The Exchange Test Method
LABORATORY TEST METHOD NO. H-15: OPACITY OF PLASTIC/PAPER PRODUCTS
Issue Date: 30 Apr 1993
Revision Date:09/30/2011
PURPOSE:
To determine the opaqueness/opacity or "see through" characteristics of plastic sheeting/films or paper products.
PRINCIPLE:
Photo-volt meter is used to measure light reflectance of the item with a white backing and black backing to differentiate the "See through" characteristics.
NOTE: The reflectance of plastic/paper is higher when combined with a white backing than when combined with a black backing because, in the former case, light transmitted through the imperfectly opaque material is largely reflected by the white backing and a portion of the light, thus reflected, is transmitted through the material a second time.
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APPARATUS AND MATERIALS:
- ASTM D 589-97 (2002) Standard Test Method for Opacity of Paper
- ASTM D 2103-10 Standard Specifications for Polyethylene Film and Sheeting
- ASTM D 1746-09 Standard Test Method for Transparency of Plastic Sheeting
- ASTM D 1003-11 Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics
- Photo-volt meter user instructions/manual
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PROCEDURE:
- 4.1 Photo-volt meter -Model #575 or equivalent
- 4.2 Search Unit -Type "Y" Model #04-575-01 or equivalent
- 4.3 Opacity Chart Panels (Form 3B) available from Paul N. Gardner Co., Inc., Pomano Beach, FL
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EVALUATION:
- 5.1 Calibrate the photo-volt meter following user's instructions
- 5.2 Place plastic/paper material to be tested on the white area of the opacity chart and adjust the photo-volt meter to read 100. This will set meter to read light reflected by white background at 100%.
- 5.3 Place the plastic/paper material on the black area of the opacity chart sheet and read the reflectance value. This is the opacity of the sample tested.
6. REPORT
Report the opacity in percent as an average of at least five readings.