ASTM D6341-98
(Test Method)Standard Test Method for Determination of the Linear Coefficient of Thermal Expansion of Plastic Lumber and Plastic Lumber Shapes Between -30 and 140°F (-34.4 and 60°C)
Standard Test Method for Determination of the Linear Coefficient of Thermal Expansion of Plastic Lumber and Plastic Lumber Shapes Between -30 and 140°F (-34.4 and 60°C)
SCOPE
1.1 This test method covers the determination of the coefficient of linear thermal expansion for plastic lumber and plastic lumber shapes to two significant figures. The determination is made by taking measurements with a caliper at three discrete temperatures. At the test temperatures and under the stresses imposed, the plastic lumber shall have a negligible creep or elastic strain rate, or both, insofar as these properties would significantly affect the accuracy of the measurements.
1.1.1 This test method details the determination of the linear coefficient of thermal expansion of plastic lumber and plastic lumber shapes in their "as manufactured" form. As such, this is a test method for evaluating the properties of plastic lumber or shapes as a product and not a material property test method.
1.2 The thermal expansion of plastic lumber and shapes is composed of a reversible component on which may be super-imposed changes in length due to changes in moisture content, curing, loss of plasticizer or solvents, release of stresses, phase changes, voids, inclusions, and other factors. This test method is intended to determine the coefficient of linear thermal expansion under the exclusion of non-linear factors as far as possible. In general, it will not be possible to exclude the effect of these factors completely. For this reason, the test method can be expected to give a reasonable approximation but not necessarily precise determination of the linear coefficient of thermal expansion.
1.3 Plastic lumber and plastic lumber shapes are currently made predominately with recycled plastics where the product is non-homogeneous in the cross-section. However, this test method may also be applicable to similar manufactured plastic products made from virgin resins or other plastic composite materials.
1.4 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1-There is no similar or equivalent ISO standard.
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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 6341 – 98
Standard Test Method for
Determination of the Linear Coefficient of Thermal
Expansion of Plastic Lumber and Plastic Lumber Shapes
Between –30 and 140°F (–34.4 and 60°C)
This standard is issued under the fixed designation D 6341; 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 responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers the determination of the coef-
bility of regulatory limitations prior to use.
ficient of linear thermal expansion for plastic lumber and
plastic lumber shapes to two significant figures. The determi-
NOTE 1—There is no similar or equivalent ISO standard.
nation is made by taking measurements with a caliper at three
2. Referenced Documents
discrete temperatures. At the test temperatures and under the
stresses imposed, the plastic lumber shall have a negligible
2.1 ASTM Standards:
creep or elastic strain rate, or both, insofar as these properties
D 618 Practice for Conditioning Plastics and Electrical
would significantly affect the accuracy of the measurements.
Insulating Materials for Testing
1.1.1 This test method details the determination of the linear
D 883 Terminology Relating to Plastics
coefficient of thermal expansion of plastic lumber and plastic
D 4065 Practice for Determining and Reporting Dynamic
lumber shapes in their “as manufactured” form.As such, this is
Mechanical Properties of Plastics
a test method for evaluating the properties of plastic lumber or
D 5033 Practice for the Development of Standards Relating
shapes as a product and not a material property test method.
to the Proper Use of Recycled Plastics
1.2 The thermal expansion of plastic lumber and shapes is
E 831 Test Method for Linear Thermal Expansion of Solid
composed of a reversible component on which may be super-
Materials by Thermomechanical Analysis
imposed changes in length due to changes in moisture content,
3. Terminology
curing, loss of plasticizer or solvents, release of stresses, phase
changes, voids, inclusions, and other factors. This test method 3.1 Definitions:
is intended to determine the coefficient of linear thermal
3.1.1 plastic lumber, n—a manufactured product composed
expansion under the exclusion of non-linear factors as far as
of more than 50 weight percent resin, in which the product
possible. In general, it will not be possible to exclude the effect generally is rectangular in cross-section and typically supplied
ofthesefactorscompletely.Forthisreason,thetestmethodcan
in board and dimensional lumber sizes, may be filled or
be expected to give a reasonable approximation but not unfilled, and may be composed of single or multiple resin
necessarily precise determination of the linear coefficient of
blends.
thermal expansion. 3.1.2 plastic lumber shape, n—a plastic lumber product
1.3 Plastic lumber and plastic lumber shapes are currently
which is generally not rectangular in cross-section.
made predominately with recycled plastics where the product 3.1.3 resin, n—a solid or pseudosolid organic material often
is non-homogeneous in the cross-section. However, this test
of high molecular weight, which exhibits a tendency to flow
method may also be applicable to similar manufactured plastic when subjected to stress, usually has a softening or melting
products made from virgin resins or other plastic composite
range, and usually fractures conchoidally. (D 883)
materials. 3.1.3.1 Discussion—In a broad sense, the term is used to
1.4 The values stated in inch-pound units are to be regarded
designate any polymer that is a basic material for plastics.
as the standard. The SI units given in parentheses are for (1982)
information only.
