested.
6. Specimen Preparation
6.1 Hook and loop material for this test shall be in the width
as supplied, not to exceed 1 in. (25.4 mm) in width. For
materials greater than 1 in. (25.4 mm), a 1 in. (25.4 mm)
specimen shall be slit from the center of the sample. If material
less than 1 in. (25.4 mm) wide is tested, test results will not be
directly proportional to those obtained with the 1 in. (25.4 mm)
wide material.
6.1.1 Remove the outer layer of each roll before selecting
the required number of strips, hook and loop, 8 in. 6 ⁄4 in.
(203 6 6 mm) long
...

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