What a density match tells you
Density is the mass of a specimen divided by its volume. Different blends can land at the same ratio because the base polymer, additives and fillers contribute differently to those two quantities. If a specimen contains voids, its apparent density can also differ from that of solid material. Two values reported to the same number of decimal places may simply be indistinguishable at the resolution of the report.
Packaging sample showroom of SamBound New Material Technology Company Ltd. (sambound.com).
How to compare two molded samples
Request the method, specimen location, conditioning and measurement temperature. In an immersion measurement, trapped air can bias the volume estimate. A finished part with an insert, coating or hollow section answers a different question from a solid specimen cut from the molding. Compare replicate specimens prepared the same way and retain the actual measurement precision.
A buyer can use density to flag a change in a familiar grade. To investigate an unknown substitution, confirm the grade and lot through material records and use a complementary method suited to the suspected difference. A matching density alone leaves resin identity, additive content and finished-part performance unresolved.
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