ASTM F2749-08

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F2749–08
Standard Test Method for
Determining the Effects of Creasing a Membrane Switch or
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 3.3.2 Any component of a membrane switch that may be
subjected to bending.
1.1 Thistestmethodestablishesamethodforthecreasingof
any part of a membrane switch with conductive circuits.
4. Interferences
1.1.1 The values given in SI units are to be regarded as the
4.1 The following parameters may affect the results of this
standard. The values given in parentheses are for information
test:
only.
4.1.1 temperature,
1.2 This standard does not purport to address all of the
4.1.2 humidity, and
safety concerns, if any, associated with its use. It is the
4.1.3 orientation of the conductor (either extension or com-
responsibility of the user of this standard to establish appro-
pression) could have significant impact on the results.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Apparatus
2. Terminology 5.1 Cylinder, allowed to rotate smoothly around its longi-
tudinal axis, rigid, low friction smooth surface.
2.1 Definitions:
5.1.1 Cylinder 2” Specification,1kginsize,measuring50.8
2.1.1 crease—a ridge or groove made by folding and
mm (2 in.) in diameter by 68.6 mm (2.7 in.) in height. Weight
pressing.
and dimensions of weight to be within 65%.
2.1.1.1 Discussion—The fold mark in the substrate will be
5.1.2 Cylinder 1” Specification,2kginsize,measuring63.5
caused by a weight rolled over a fold that will likely remain in
mm (2.5 in.) in diametr by 86.4 mm (3.4 in.) in height. Weight
the substrate after testing.
and dimensions of weight to be within 65%.
2.1.2 crease cycle—a 180 degree crease followed by a
5.1.3 Other Specifications—Dimensions or weight/force to
flattening of the crease (see Fig. 1).
be specified.
2.1.3 membrane switch—a momentary switching device in
5.2 Fixture to hold test sample securely in place in a
which at least one contact is on, or made of, a flexible
horizontal manner (refer to Fig. 1).
substrate.
5.3 Mechanisms capable of providing a consistent force and
2.1.4 membrane switch tail—a flexible portion of a mem-
rate of travel to the test sample.
brane switch used for input/output connection.
5.4 Equipment for the continuous monitoring and recording
3. Significance and Use of resistance.
3.1 Creasingofmembraneswitchesortheircomponentscan
6. Test Samples
affecttheirvisualappearance,mechanicalintegrityorelectrical
6.1 The test samples may be components, tail assembles or
functionality. This practice simulates conditions that may be
finished switches. If the sample length is too short for the test
seen during manufacture, installation or use.
fixture, a sample coupon of the same construction (layer to
3.2 Crease testing may be destructive, therefore any
layer) must be provided (minimum; 250 mm length by 25 mm
samples tested should be considered unfit for future use.
width).
3.3 Specific areas of testing include, but are not limited to:
6.2 The width of the test sample must not exceed the length
3.3.1 Membrane switch flex tails, and
of the cylinder.
7. Procedure
This test method is under the jurisdiction of ASTM Committee F01 on
7.1 Refer to Fig. 1 – drawing of electrical/mechanical hook
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
up.
Switches.
7.1.1 Clamp one end of the test sample to the test fixture –
Current edition approved Nov. 1, 2008. Published
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