ASTM D7241-22

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: D7241 − 22
Standard Test Method for
Pile Thickness of Finished Multilevel Pile Yarn Floor
Covering
This standard is issued under the fixed designation D7241; 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.
1. Scope D5823 Test Method for Tuft Height of Pile Floor Coverings
E122 Practice for Calculating Sample Size to Estimate,With
1.1 This test method covers the determination of pile
Specified Precision, the Average for a Characteristic of a
thickness of finished multilevel pile yarn floor covering using
Lot or Process
a thickness measuring instrument having a stationary surface
(platen), a circular pressure foot under specified force, and
3. Terminology
capable of being moved vertically above the platen.
3.1 For definitions of terms relating to Pile Floor Coverings,
1.2 Thistestmethodisapplicableonlytofinishedmultilevel
refer to the Terminology D5684.
loop pile constructions.
NOTE 1—Determination of pile thickness of multilevel pile yarn floor 3.2 Thefollowingtermsarerelevanttothisstandard:carpet,
coverings was previously contained within Test Method D418. For user
cut pile yarn floor covering, finished, finished pile yarn floor
convenience, Subcommittee D13.21 subdivided Test Method D418 into
covering, floor covering, pile, pile thickness, pile yarn floor
separate standards of which this test method is one.
covering, pitch, primary backing, shorn pile stubble, stubble
1.3 The values stated in inch-pound units are to be regarded
height, textile floor covering, tufted fabric.
as standard. The values given in parentheses are mathematical
3.3 For definitions of other terms related to textiles, refer to
conversions to SI units that are provided for information only
Terminology D123.
and are not considered standard.
3.4 For discussion of terminology specific to this standard,
1.4 This standard does not purport to address all of the
see Annex A1.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.1 The thickness and mass are measured on each selected
1.5 This international standard was developed in accor- strip specimen in the unsheared condition and after removing
dance with internationally recognized principles on standard-
approximately 25, 50, 75 % and all of the pile down to a
ization established in the Decision on Principles for the stubble by shearing. The net pile thicknesses at the 25, 50, and
Development of International Standards, Guides and Recom-
75 % levels are calculated by subtracting the stubble specimen
mendations issued by the World Trade Organization Technical thickness from the thicknesses measured at each of the other
Barriers to Trade (TBT) Committee.
stages. The net pile masses are calculated by subtracting the
mass of the stubble specimen from the four other weighings.
2. Referenced Documents
The 25, 50, and 75 % net masses are expressed as a percent of
thenetpilemassoftheunshearedspecimenandthe25,50,and
2.1 ASTM Standards:
75 % net thicknesses are plotted against these net mass
D123 Terminology Relating to Textiles
percentages.Asmooth curve is drawn through the three plotted
D1776 Practice for Conditioning and Testing Textiles
points. The net pile thickness corresponding to 50 % net mass
D5684 Terminology Relating to Pile Floor Coverings
is read from the smooth curve and doubled to obtain the
average pile thickness.
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.21 on Pile Floor Coverings.
5. Significance and Use
Current edition approved April 1, 2022. Published May 2022. Originally
5.1 The determination of pile thickness of multilevel pile
approved in 2006. Last previous edition approved in 2013 as D7241-13 which was
withdrawn in January 2022 and reinstated in April 2022. DOI: 10.1520/D7241-22.
yarn floor covering is useful in quality and cost control during
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
manufacture of pile yarn floor covering. The appearance and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
performance may be affected by changes in pile thickness of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. pile yarn floor coverings. This test method is considered
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7241 − 22
satisfactory for acceptance testing of commercial shipments 6.3 When a full-width sample is not available, take speci-
because current estimates of between laboratory precision are mens as directed in 6.1.4, and state in the report the width
acceptable, and this test method is commonly used in the trade available and the number of test specimens taken.
for acceptance testing.
7. Apparatus
5.2 If there are differences of practical significance between
reported test results for two laboratories (or more), compara-
7.1 Balance, capable of weighing to the nearest 0.01 g.
tive tests should be performed to determine if there is a
7.2 Shear or Clipper, capable of shearing close enough to
statistical bias between them, using competent statistical assis-
the backing so as to leave a stubble of no more than 0.05 in.
tance. As a minimum, use the samples for such comparative
(1.3 mm).
tests that are as homogenous as possible, drawn from the same
7.2.1 Means for adjusting the height of the shear, such as
lot of material as the samples that resulted in disparate results
shims or mechanical mount for a shearing head.
during initial testing and randomly assigned in equal numbers
7.3 Thickness Measuring Instrument:
to each laboratory. The test results from the laboratories
7.3.1 Having a stationary surface (plate) on which to place
involved should be compared using a statistical test for
the specimen, and a presser foot capable of being moved
unpaired data, a probability level chosen prior to the testing
series. If a bias is found either its cause must be found and vertically above the plate, at least 1 in. (25 mm) from the plate.
corrected, or future test results for that material must be 7.3.2 Havingtwointerchangeablepresserfeet;one1.000in.
adjusted in consideration of the known bias. 60.001in.(25.4mm 60.03mm)diameter,theother2.250in.
