ASTM D4583-95(1999)

Standard Practice for Carbon Black-Calculation of Process Indexes From an Analysis of Process Control Data

SCOPE
1.1 This practice provides: ( ) a statistical procedure for analyzing the test data generated in the statistical process control of a carbon black manufacturing process; ( ) a format for reporting process capability determined from the analysis of control chart data of an individual production run, and ( ) a format for reporting process performance determined from the analysis of control chart data of an individual production run.
1.2 This practice specifically applies to the analysis of pelleted carbon black samples taken during the manufacturing process prior to storage. This practice does not apply to shipment samples taken from hopper cars or other containers or packages.
1.3 This practice is specifically designed to be used for those test methods given in Classification D1765 which specify target values. However, these techniques are applicable to other test methods on carbon black.
1.4 This practice describes the calculation for two methods of determining capability factors from an analysis of process control data.
1.4.1 Process capability ( Cp ) is a measurement of variation calculated from the process control chart data with the use of an estimated standard deviation ([sigma]) from the mean value of the moving range ( ) chart. The calculation of the process capability ( Cp and Cpk ) indexes can be used as historical information or to predict future performance of the process, but are only valid when the process is in a state of statistical control.
1.4.2 Process performance ( Pp ) is a measurement of variation calculated from the process control chart data using sample standard deviation(s). The calculation of the process performance ( Pp and Ppk ) indexes are used for a historical reference of a process' performance and does not require a state of statistical control.

General Information

• Status: Historical
• Publication Date: 09-Dec-1999
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.61 - Carbon Black Sampling and Statistical Analysis

Relations

• Replaced By: ASTM D4583-95(2004) - Standard Practice for Carbon Black—Calculation of Process Indexes From an Analysis of Process Control Data
• Effective Date: 01-Jun-2004

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 4583 – 95 (Reapproved 1999)
Standard Practice for
Carbon Black—Calculation of Process Indexes From an
Analysis of Process Control Data
This standard is issued under the fixed designation D 4583; 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 D 1765 Classification System for Carbon Blacks Used in
Rubber Products
1.1 This practice provides: (1) a statistical procedure for
analyzing the test data generated in the statistical process
3. Terminology
control of a carbon black manufacturing process; ( 2) a format
,
3 4
3.1 Definitions of Terms Specific to This Standard:
for reporting process capability determined from the analysis
¯
3.1.1 average moving range ( R)—the arithmetic mean of n
of control chart data of an individual production run, and ( 3)
¯
moving ranges, R 5(R/n.
a format for reporting process performance determined from
3.1.2 Cpk index—an index that indicates how well the
the analysis of control chart data of an individual production
common cause process variability is actually contained within
run.
the specifications. (See 6.4.)
1.2 This practice specifically applies to the analysis of
3.1.3 moving range (R)—the absolute difference between
pelleted carbon black samples taken during the manufacturing
consecutive, individual test values.
process prior to storage. This practice does not apply to
3.1.4 Ppk index—indicates how well the common and
shipment samples taken from hopper cars or other containers or
special cause process variability is actually contained within
packages.
the specifications. (See 6.6.)
1.3 This practice is specifically designed to be used for
3.1.5 process capability index (Cp)—an index that com-
those test methods given in Classification D 1765 which
pares the magnitude of common cause process variability to the
specify target values. However, these techniques are applicable
range of upper and lower specification limits (USL and LSL)
to other test methods on carbon black.
without regard to where the process is centered; Cp
1.4 This practice describes the calculation for two methods
index 5 (USL − LSL)/(6sˆ ). (See 6.3.)
of determining capability factors from an analysis of process
3.1.6 process performance index(Pp)—an index that com-
control data.
pares the magnitude of common and special cause process
1.4.1 Process capability (Cp) is a measurement of variation
variability to the range of the upper and lower specification
calculated from the process control chart data with the use of
limits (USL and LSL) without regard to where the process is
an estimated standard deviation (sˆ ) from the mean value of the
centered; Pp index 5 (USL − LSL)/(6s). (See 6.5.)
moving range (R) chart. The calculation of the process capa-
bility (Cp and Cpk) indexes can be used as historical informa-
4. Significance and Use
tion or to predict future performance of the process, but are
4.1 This practice will provide the following: (1) a statistical
only valid when the process is in a state of statistical control.
summary of individual production run data plotted on a control
1.4.2 Process performance (Pp) is a measurement of varia-
chart; (2) a statistical summary of data from multiple produc-
tion calculated from the process control chart data using
tion runs; (3) a procedure to relate the average and variation of
sample standard deviation(s). The calculation of the process
these data groups to specification limits, and (4) indexes for
performance (Pp and Ppk) indexes are used for a historical
comparing different manufacturing units for projecting future
reference of a process’ performance and does not require a
capabilities or as historical reference.
state of statistical control.
2. Referenced Documents
2.1 ASTM Standards:
Annual Book of ASTM Standards, Vol 09.01.
Manual on Presentation of Data and Control Chart Analysis, STP 15D, ASTM,
This practice is under the jurisdiction of ASTM Committee D-24 on Carbon 1976.
Blackand is the direct responsibility of Subcommittee D24.61 on Carbon Black Ford Motor Company Manual on “Process Capability and Continuing Process
Sampling and Statistical Analysis. Control,” Publication No. 80-01-251. Available in packs of five from Ford Motor
Current edition approved Sept. 10, 1995. Published November 1995. Originally Company, Statistical Methods Publications, P.O. Box 1000, Plymouth, MI 48170
published as D 4583 – 86. Last previous edition D 4583 – 91. (313/322-4637).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4583
5. Procedure specifications. The Cpk index is inherently less than or equal to
the Cp index (for one-sided specifications, only the Cpk index
5.1 Sampling:
is applicable).
5.1.1 In order to provide uniformity and the ability to make
5.2.3 The Cp index indicates whether or not the process is
valid comparisons of process capability and process perfor-
mance indexes, all samples used for these calculations shall be capable of meeting a specification. Maximum performance is
collected in the same way. Samples that are to be tested for achieved when the process i
...