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Ultrasonic velocity measurement for the determination of density in polyethylene
Author(s) -
Piché L.
Publication year - 1984
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760241713
Subject(s) - ultrasonic sensor , materials science , acoustics , polyethylene , speed of sound , range (aeronautics) , accuracy and precision , density gradient , optics , composite material , physics , statistics , mathematics , quantum mechanics
An ultrasonic immersion method is presented for the rapid and accurate measurement of longitudinal sound velocity (v) in polyethylene (PE). The method is based solely on the measurement of time delays and can be automated. The samples are the same press‐molded plaques that are prepared for the standard‐density (ρ) determination using a density‐gradient column, Our measurements on a representative group of various types of PE with densities in the range 0.92 to 0.96 g/cm 3 show without ambiguity that v is proportional to ρ. The degree of correlation is such that we come to suggest that the acoustic method be used for the characterization of density. We show that the accuracy is good and compares with that of the density‐gradient column and we then conclude on the practical advantages of the ultrasonic method.