6 0.001 in. (57.15 mm 6 0.03 mm) in diameter.
6. Sampling, Test Specimens, and Test Units
7.3.3 Having means for indicating the vertical distance
between the presser foot and the plate to the nearest 0.001 in.
6.1 Sampling Units:
(0.03 mm) and capable of developing and indicating a force up
6.1.1 Coated Floor Covering—The basic sampling unit of
to 0.6 lbf (2.77 N) between the presser foot and the plate.
coated floor covering is a shipping roll. The number of
shipping rolls obtained from each production roll ranges from
7.4 Graph Paper, with 0.1 in. (2 mm) divisions.
one to over ten.
7.5 DraftingCurves, such as a set of French curves, flexible
6.1.2 Lot Sample—Take a lot sample as directed in Practice
curve, or software capable of drawing the graph.
E122 when statistical knowledge of the product variability and
test method precision is available, and a decision has been
8. Preparation of Apparatus
made on the maximum deviation that can be tolerated between
the estimate to be made from the sample and the result that
8.1 Attach the presser foot loosely to the moveable stem or
wouldbeobtainedbymeasuringeverysamplingunitofthelot.
head of the instrument and bring the presser foot into firm
Otherwisethenumberofsamplingunitsinalotsampleandthe
contact with the plate. Tighten the presser foot on the stem,
use of the test results obtained from the individual test samples
check the instrument zero by lowering the presser foot into
shall be in accordance with the manufacturer’s quality control
contact with the plate until the indicated pressure increases to
program or with the specification agreed upon between the
the pressure to be used in measuring the distance between the
purchaser and the supplier.
foot and the plate. The instrument must read 0 in. 6 0.001 in.
6.1.3 Laboratory Sampling Unit—A laboratory sampling
(0 mm 6 0.03 mm), if the reading is not within this range a
unit shall consist of a full width section of floor covering cut
adjustment shall be made appropriate to the type of instrument
from one end of each roll in the lot sample and shall be at least
being used. Verify the instrument with calibrated thickness
4 in. (100 mm) longer than the specimens required for the tests
blocks.
being conducted. Do not cut a laboratory sampling unit of
coated floor covering from a seam end of a production roll.
9. Conditioning
6.1.4 Test Specimens—A test specimen is a designated area
9.1 Condition the laboratory sampling unit or the test
cut from a laboratory sampling unit For laboratory sampling
specimens in the standard atmosphere for testing textiles, that
units120in.(3000mm)wideorwider,threetestspecimensare
is 70 °F 6 2 °F (21 °C 6 1 °C) at 65 6 2 % relative humidity,
required for a test method, one at each edge no nearer to the
12 h or until the mass changes no more than 0.1 % in2has
edge than 5 % of the total floor covering width and one in the
directed in Practice D1776.
middle portion of the test sample. For laboratory sampling
units at least 60 in. (1500 mm) wide but less than 120 in. (3000
10. Procedure
mm),taketwotestspecimens,oneateachedgenonearertothe
10.1 Select the number and location of the test specimens as
edge than 5 % of the total floor covering width. For laboratory
sampling units less than 120 in. (1500 mm) wide, take one test directed in Section 6. Prepare the test specimens according to
the procedure in Annex A2.
specimen from the middle.
6.2 Where it is known that systematic variations in a floor 10.2 The test specimens shall comprise a full pattern repeat
covering characteristic may occur in bands 18 in. (460 mm) or or a whole number multiple of a full pattern repeat in each
more in width, as with a modular pattern device having direction but no less than 9.9 in. 6 0.1 in. (250 mm 6 3 mm)
separate controls or adjustments for each module, take test in the lengthwise direction by 12.5 in. 6 0.1 in. (320 mm 6 3
specimens from the middle of each band. mm) in the widthwise direction. If the pattern repeat is not
D7241 − 22
known and cannot be determined readily, use 18.0 in. by 18.0v where:
6 0.1 in. (457 mm by 457 mm 6 3 mm) for the test specimen
T ,T ,T = target shearing thickness for 25, 50, and
25 50 75
dimensions.
