ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
During an investigation of the time for ignition of polymeric materials under the influence of radiant heating, it was found that the polymer surface reflectance-absorptance characteristics were a major factor in the variance of the ignition times. A subsequent research study was made of the reflectance-absorptance characteristics of those polymers used in the ignition testing. Reflectance values were obtained over the wavelength of 0.3 to 2.5 microns using a double-beam Cary model 14 spectrophotometer with an integrating sphere reflectometer and over the wavelengths of 1.0 to 10.0 microns using a Gier-Dunkle Hohlraum with a Perkin-Elmer spectrophotometer. Absorptance values were obtained by means of Kirchoff's Law,Drawings and graphs are included which illustrate the test apparatus and type of data collected. A table of average absorptances of several polymers are given and listed according to the particular type of heat source used. \documentclass{article}\pagestyle{empty}\begin{document}$$ \alpha _\lambda + r_\lambda = 1 $$\end{document} Average absorptances of the polymers over the monochromatic wavelength span of the heat sources were calculated using the equation \documentclass{article}\pagestyle{empty}\begin{document}$$ \alpha _{{\rm av}} = \frac{{\int_{\lambda _1 }^{\lambda _2 } {\alpha _\lambda e_\lambda d\lambda } }}{{\int_{\lambda _1 }^{\lambda _2 } {e_\lambda {\rm d}\lambda}}} $$\end{document} Mathematical analyses were developed and are presented for both the integrating sphere reflectometer and Gier-Dunkle Hohlraum unit.Drawings and graphs are included which illustrate the test apparatus and type of data collected. A table of average absorptances of several polymers are given and listed according to the particular type of heat source used.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760141010
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