ASTM D2258-99

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Designation:D2258–99
Standard Practice for
Sampling Yarn for Testing
This standard is issued under the fixed designation D 2258; 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 4271 Practice forWriting Statements on Sampling inTest
Methods for Textiles
1.1 This practice describes a procedure for the division of
shipments of yarn into test lots and the sampling of such lots
3. Terminology
for testing.
3.1 Definitions:
1.2 This practice is applicable to single, plied, or cabled
3.1.1 beam, n—in textiles, a large spool containing many
yarns, and cords, made of any fiber or mixture of fibers, and
ends of yarns wound parallel, and used for such purposes as
supported on any form of package, including beams.
weaving or warp knitting.
1.3 This practice also describes procedures for the sampling
3.1.2 beam set, n—in textiles, one or more beams of yarn in
of yarn(s) removed from woven or knitted fabrics, however,
a single shipment to be further processed together for a specific
when thus sampled, the yarns are usually not representative of
end use.
entire shipments, as referred to in 1.1. Consequently, the
3.1.3 bulk sample, n— in the sampling of bulk material, one
resultant sampling can only be used to determine the charac-
or more portions which (1) are taken from material that does
teristics of the yarn and is usually not used for acceptance
not consist of separately identifiable units and (2) can be
testing. Moreover, it should be recognized that the character-
identified after sampling as separate or composited units.
istics of yarns from fabrics may be different than the charac-
3.1.4 case, n—in textiles, a shipping unit, usually a carton,
teristics of the same yarn(s), prior to being entered into the
box, bale, or other container holding a number of yarn
fabric manufacturing process.
packages.
1.4 The values stated in either SI units or inch-pound units
3.1.5 cone, n—in textiles, (1) a yarn holder or bobbin of
are to be regarded separately as the standard. Within the text,
conical shape used as a core for a yarn package of conical
the inch-pound units are shown in parentheses. The values
form, also called a cone core. (2) the yarn package obtained
stated in each system are not exact equivalents; therefore, each
when yarn is wound upon a cone core.
system shall be used independently of the other. Combining
3.1.6 end, n—an individual sliver, roving, yarn, or cord.
values from the two systems may result in nonconformance
3.1.6.1 Discussion—For yarns, one of the one or more
with this practice.
continuous, multiple parallel lengths of yarn which may be
1.5 This standard does not purport to address all of the
wound on a yarn package or beam. For example, two lengths
safety concerns, if any, associated with its use. It is the
of yarn wrapped parallel on a single bobbin constitute two yarn
responsibility of the user of this standard to establish appro-
ends, likewise, one thousand lengths of yarn wrapped parallel
priate safety and health practices and determine the applica-
on a single beam constitutes one thousand yarn ends.
bility of regulatory limitations prior to use.
3.1.7 fabric package, n—a length of fabric in a form
2. Referenced Documents suitable for handling, storing, or shipping.
3.1.7.1 Discussion—Fabric packages may be unsupported,
2.1 ASTM Standards:
such as when folded in cases, or supported, such as on tubes,
D 123 Terminology Relating to Textiles
bolts, or creels. Fabric packages are frequently referred to as
D 1578 Test Method for Breaking Strength of Skeins
rolls or pieces.
D 1907 Test Method for Yarn Number by the Skein
3.1.8 laboratory sample, n—a portion of material taken to
Method
represent the lot sample, or the original material, and used in
the laboratory as a source of test specimens.
This practice is under the jurisdiction of ASTM Committee D-13 on Textiles
and is the direct responsibility of Subcommittee D13.58 on Yarn Test Methods.
Current edition approved April 10, 1999. Published June 1999. Originally
published as D 2258 – 64T. Last previous edition D 2258 – 94.
2 3
Annual Book of ASTM Standards, Vol 07.01. Annual Book of ASTM Standards, Vol 07.02.