75 % shearing, in. (mm),
Z = total thickness, T –h, in. (mm) and
o
10.3 Select a strip specimen from each of the test speci-
h = stubble thickness, approximate thickness of
mens. The strip specimens shall be 9.9 in. 6 0.1 in. (250 mm
backing material plus stubble, in. (mm).
6 3 mm) in the lengthwise direction and 2.5 in. 6 0.1 in. (64
10.6 25% Shearing:
mm 6 3 mm) in the widthwise direction and should be
10.6.1 Shear each strip specimen to a thickness of approxi-
conditioned as directed in Section 9.
mately t . Remove all loose fibers from the specimens.
10.3.1 Determine the total mass of all the strip specimens to
10.6.2 Attach the 2.250 in. (57.15 mm) presser foot loosely
the nearest 0.01 g and record as M , where the subscript zero
to the moveable stem of the instrument and bring the presser
indicates the strip specimens are unsheared.
footintofirmcontactwiththeplate.Tightenthepresserfooton
the stem. Check the instrument zero as directed in 8.1. Verify
10.4 Total Thickness:
the instrument with calibrated thickness blocks.
10.4.1 Attach the 2.250 in. (57.15 mm) presser foot as
10.6.3 Measure the 25 % sheared strip specimen thickness
directed in 8.1. For each strip specimen, raise the presser foot
at three different locations, average the measurements for all
and center the specimen, pile face up, on the plate under the
strip specimens and record the average as T , to the nearest
foot. Lower the presser foot slowly (take about5sto apply full
0.001 in. (0.03 mm).
load)ontothepilesurfaceuntilapressureof0.100psi 60.003
10.6.4 Determinethetotalmassofallthe25 %shearedstrip
psi (689 Pa 6 21 Pa) is exerted on the specimen. Read the
specimens and record to the nearest 0.01 g as M .
distance between the presser foot and the plate to the nearest
10.7 50% Shearing:
0.001 in. (0.03 mm). Determine the total thickness in three
10.7.1 Shear each strip specimen to a thickness of approxi-
different areas for each strip specimen and record the average
mately t . Remove all loose fibers from the specimens.
as the total thickness, T .
o
Measure the 50 % sheared strip specimen thickness at three
different locations, average the measurements for all strip
10.5 Estimation of Shearing Levels:
specimensandrecordtheaverageasT ,tothenearest0.001in.
10.5.1 Obtain an approximate stubble specimen thickness
(0.03 mm).
by shearing the pile down to a stubble measuring approxi-
10.7.2 Determinethetotalmassofallthe50 %shearedstrip
mately 0.05 in. (1.3 mm).
specimens and record to the nearest 0.01 g as M .
10.5.2 Attach the 1.000 in. (25.40 mm) diameter presser
10.8 75% Shearing:
foot loosely to the stem and bring the presser foot into firm
10.8.1 Shear each strip specimen to a thickness of approxi-
contact with the plate. Tighten the presser foot on the stem.
mately T . Remove all loose fibers from the specimens.
Check the instrument zero as directed in 8.1. Verify the
Measure the 75 % sheared strip specimen thickness at three
instrument with calibrated thickness blocks.
different locations, average the measurements for all strip
10.5.3 For each stubble specimen, raise the presser foot and
specimensandrecordtheaverageasT ,tothenearest0.001in.
center the specimen, stubble side up, on the plate. Lower the
(0.03 mm).
presser foot onto the stubble surface until a pressure of 0.75 psi
10.8.2 Determinethetotalmassofallthe75 %shearedstrip
6 0.01 psi (5170 Pa 6 69 Pa) is exerted on the stubble
specimens and record to the nearest 0.01 g as M .
specimen. Read the distance between the presser foot and the
10.9 Stubble Shearing:
plate to the nearest 0.01 in. (0.03 mm). Determine the stubble
10.9.1 Shear each strip specimen as close to the back as
thickness in three different areas of the strip specimen and
possible (approximately 0.05 in. (1.3 mm)). Remove all loose
record the average as the stubble thickness h.
fibers from the specimens.
10.5.4 Obtain an approximate total pile thickness using Eq
10.9.2 Attach the 1.000 in. (25.40 mm) diameter presser
1:
foot loosely to the stem and bring the presser foot into firm
contact with the plate. Tighten the presser foot on the stem.
Z 5T 2h (1)
o
Check the instrument as directed in 8.1.
where:
10.9.3 Measure the stubble specimen thickness at three
Z = total pile thickness, in. (mm),
different locations, average the measurement for all strip
T = average total thickness, in. (mm), and
o specimens and record the average asT to the nearest 0.001 in.
h = average stubble thickness, in. (mm).
(0.03 mm).
10.9.4 Determine the total mass of
...