ASTM D7477-08
(Test Method)Standard Test Method for Determining the Area Stability of Wet Blue Submersed in Boiling Water
Standard Test Method for Determining the Area Stability of Wet Blue Submersed in Boiling Water
SIGNIFICANCE AND USE
Determination of the hydro-thermal area stability of wet blue provides information concerning the efficacy of the tanning process as well as the adequacy of the wet blue for intended end use applications where area stability is a particular requirement. Relative area stability of chrome-tanned leather is a requirement for many applications such as bookbinding, shoe and boot components, upholstery, seals and gaskets, etc.
This test method is suitable for use in development work and process control in the tannery and for specification testing of wet blue for domestic and international commercial purposes.
SCOPE
1.1 This test method provides a standard procedure for determination of the dimensional stability or area shrinkage of a specimen of wet blue that is submersed in boiling water for a specified time period. This test method is applicable to all types of wet blue.
1.2 The values given in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D7477 − 08
StandardTest Method for
Determining the Area Stability of Wet Blue Submersed in
Boiling Water
This standard is issued under the fixed designation D7477; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope reaches 100°C and begins to re-boil. As soon as the specimen
has cooled sufficiently to allow comfortable handling the area
1.1 This test method provides a standard procedure for
loss is determined.
determination of the dimensional stability or area shrinkage of
a specimen of wet blue that is submersed in boiling water for
4. Significance and Use
a specified time period. This test method is applicable to all
4.1 Determination of the hydro-thermal area stability of wet
types of wet blue.
blue provides information concerning the efficacy of the
1.2 The values given in SI units are to be regarded as the
tanning process as well as the adequacy of the wet blue for
standard. The inch-pound units given in parentheses are for
intended end use applications where area stability is a particu-
information only.
lar requirement. Relative area stability of chrome-tanned
1.3 This standard does not purport to address all of the leather is a requirement for many applications such as
bookbinding, shoe and boot components, upholstery, seals and
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- gaskets, etc.
priate safety and health practices and determine the applica-
4.2 Thistestmethodissuitableforuseindevelopmentwork
bility of regulatory limitations prior to use.
and process control in the tannery and for specification testing
of wet blue for domestic and international commercial pur-
2. Referenced Documents
poses.
2.1 ASTM Standards:
5. Apparatus
D6659Practice for Sampling and Preparation of Wet Blue
5.1 Beaker, standard, IL capacity. Other suitable containers
for Physical and Chemical Tests
E691Practice for Conducting an Interlaboratory Study to may be used so long as the dimensions are sufficiently large to
enable suspension of the completely immersed test specimen
Determine the Precision of a Test Method
E177Practice for Use of the Terms Precision and Bias in with no contact occurring with the sides and bottom of the
container during the test. Particularly when non-standard test
ASTM Test Methods
specimens are used, the size and shape requirements of the
container are dependent on the dimensions of the specimen to
3. Summary of Test Method
be tested.
3.1 Asample cutting of wet blue is either taken directly out
5.2 Thermometer,withaminimumscalereadingto+110°C,
of the tanning drum or else is pre-soaked in water for 30 min
graduated in 1°C, and having a 0.5°C tolerance.
or until it is completely re-hydrated (see 9.1 for details on
re-hydration). The specimen to be tested is cut out from this
5.3 Timer, with minimum 3 min capacity and 1.0 s resolu-
thoroughly hydrated sample cutting. The test specimen is then
tion.
totally submerged and suspended in boiling water. The test
5.4 Metal die, to cut specimens. The die should be con-
specimen is removed 3.0 min after the water temperature
structed of highly corrosion resistant alloy metal and must be
maintained in a clean and sharp condition to minimize distor-
tionofthewetbluesamplethatmayoccurduringthespecimen
This test method is under the jurisdiction ofASTM Committee D31 on Leather
cuttingoperation.Therecommendedspecimenisasquare76.2
and is the direct responsibility of Subcommittee D31.02 on Wet Blue.
by 76.2 mm (3.00 by 3.00 in.). However, other size and shape
Current edition approved Sept. 1, 2008. Published September 2008. DOI:
specimens can be used so long as the requirements of Section
10.1520/D7477-08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 8 are met.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.5 Measuring scale, ruler longer than the greatest dimen-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. sion of the test specimen, divided in millimeters ( ⁄32 in.).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7477 − 08
the dimensional loss values will give adequate results without going
5.6 Marking pen, Suitable water-proof marker or pen for
through the mathematical calculations.
marking the indicator points, on the hydrated wet blue grain
surface, to be used for measuring the specimen dimensions. 8.3 Appropriate small holes may be punched in the test
specimen to facilitate the suspension of the submerged speci-
6. Reagents and Materials meninthebeakerofwaterduringthetestifJ-hooksorS-hooks
are used in conjunction with a rod across the top of the beaker.
