ASTM F1843-15

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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
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Designation: F1843 − 09 F1843 − 15
Standard Practice for
Sample Preparation of Transparent Plastic Films used on
Membrane Switch Overlays for Specular Gloss
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Measurements
This standard is issued under the fixed designation F1843; 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 practice covers the method of sample preparation, prior to taking gloss measurements on a membrane switch overlay.
1.2 Typical applications include window display areas on a graphic overlay, and surface texture.
1.3 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. Referenced Documents
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2.1 ASTM Standards:
D523 Test Method for Specular Gloss
3. Terminology
3.1 Definitions:
3.1.1 membrane switch, n—a momentary switching device in which at least one contact is on (or made of) a flexible substrate.
3.1.2 specular gloss, n—the degree to which a surface simulates a perfect mirror in its capacity to reflect incident light.
3.1.3 overlay, n—the outer layer of a membrane switch on which the graphics are printed.
4. Summary of Practice
4.1 A water or alcohol droplet is placed on a black metal plate. The specimen to be measured is pressed down over the droplet.
Capillary action causes intimate contact between specimen and plate, thereby eliminating second surface reflection. Gloss readings
may then be taken in accordance with Test Method D523.
5. Significance and Use
5.1 Gloss measurements are used to qualify a raw material or finished product.
5.2 Sample preparation will effect the outcome of gloss readings. This practice will eliminate second surface reflection, and
allow a more accurate gloss reading of the substrate.
5.3 Materials which require this preparation include the following: clear or translucent substrates, colored transparent substrates,
and areas printed with clear, translucent, or transparent colored coatings.
6. Apparatus
6.1 Gloss Meter, in accordance with Test Method D523.
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6.2 Black Iodized Aluminum Test Plate , This plate is to be a hard, flat, smooth, matte black, nonporous surface. Gloss readings
should be between 4 to 12 gloss units, when measured with a 60° gloss meter. Plate size should be sufficient to allow the specimen
to be laid flat for readings, typically 12 by 12 in. (304.8 by 304.8 mm). Material thickness to be 0.062 in. ( 1.57 mm) or thicker.
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This practice is under the jurisdiction of ASTM Committee F01 on Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane Switches Printed
Electronics.
Current edition approved June 15,
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