Interpretation ID: aiam3814
Plastic Products Dev. & Marketing Div.
Asahi Glass Co.
Ltd.
1-2
Marunouchi
2-Chome
Chiyoda-ku
Tokyo
100
Japan;
Dear Mr. Miyauchi: This responds to your letter to Mr. Francis Armstrong asking severa questions about Standard No. 205, *Glazing Materials*. The answers to your questions are discussed below.; Your first question concerned the requirements of Weathering Test No 16 of American National Standard Institute Z-26. The version of ANSI Z-26 currently incorporated by reference in Standard No. 205 is ANSI Z-26.1-1977, as supplemented by Z-26.1a, July 3, 1980, rather than ANSI Z-26.1- 1977 as cited in your letter. Your question has to do with the language of section 5.16.3 of ANSI Z-26, which states that after the weathering test, 'the decrease in regular (parallel) luminous transmittance of the irradiated specimen shall not exceed 5 percent.' You ask whether the permissible decrease is an absolute 5 percentage points (defined as A-B, where A is the luminous transmittance before the test and B is the luminous transmittance after the test) or is a relative decrease of 5 percent (defined as (A-B)/A). The permissible decrease is a relative decrease of 5 percent (defined as (A-B/A), or stated another way, the irradiated specimen must have 95 percent of its original transmittance after the test.; You also asked if Weathering Test No. 16 applies to AS-7 glazin materials. As required by Table 1 of ANSI Z-26, the weathering test does apply to AS-7 glazing materials.; Finally, you asked which DOT number, yours or the resin maker's, shoul be applied to a motorcycle windshield you make with an injection machine from polycarbonate resin pellets. Your DOT number must be used, since you fabricate the actual item of glazing material that will be placed in a vehicle.; Sincerely, Frank Berndt, Chief Counsel