ASTM F2749-09
(Test Method)Standard Test Method for Determining the Effects of Creasing a Membrane Switch or Assembly
Standard Test Method for Determining the Effects of Creasing a Membrane Switch or Assembly
SIGNIFICANCE AND USE
Creasing of membrane switches or their components can affect their visual appearance, mechanical integrity or electrical functionality. This practice simulates conditions that may be seen during manufacture, installation or use.
Crease testing may be destructive, therefore any samples tested should be considered unfit for future use.
Specific areas of testing include, but are not limited to:
Membrane switch flex tails, and
Any component of a membrane switch that may be subjected to creasing.
SCOPE
1.1 This test method establishes a method for the creasing of any part of a membrane switch with conductive circuits.
1.1.1 The values given in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.2 This standard does not purport to address all of the safety concerns, 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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Designation: F2749 − 09
StandardTest Method for
Determining the Effects of Creasing a Membrane Switch or
1
Assembly
This standard is issued under the fixed designation F2749; 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 3.3 Specific areas of testing include, but are not limited to:
3.3.1 Membrane switch flex tails, and
1.1 Thistestmethodestablishesamethodforthecreasingof
3.3.2 Any component of a membrane switch that may be
any part of a membrane switch with conductive circuits.
subjected to creasing.
1.1.1 The values given in SI units are to be regarded as the
standard. The values given in parentheses are for information
4. Interferences
only.
1.2 This standard does not purport to address all of the 4.1 The following parameters may affect the results of this
safety concerns, if any, associated with its use. It is the test:
responsibility of the user of this standard to establish appro-
4.1.1 temperature,
priate safety and health practices and determine the applica-
4.1.2 humidity, and
bility of regulatory limitations prior to use.
4.1.3 orientation of the conductor (either extension or com-
pression) could have significant impact on the results.
2. Terminology
4.1.4 Inelasticity and parallelism of roller and test bed will
2.1 Definitions:
affect the displacement of the force across the sample. In other
2.1.1 crease—a ridge or groove made by folding and press-
words, the roller and test bed must not be compressible or
ing.
subject to warping or distortion during the test cycle.
2.1.1.1 Discussion—The fold mark in the substrate will be
Furthermore, the roller must remain parallel to the test bed
caused by a roller rolled over a fold that will likely remain in
through the entire test cycle.
the substrate after testing.
NOTE 1—Experience has shown that some conductors recover their
2.1.2 crease cycle—a 180 degree crease followed by a
conductive properties if allowed to stabilize after the dynamic portion of
straightening of the crease (see Fig. 1). the test. Therefore, continuous monitoring is necessary.
2.1.3 membrane switch—a momentary switching device in
5. Apparatus
which at least one contact is on, or made of, a flexible
substrate.
5.1 Roller, allowed to rotate smoothly around its longitudi-
nal axis, rigid, low friction smooth surface.
2.1.4 membrane switch tail—a flexible portion of a mem-
brane switch used for input/output connection. 5.1.1 Roller, measuring 50.8 mm (2 in.) in diameter, toler-
ance 65%.
3. Significance and Use
5.2 Fixture to hold test sample securely in place in a
3.1 Creasingofmembraneswitchesortheircomponentscan
horizontal manner (refer to Fig. 1).
affecttheirvisualappearance,mechanicalintegrityorelectrical
5.3 Mechanisms capable of providing a constant force and
functionality. This practice simulates conditions that may be
rate of travel to roller.
seen during manufacture, installation or use.
5.4 Equipment for the continuous monitoring and recording
3.2 Crease testing may be destructive, therefore any
of resistance.
samples tested should be considered unfit for future use.
NOTE 2—Experience has shown that some conductors recover their
conductive properties if allowed to stabilize after the dynamic portion of
the test. Therefore, continuous monitoring is necessary.
1
This test method is under the jurisdiction of ASTM Committee F01 on
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
6. Test Samples
Switches.
Current edition approved June 15, 2009. Published November 2009. Originally
6.1 The test samples may be components, tail assembles or
approved in 2008. Last previous edition approved in 2008 as F 2749-08. DOI:
10.1520/F2749-09. finished switches. If the sample length is too short for the test
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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F2749 − 09
FIG. 1 Test Fixture Setup
fixture, a sample coupon of the same construction (layer to 7.1.2 Loop the unsecured end (dynamic end) of the test
layer) must be provided (minimum; 250 mm length by 25 mm
sample underneath the static portion.
width).