6.1 Water, distilled or de-ionized laboratory water should be
Alternative practices may provide suspension of the specimen
used, especially if there is any possibility of constituents in the
by employing a net type structure attached to a rod across the
available tap water affecting the results of this test.
top of the beaker.
6.2 Glycerin (Glycerol), technical grade is adequate.
9. Procedure
6.3 Salt (Sodium Chloride), common table salt is adequate.
9.1 Cuttings that are taken directly out of the tanning drum
7. Hazards
prior to dumping and wringing need not be re-hydrated.
Thorough hydration of the original sample cutting taken from
7.1 Allreagentsandchemicalsshouldbehandledwithcare.
wet blue after wringing shall be ensured by pre-soaking this
Before using any chemical, read and follow all safety precau-
cuttingforaminimum30minoruntilthecuttingiscompletely
tions and instructions on the manufacturer’s label or MSDS
re-hydrated. All soaking for re-hydration should take place
(Material Safety Data Sheet).
under ambient temperature conditions at the testing location.
Cuttings taken from wet blue after wringing and that have not
8. Test Specimen
dried out usually re-hydrate within 30 min. Wet blue cuttings
8.1 Theoriginalsamplecuttingtobepre-soakedandthetest
that have dried out somewhat may require significantly more
specimencutfromitshallbetakenfromthewetblueaccording
than 30 min to become completely re-hydrated. Wet blue
to Practice D6659. Specifically, for a hide or side the cutting
cuttings that have become significantly air-dried may require
shall be taken from the “a” test area (the kidney area) of a hide
soaking periods as long as overnight to re-hydrate completely.
or side. The number of samples to be tested shall be as
Re-hydration of the sample cutting can be accomplished by
described in Practice D6659 and need not be more than 12 per
soaking in a container or tray so long as the cutting is
50 000 ft of wet blue stock.
completely covered with water. Bending or flexing the cutting
8.2 The sample cutting taken from the wet blue should be
while it is completely immersed in water or application of a
large enough to permit the test specimen to be cut out with a
vacuum to facilitate removal of entrapped air may facilitate
fresh edge no closer than 13 mm (0.5 in) to an edge of the
re-hydration. Complete hydration should be determined by
original cutting. The sample cutting from which the test
weighingthesampleatappropriateintervalsduringthesoaking
specimen should be taken, should have minimum dimensions
processuntilconstantweightisachieved.Appropriateintervals
of approximately 101 by 101 mm (4 by 4 in.).Acutting taken
between weighings could be 10-15 min for cuttings that have
straight out of the tanning drum prior to wringing need not be
been wrung but not dried out and 30-60 min or more for
pre-soaked and the test specimen can be cut out directly from
cuttings that have dried out significantly. Constant weight is
this sample cutting.Acutting taken from wet blue at any point
achieved when the difference between successive weighings is
from the wringing operation forward will need to be pre-
less than 60.1 g. After the cutting has been completely
soaked (see 9.1 for details on re-hydration). The standard test
re-hydrated, the test specimen can be cut out from it.
specimen shall be a square 76.0 mm (3.00 in.) on edge. Other
9.2 Before the test specimen is cut out from the completely
size and shape specimens can be used. It is recommended that
hydrated cutting, the beaker of boiling water shall be prepared
for non-standard test specimens the minimum dimension (for a
so it is ready when the test specimen is cut out.A1Lbeaker or
sideofarectangleordiameterofacircle)be51.0mm(2.0in.)
other container shall be filled with sufficient water to gener-
and the maximum dimension (for a side or diameter ) be 102
ously cover the test specimen when fully immersed, but
mm (4.0 in.). Before a test specimen of non-standard dimen-
leavingsufficientroomtoenabletheimmersionandremovalof
sions may be used with this test method it must be rigorously
thetestspecimenwithoutcausingspillageofexcesswateronto
demonstrated that the non-standard specimen gives identical
the hotplate surface. The water shall be brought to boil. If the
results to that of the standard specimen for the particular wet
temperature is not exactly 100 6 0.5ºC sufficient glycerin or
blue being tested.
salt shall be added to bring the boiling point up to but not
NOTE 1—As an example of a non-standard specimen, a convenient size
exceeding 100ºC.
for test specimens could be a square exactly 100 mm on edge. Then, on
thisspecimen,alossof1mmineachdimensionisapproxi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.