ASTM D4204-16(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4204 − 16 (Reapproved 2023)
Standard Practice for
Preparing Plastic Film Specimens for a Round-Robin Study
This standard is issued under the fixed designation D4204; 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 (´) indicates an editorial change since the last revision or reapproval.
round-robin protocols often specify that replicate test results be obtained
1. Scope
on different days.
1.1 This practice covers the preparation of test sets of plastic
3.1.2 sample—a quantity of film of a width appropriate to
film specimens for subsequent use in an interlaboratory round-
the test method under study and of a length sufficient to yield
robin study to evaluate the precision of a test method.
the total number of film specimens needed for the planned
1.2 This standard does not purport to address all of the
round-robin study.
safety concerns, if any, associated with its use. It is the
3.1.3 test result—the value (usually, the arithmetic average)
responsibility of the user of this standard to establish appro-
of the property derived from one test unit.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.1.4 test set—a group of several film specimens, in a
number greater than that specified for a test unit.
NOTE 1—There is no known ISO equivalent to this standard.
1.3 This international standard was developed in accor-
3.1.5 test specimen—the individual piece of film to be
dance with internationally recognized principles on standard-
tested, usually of specified dimensions, that is to be cut from
ization established in the Decision on Principles for the one film specimen and tested, to produce one value of the
Development of International Standards, Guides and Recom-
property, or properties, by the test method under study.
mendations issued by the World Trade Organization Technical
3.1.6 test unit—a specified number of film specimens from
Barriers to Trade (TBT) Committee.
which an equal number of test specimens is to be prepared and
tested in a short-time span to yield one test result for each
2. Referenced Documents
property.
2.1 ASTM Standards:
3.2 Abbreviations:
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
RR = round-robin study
q = number of samples to be used in the RR
3. Terminology
r = total number of film assemblies that will be needed
for each lab to complete the necessary testing
3.1 Definitions of Terms Specific to This Standard:
n = specified number of film specimens in a test unit
3.1.1 film specimen—one piece of a sample obtained by 1
n = number of additional film specimens in each test set
cutting across the width of the sample and to a length such that
p = number of laboratories participating in the RR
one test specimen can subsequently be prepared.
p = number of additional “latent” laboratories provided
NOTE 2—For any sample in a laboratory, the specified number of film
for in the specimen preparation procedure
specimens in a test unit (n ) are tested to produce a single test result in a
L = film-specimen length appropriate for preparing one
short-time period, while replicate test results are obtained over a longer
test specimen
time period. Thus, there are within-laboratory components of variability
L = total length of film necessary to produce samples fro
for both short-term and long-term testing. This practice calls these
participating plus latent laboratories; L = (p + p )
within-day and between-day components of variability, inasmuch as
2 1 2
(L )
SD = standard deviation for a single source of variability
for one given sample
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and
is the direct responsibility of Subcommittee D20.19 on Film, Sheeting, and Molded
S = standard deviation for within-laboratory within-day
Products.
variability of a test value
Current edition approved Nov. 1, 2023. Published November 2023. Originally
S = standard deviation for within-laboratory variability of
approved in 1982. Last previous edition approved in 2016 as D4204 - 16. DOI:
a test result
10.1520/D4204-16R23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or S = standard deviation for between-laboratory variability
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
of a test result
Standards volume information, refer to the standard’s Document Summary page on
S = standard deviation for within-sample variability
the ASTM website.
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D4204 − 16 (2023)
5.1.3 The best source of samples is from commercial or
S = standard deviation of a within-laboratory single test
r
laboratory extrusion operations that have demonstrated the
result for one given sample on any day
capability to produce film under conditions that have shown
S = standard deviation of a between-laboratory single test
R
that appreciable systematic trends in the level of the property,
result for one given sample on any day
or properties, to be measured did not occur as the sample was
4. Significance and Use
being fabricated.
4.1 This practice is intended to assist task groups participat-
5.2 Before preparing test sets as described in Section 6, have
ing in a round-robin study with the preparation of test sets of
one laboratory test the specified number of test specimens (n )
film specimens from film samples in the form of rolls on a core.
from each sample. If the range of property levels thus found is
narrower than is deemed appropriate for the study, it is
4.2 This practice assumes that the essential features of the
desirable to obtain one or more additional samples, to replace
round-robin protocol have already been established by follow-
one or more of the number of samples to be used in the RR (q)
ing the guidance of Practice E691. In particular, it is assumed
collected initially.
that the following are known: (1) the number of film samples
to be used, (2) the number of participating laboratories, (3) the
6. Procedure
number of replicate test results to be generated by each
laboratory for each sample, and (4) the number of test
6.1 Determine the number of extra film specimens to be
specimens required to yield one test result for each sample.
used for each test (n ) for the RR. In view of the way test sets
4.3 In accordance with this practice, samples are partitioned are made up, as described subsequently, there will always be
into test sets so that real within-sample variability will not two “sacrifice” film specimens in a test set, one on top and one
unduly distort the conclusions drawn from statistical analyses on bottom of the stack, that serve to protect the integrity of the
of the data generated in the round-robin study. film specimens in between. These two are not to be used;
always take test specimens from film specimens between the
5. Sample Selection
top and bottom film specimens in the test set. In addition, it is
5.1 Select the number of samples q to be used in the usually advisabl
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