7.1.3 Clamp the dynamic end of the test sample to the
6.2 The width of the test sample must not exceed the length dynamic position of the test fixture.
of the roller.
7.1.3.1 Ensure that the both ends of the test sample remain
aligned (one on top of another) during motion of test.
7. Procedure
7.1.4 Connect to the test sample so that circuit resistance
7.1 Refer to Fig. 1 – drawing of mechanical hook up.
can be monitored continuo
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:F2749–08 Designation:F2749–09
Standard Test Method for
Determining the Effects of Creasing a Membrane Switch or
1
Assembly
This standard is issued under the fixed designation F 2749; 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
1.1 This test method establishes a method for the creasing of any part of a membrane switch with conductive circuits.
1.1.1 The values given in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.2 This standard does not purport to address all of the safety concerns, 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.
2. Terminology
2.1 Definitions:
2.1.1 crease—a ridge or groove made by folding and pressing.
2.1.1.1 Discussion—The fold mark in the substrate will be caused by a weightroller rolled over a fold that will likely remain
in the substrate after testing.
2.1.2 crease cycle—a 180 degree crease followed by a flatteningstraightening of the crease (see Fig. 1).
2.1.3 membrane switch—a momentary switching device in which at least one contact is on, or made of, a flexible substrate.
2.1.4 membrane switch tail—a flexible portion of a membrane switch used for input/output connection.
3. Significance and Use
3.1 Creasing of membrane switches or their components can affect their visual appearance, mechanical integrity or electrical
functionality. This practice simulates conditions that may be seen during manufacture, installation or use.
3.2 Crease testing may be destructive, therefore any samples tested should be considered unfit for future use.
3.3 Specific areas of testing include, but are not limited to:
3.3.1 Membrane switch flex tails, and
3.3.2 Any component of a membrane switch that may be subjected to bending. creasing.
4. Interferences
4.1 The following parameters may affect the results of this test:
4.1.1 temperature,
4.1.2 humidity, and
4.1.3 orientation of the conductor (either extension or compression) could have significant impact on the results.
4.1.4 Inelasticity and parallelism of roller and test bed will affect the displacement of the force across the sample. In other
words, the roller and test bed must not be compressible or subject to warping or distortion during the test cycle. Furthermore, the
roller must remain parallel to the test bed through the entire test cycle.
NOTE 1—Experience has shown that some conductors recover their conductive properties if allowed to stabilize after the dynamic portion of the test.
Therefore, continuous monitoring is necessary.
5. Apparatus
5.1 CylinderRoller, allowed to rotate smoothly around its longitudinal axis, rigid, low friction smooth surface.
5.1.1 Cylinder 2” Specification , 1 kg in size, measuring 50.8 mm (2 in.) in diameter by 68.6 mm (2.7 in.) in height. Weight
and dimensions of weight to be within 65%.
5.1.2Cylinder 1” Specification , 2 kg in size, measuring 63.5 mm (2.5 in.) in diametr by 86.4 mm (3.4 in.) in height. Weight and
dimensions of weight to be within 65%.
1
This test method is under the jurisdiction of ASTM Committee F01 on Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane Switches.
Current edition approved Nov. 1, 2008. Published December 2008.
Current edition approved June 15, 2009. Published July 2009. Originally approved in 2008. Last previous edition approved in 2008 as F 2749-08.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
F2749–09
FIG. 1 Test Fixture Setup
5.1.3Other Specifications—Dimensions or weight/force to be specified. Roller, measuring 50.8 mm (2 in.) in diameter, tolerance
65%.
5.2 Fixture to hold test sample securely in place in a horizontal manner (refer to Fig. 1).
5.3 Mechanisms capable of providing a consistentconstant force and rate of travel to the test sample. roller.
5.4 Equipment for the continuous monitoring and recording of resistance.
NOTE 2—Experience has shown that some conductors recover their conductive properties if allowed to stabilize after the dynamic portion of the test.
Therefore, continuous monitoring is
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