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D2258
3.1.9 lot, n—in acceptance sampling, that part of a consign- 5. Significance and Use
ment or shipment consisting of material from one production
5.1 Assigning a value to any property of the material in a
lot.
container or in a lot, consignment, or delivery involves a
3.1.10 lot sample, n—one or more shipping units taken at
measurement process that includes both sampling and testing
random to represent an acceptance sampling lot and used as a
procedures. The correctness of the value assigned depends
source of laboratory samples. (Syn. bulk sample)
upon the variability due to testing. Even when the variability
3.1.11 primary sampling unit, n—thesamplingunitcontain-
due to testing is minimized by carefully developed procedures,
ing all the sources of variability which should be considered in
correct and consistent estimates of the true value of the
acceptance testing; the sampling unit taken in the first stage of
property are possible only when the sampling procedure avoids
selection in any procedure for sampling a lot or shipment.
systematic bias, minimizes variations due to sampling, and
3.1.12 production lot, n—that part of one manufacturer’s
provides a laboratory sample of adequate size.
production made from the same nominal raw material under
5.2 Practice D 2258 may not give the most efficient sam-
essentially the same conditions and designed to meet the same
pling plan that might be devised in special situations but does
specifications.
present a general procedure that gives satisfactory precision
3.1.13 sample, n—(1) a portion of a lot of material which is
with an economical amount of sampling and one which does
taken for testing or for record purposes. (See also lot sample,
not require elaborate statistical computation based on previous
laboratory sample, and specimen); ( 2) a group of specimens
knowledge of the amount of variation between primary sam-
used, or observations made, which provides information that
pling units (such as cases, beams or fabric packages), between
can be used for making statistical inferences about the popu-
unitsofthelaboratorysampletakenfromtheprimarysampling
lation(s) from which they were drawn.
units of the lot sample (such as yarn packages taken from a
3.1.14 sampling unit, n—an identifiable, discrete unit or
case)andbetweenspecimenstakenfromunitsofthelaboratory
subunit of material that could be taken as part of a sample.
sample (such as lengths of yarn taken from a yarn package or
3.1.14.1 Discussion—Since there are two or more stages in a fabric swatch taken from a roll or piece). Many plans that
most sampling schemes, the sampling units in each stage must
include stratified sampling can be found in textbooks.
be clearly identified to avoid confusion. The number of stages
5.3 The smallest number of specimens required for a given
in sampling schemes is not limited, but may be as few or as
variability in the average result will usually be obtained by (1)
many as required by the nature of the material being sampled.
maximizing the number of shipping containers in the lot
There are frequently three stages of sampling: (1) taking
sample, (2) taking a single package end per shipping container
primary sampling units from a lot of material as a lot sample,
in the laboratory sample, and (3) taking only one specimen per
( 2) taking laboratory samples from each of the primary
package. Unfortunately, this is rarely the most economical way
sampling units in the lot sample, and (3) taking test specimens to test a product because it normally costs most to take a
from each of the units in the laboratory sample.
shipping container as part of the lot sample, costs an interme-
3.1.15 sample skein, n—skein reeled from the package or diate amount to take a package from a shipping container as
beam of the laboratory sample, and used in the laboratory as a
part of a laboratory sample, and costs least to take and test a
source of specimens. specimen from a package or yarn.
3.1.16 specimen, n—a specific portion of a material or 5.4 To minimize the cost of sampling a lot of material, it is
laboratory sample upon which a test is performed or which is
necessary to agree on the required variance for the reported
selected for that purpose. (Syn. test specimen.) average for a lot of material:
3.1.17 yarn package, n—a length or parallel lengths of yarn 5.4.1 Estimate the variance due to lot samples, the variance
in a form suitable for handling, storing, or shipping. due to laboratory samples, and the variance due to testing
3.1.17.1 Discussion—Packages may be unsupported, such specimens.
as skeins or cakes, or supported having various winding 5.4.2 Calculate the total variance for average test results for
patterns, such as bobbins, cops, cones, pirns, spools, or tubes. several combinations of the number of lot samples, the number
Inyarns,thewordpackagedesignatesthesmallestunitthatcan of laboratory samples per lot sample, and the number of
be separated from the shipment without cutting or unwinding specimens per laboratory sample.
the yarn, not a small group of packages. Even a small box 5.4.3 Calculate the cost of performing each of the sampling
containing a dozen spools is treated, for sampling purposes, as
schemes considered in 5.4.2.
a case. 5.4.4 Select the sampling scheme that ( 1) has the required
3.1.18 For terminology of other terms used in this practice, precision and (2) is most economical to perform.
refer to Terminology D 123.