3.2 Additional definitions of terms applying to this test
1.5 This standard does not purport to address all of the method appear in Terminology D 883 and Practice D 5033.
safety concerns, if any, associated with its use. It is the
Annual Book of ASTM Standards, Vol 08.01.
1 3
ThistestmethodisunderthejurisdictionofASTMCommitteeD-20onPlastics Annual Book of ASTM Standards, Vol 08.02.
and is the direct responsibility of Subcommittee D20.20 on Plastic Products. Annual Book of ASTM Standards, Vol 08.03.
Current edition approved Nov. 10, 1998. Published February 1999. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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.
D6341–98
4. Summary of Test Method or test series, the same caliper shall be used for all measure-
ments.The calipers shall be kept and used at room temperature
4.1 This test method is intended to provide a means of
(73.4°F (23°C)).
determining the coefficient of linear thermal expansion of
6.3 Thermometer or Thermocouple, capable of an accuracy
plasticlumberandplasticlumbershapeswhichmayormaynot
of 6 0.2°F (6 0.1°C) when measuring the temperature of the
contain inclusions and voids. This test method is a product test
conditioning chamber.
method, and not a materials test method. Furthermore, this test
method is not designed to provide more than two significant
7. Test Specimen
figures of accuracy in the result. The test method involves
7.1 Test specimens for determining thermal expansion of
using solid, full cross-sectioned members (see Note 2), as
plastic lumber and plastic lumber shapes shall be cut from the
manufactured,ofapproximately12in.(300mm)inlength.The
“as manufactured” profile. Great care shall be taken in cutting
low thermal conductivity of these materials make dynamic
and machining the ends so that smooth, flat, parallel surfaces
temperature variations in a reasonable length of time imprac-
and sharp, clean edges result and are parallel to within 1/300 of
tical. Therefore, measurements are taken on each sample after
the specimen length perpendicular to the long axis of the
conditioning 48 h or more at three discrete temperatures, –30,
specimen. Plastic lumber is generally non-uniform through the
73.4, and 140°F, 6 3.6°F (–34.4, 23, and 60°C, 6 2°C), no
cross-section; machining operations other than those required
more than 1 min after removal from the temperature chamber.
to provide flat, parallel ends shall not be carried out. A line
The measuring device used is a caliper capable of measuring to
parallel to the length shall be marked with an indelible ink
the nearest 0.001 in. (0.025 mm), and is utilized at ambient
marker on an uncut surface along the full length of the
temperature.
specimen.Lengthmeasurementsofthesamplearetobecarried
NOTE 2—Hollow cross-section products may be evaluated with this test
out on the surfaces adjacent to the drawn lines (on the cut
method provided it can be shown that negligible dimensional changes
faces) at each end of the specimen, at a location very near the
occur in the prescribed measurement time interval.
ends of the line.
7.2 Thestandardtestspecimenshallbeintheformofaright
5. Significance and Use
cylinder or prism whose length is a minimum of 12 6 0.25 in.
5.1 The coefficient of linear thermal expansion, a, between
(300 mm 6 6.4 mm) (see Note 3).
temperatures T and T foraspecimenwhoselengthis L atthe
1 2 0
reference temperature, is given by the following equation: NOTE 3—This test method may be utilized to determine the linear
coefficient of thermal expansion for other sample directions (that is, width
1 L – L 1 DL
2 1
or thickness) if desired. However, the accuracy of the measurements will
a5 · 5 · (1)
L T – T L DT
0 2 1 0
be significantly reduced due to the generally smaller linear dimension.
Where L and L are the specimen lengths at temperatures T
1 2 1
8. Conditioning
and T , respectively. a is, therefore, obtained by dividing the
linear expansion per unit length by the change in temperature.
8.1 Conditioning—Condition the test specimens at –30,
5.2 The nature of most plastics and the construction appli-
73.4, and 140°F 6 3.6°F (–34.4, 23, and 60°C 6 2°C) and 50
cations for which plastic lumber and plastic lumber shapes are 6 5 % relative humidity for not less than 48 h at each
used, make –30 to 140°F (–34.4 to 60°C) a practical tempera-
temperature prior to testing in accordance with ProcedureAof
ture range for linear thermal expansion measurements. Where Practice D 618, unless otherwise specified by the customer or
testingoutsideofthistemperaturerangeorwhenlinearthermal
product specification. In cases of disagreement, the tolerances
expansion characteristics of a particular plastic are not known shall be 6 1.8°F (6 1°C) and 6 2 % relative humidity.
through this temperature range, particular attention shall be
8.2 Test Conditions—Conduct measurements in the stan-
paid to the factors mentioned in 1.2 and special preliminary dard laboratory atmosphere of 73.4 6 3.6°F (23 6 2°C) and 50
investigations by thermo-mechanical analysis, such as that
6 5 % relative humidity, within 1 min or less after removal
prescribed in Practice D 4065 for the location of transition from the conditioning environment unless otherwise specified
temperatures, may be required to avoid excessive error. If such
by the customer or product specification. In cases of disagree-
a transition point is located, a separate coefficient
...
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