The specific gravity or density
of a solid is a property that is conveniently measured to identify a material,
to follow physical changes in a sample, to indicate degree of uniformity among
different sampling units or specimens, or to indicate the average density of a
large item.
Changes in density of a single
material are due to localized differences in crystallinity, loss of
plasticizer, absorption of solvent, or to other causes. It is possible that
portions of a sample differ in density because of their differences in
crystallinity, thermal history, porosity, and composition (types or proportions
of resin, plasticizer, pigment, or filler).
Density is useful for calculating
strength-weight and cost-weight ratios.
This can be tested as per ASTM D 792, ASTM D297 and also ISO 1183-1
Let see the testing video:
ASTM D297:
These test methods cover the qualitative and quantitative analyses of the composition of natural and synthetic crude rubbers.
These methods are divided into general and specific test methods.
General test methods shall be performed to determine the amount and type of some or all of the major constituents of a rubber product, and shall include determination of rubber polymer content by the indirect method, determination of density, and extract, sulfur, fillers, and ash analyses.
Specific test methods, on the other hand, shall be performed to determine specific rubber polymers present in a rubber product such as crude, unvulcanized, reclaimed, and vulcanized rubbers.
No comments:
Post a Comment