6. Procedure
4. Summary of Practice
6.1 Division into Lots—Instructions on the division of
4.1 Instructions are given for dividing the yarn into lots, for product into lots is best given in the appropriate specification.
determining the number of cases, beams, or fabric packages to In the absence of such instructions, sample and test as a
be selected from each lot as a lot sample, and for determining separate lot any portion of a shipment or order that differs from
the number of packages, including the number of ends, other portions in specifications, put-up, or physical character-
representing those packages taken from the lot sample as a istics, or that is billed or designated by the supplier as a
laboratory sample. See Practice D 4271. separate lot. If portions of a larger order are shipped on
D2258
different dates, from plants or warehouses, or in more than one two packages from each case then randomly select two of the
carload or truckload, treat each such separately shipped portion fourcasesandselectrandomlyathirdpackagefromeachofthe
as a separate lot. If the cases in a shipment do not have selected cases. When there are three cases in the lot sample,
consecutive numbers, divide the shipment into groups of cases select randomly three packages from each case then randomly
having consecutive numbers and treat each group as a separate select one of the three cases and select randomly a fourth
lot if it is separated from an adjacent group by as many as ten package from the selected case. When there are two cases in
case numbers. Treat each beam set as a separate lot. the lot sample, select randomly five packages from each case.
6.2 Lot Sample—As a lot sample for acceptance testing, When there is one case in the lot sample, select randomly ten
unless otherwise agreed upon, as when specified in an appli- packages from the case.
cable material specification, proceed as follows: 6.3.2 Fabric Packages—When sampling fabric packages,
discard the outside layer of the fabric package, and then take a
NOTE 1—An adequate specification or other agreement between the
full width swatch,2m(2 yd.) from each selected lot sampling
purchaser and the supplier requires taking into account the variability
unit. Treat each type of yarn in the fabric, the warp and filling
between shipping units, between packages or ends within a shipping unit,
and between specimens from a single package so as to provide a sampling yarns in woven fabrics, and the machine direction of knitted
plan with a meaningful producer’s risk, consumer’s risk, acceptable
fabrics as sepa–rate sampling units. Take a total of ten ends
quality level, and limiting quality level.
from the fabric swatches. When there are five swatches in the
lot sample, select randomly two ends from each swatch. When
6.2.1 Cases or Fabric Packages—For the lot sample, assign
there are four swatches in the lot sample, select randomly two
each case or fabric package with consecutive numbers and take
ends from each swatch then randomly select two of the four
for acceptance testing, the number of cases or fabric packages
swatches and select randomly a third end from each of the
specified in Table 1. Select the cases or fabric packages by a
selected swatches. When there are three swatches in the lot
random process using the assigned numbers by either placing
sample, select randomly three ends from each swatch then
these numbers on small slips or chips, placing them in a
randomly select one of the three swatches and select randomly
container, mixing thoroughly and drawing out the number or
a fourth end from the selected swatch. When there are two
numbers by selection, or by using a random number table or its
swatchesinthelotsample,selectrandomlyfiveendsfromeach
computer equivalent.
swatch. When there is one swatch in the lot sample, select
6.2.1.1 When fabric packages, such as bolts or pieces, are
randomly ten ends from the swatch. Remove ends from the
contained in cases, consider the case as the sampling unit.
fabric swatches as directed in 6.3.4, 6.3.5, and 6.3.6, as
When fabric packages, such as rolls are self-contained, con-
required.
sider the individual fabric package as the sampling unit.
6.2.1.2 When known, fabric packages, such as rolls, pieces,
NOTE 2—Individual yarns removed from fabric may come from several
or bolts produced from one beam set may be treated in the
yarn shipments and may not be representative of a given yarn lot. Yarns
same manner as beams.
removed from fabric are generally used for identification purposes.
6.2.2 Beams—For the lot sample, assign each beam with
6.3.3 Beams—When sampling beams of yarn, take ten ends
consecutivenumbersandtakeforacceptancetesting,onebeam
from the first beam in the lot sample. Randomly t
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