ASTM D6915-03

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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Designation: D 6915 – 03
Standard Practice for
Carbon Black—Evaluation of Standard Reference Blacks
This standard is issued under the fixed designation D 6915; 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 3.3 The carbon black grades to be used as SRBs should be
selected to give as much coverage of the typical usage range
1.1 This practice covers guidelines for the production and
for each test and as nearly evenly spaced across the range as
testing for uniformity of a set of carbon blacks to be used as
possible. Typically, the carbon black grades selected consist of
Standard Reference Blacks (SRBs).
three tread (hard) type furnace grades (designated A, B, and C),
1.2 The values stated in SI units are to be regarded as the
three carcass (soft) type furnace grades (designated D, E, and
standard. The values given in parentheses are for information
F), and one thermal type grade (designated G). Subcommittee
only.
D24.61 may elect to carry one or more of the existing SRBs
1.3 This standard does not purport to address all of the
into the next set provided there is enough remaining material at
safety concerns, if any, associated with its use. It is the
the rate of usage to last through the expected life of the next
responsibility of the user of this standard to establish appro-
set. Limiting the choice of grades to be used means that not all
priate safety and health practices and determine the applica-
tests will have an SRB set that is evenly spaced across the
bility of regulatory limitations prior to use.
range of interest. All the SRB candidates are produced at
2. Referenced Documents
approximately the same time by the various producers. They
are used as a set once they are approved. The sets are
2.1 ASTM Standards:
consecutively numbered. Values and identification for the
D 1510 Test Method for Carbon Black—Iodine Adsorption
current set are given in Guide D 4821. Any SRBs carried
Number
forward will be renumbered for the new set.
D 1765 Classification System for Carbon Blacks Used in
Rubber Products
4. Production, Quality Control, and Quality Assurance
D 2414 Test Method for Carbon Black—Oil Absorption
4.1 It is assumed that manufacturers of the SRBs will use
Number
state-of-the-art techniques to ensure maximum uniformity
D 3265 Test Method for Carbon Black—Tint Strength
throughout the entire production run. The production should be
D 3493 Test Method for Carbon Black—Oil Absorption
made in one continuous production and packaging lot run. The
Number of Compressed Sample
testing called for in this practice is not intended to be a
D 4483 Practice for Determining Precision for Test Method
substitute for in-process quality control. This interlaboratory
Standards in the Rubber and Carbon Black Industries
study is only adequate to verify the quality of a homogeneous
D 4821 Guide for Carbon Black—Validation of Test
lot.
Method Precision and Bias
4.2 The size of the lot for each SRB is determined by
D 6556 Test Method for Carbon Black—Total and External
historical records on the rate of use. The lot should have an
Surface Area by Nitrogen Adsorption
expected life of about 5 years at the most recent rate of use.
3. Significance and Use
Historically, the lot size has usually been 10 000 lb.
3.1 This practice is intended to ensure that SRBs are
5. Sampling
produced and evaluated by a standard procedure.
5.1 The samples for determining lot uniformity shall be
3.2 This practice is to be used to establish the average
taken at the same time as when the SRB is packaged. Knowing
physicochemical properties of a set of carbon blacks to be used
the lot size, the total number of 22.7-kg (50-lb) bags needed to
as SRBs.
prepare the lot can be calculated. For example, for a 4540 kg
(10 000 lb) lot this would be 211 bags. The samples are
This practice is under the jurisdiction of ASTM Committee D24 on Carbon collected in addition to the number needed for the lot. Eleven
Black and is the direct responsibility of Subcommittee D24.61 on Carbon Black
samples will be taken consisting of the fifth bag pulled, and one
Sampling and Statistical Analysis.
bag representing one-tenth of the lot from there, through the
Current edition approved June 10, 2003. Published June 2003.
last bag. For example, for 200 bags the 5th, 25th
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