ASTM D3790-79(2001)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D3790–79(Reapproved2001)
Standard Test Method for
Volatile Matter (Moisture) of Leather by Oven Drying
This standard is issued under the fixed designation D 3790; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope oven drying, (d) shape of the weighing container, and (e) type
of oven (gravity versus mechanical convection) used.
1.1 This test method covers the determination of volatile
4.5 Because of the above unknown errors, the result of this
matter (moisture) in all types of leather.
test is a purely arbitrary value for the moisture content of the
1.2 This standard does not purport to address all of the
sample. It is, therefore, essential that the method be followed
safety concerns, if any, associated with its use. It is the
exactly in order to obtain reproducible results among labora-
responsibility of the user of this standard to establish appro-
tories.This is particularly true if other chemical analytical tests
priate safety and health practices and determine the applica-
being performed on the same sample are reported on the
bility of regulatory limitations prior to use.
moisture-free basis.
2. Referenced Documents
5. Apparatus
2.1 ASTM Standards:
5.1 Weighing Bottle , glass, low-form, cylindrical with a
D 2813 Practice for Sampling Leather for Physical and
2 ground-glassstopperofstandardtaper.Thebottleshallhave70
Chemical Tests
6 5 mm inside diameter, and 33 6 3 mm overall height.
E 180 Practice for Determining the Precision of ASTM
5.2 Oven, mechanical-convection draft capable of setting at
Methods forAnalysis and Testing of Industrial Chemicals
100°C, with a thermoregulator system capable of holding oven
3. Summary of Test Method temperature within 6 2°C of set point.Athermometer accurate
to 60.2°C should be used to check and monitor the oven set
3.1 The ground leather specimen is heated in a mechanical-
point.
convection oven for 16 h at 100°C, placed in a desiccator,
5.3 Balance, capable of weighing up to 100 g with an
cooled, and reweighed. The loss in weight represents the
accuracy of 60.001 g.
volatile matter.
5.4 Desiccator, any convenient form or size, using any
4. Significance and Use
normal desiccating agent such as calcium sulfate, calcium
chloride, or silica gel.
4.1 Theresultobtainedbythistestisnormallyconsideredto
be the moisture content of the leather sample. This result is
6. Sampling
used to correct all other chemical tests to a moisture-free basis.
6.1 TheleathershallbesampledinaccordancewithPractice
4.2 Materials that are volatile under these conditions, other
D 2813.
thanwater,maybepresentintheleather,althoughtheiramount
in any normal leather would be expected to be a very small
7. Procedure
percentage of the total volatile matter.
7.1 Insert the empty weighing bottle inside the inverted
4.3 Under the conditions of this test, certain materials in
stopperedcapandplaceonashelfintheovenat100 62°Cfor
leather, such as protein fiber and chromium tanning salts, may
1 h or more. If the stopper has a handle then the stopper may
retain moisture. Other materials, such as tannins and oils, may
be placed on the shelf in the oven near the empty weighing
be oxidized. Both of these effects produce negative errors in
bottle.
the moisture determination.
7.2 Remove and place in a desiccator for at least 2 h to cool.
4.4 The amount of volatile matter (moisture) released by a
7.3 Weigh and record to the nearest 60.001 g.
given leather varies with (a) degree of grinding of the sample,
7.4 Use the ground leather sample as specified in Practice
(b) weight of sample taken, (c) temperature and time of the
D 2813 and transfer 5 6 1 g of ground leather into the
previously weighed weighing bottle and stopper the bottle.
This test method is under the jurisdiction ofASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.06 on Chemical Analysis—
Gen
...