ASTM D6341-98(2005)
(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)
SIGNIFICANCE AND USE
The coefficient of linear thermal expansion, α, between temperatures T1 and T2 for a specimen whose length is L0 at the reference temperature, is given by the following equation:
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 superimposed 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 brackets are for information only.
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: D6341 – 98 (Reapproved 2005)
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 D6341; 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 1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This test method covers the determination of the coef-
responsibility of the user of this standard to establish appro-
ficient of linear thermal expansion for plastic lumber and
priate safety and health practices and determine the applica-
plastic lumber shapes to two significant figures. The determi-
bility of regulatory limitations prior to use.
nation is made by taking measurements with a caliper at three
discrete temperatures. At the test temperatures and under the
NOTE 1—There is no similar or equivalent ISO standard.
stresses imposed, the plastic lumber shall have a negligible
2. Referenced Documents
creep or elastic strain rate, or both, insofar as these properties
would significantly affect the accuracy of the measurements.
2.1 ASTM Standards:
1.1.1 Thistestmethoddetailsthedeterminationofthelinear
D618 Practice for Conditioning Plastics for Testing
coefficient of thermal expansion of plastic lumber and plastic
D883 Terminology Relating to Plastics
lumber shapes in their “as manufactured” form.As such, this is
D4065 Practice for Plastics: Dynamic Mechanical Proper-
a test method for evaluating the properties of plastic lumber or
ties: Determination and Report of Procedures
shapes as a product and not a material property test method.
D5033 Guide for Development of ASTM Standards Relat-
1.2 The thermal expansion of plastic lumber and shapes is
ing to Recycling and Use of Recycled Plastics
composed of a reversible component on which may be super-
E831 Test Method for Linear Thermal Expansion of Solid
imposed changes in length due to changes in moisture content,
Materials by Thermomechanical Analysis
curing, loss of plasticizer or solvents, release of stresses, phase
3. Terminology
changes, voids, inclusions, and other factors. This test method
is intended to determine the coefficient of linear thermal 3.1 Definitions:
expansion under the exclusion of non-linear factors as far as
3.1.1 plastic lumber, n—a manufactured product composed
possible. In general, it will not be possible to exclude the effect of more than 50 weight percent resin, in which the product
ofthesefactorscompletely.Forthisreason,thetestmethodcan
generally is rectangular in cross-section and typically supplied
be expected to give a reasonable approximation but not in board and dimensional lumber sizes, may be filled or
necessarily precise determination of the linear coefficient of
unfilled, and may be composed of single or multiple resin
thermal expansion. blends.
1.3 Plastic lumber and plastic lumber shapes are currently
3.1.2 plastic lumber shape, n—a plastic lumber product
made predominately with recycled plastics where the product which is generally not rectangular in cross-section.
is non-homogeneous in the cross-section. However, this test
3.1.3 resin, n—a solid or pseudosolid organic material often
method may also be applicable to similar manufactured plastic of high molecular weight, which exhibits a tendency to flow
products made from virgin resins or other plastic composite
when subjected to stress, usually has a softening or melting
materials. range, and usually fractures conchoidally. (D883)
1.4 The values stated in inch-pound units are to be regarded
as the standard. The SI units given in brackets are for
information only.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction ofASTM Committee D20 on Plastics contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and is the direct responsibility of Subcommittee D20.20 on Plastic Products. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2005. Published February 2006. Originally the ASTM website.
approved in 1998. Last previous edition approved in 1998 as D6341 - 98. DOI: Withdrawn. The last approved version of this historical standard is referenced
10.1520/D6341-98R05. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6341 – 98 (2005)
3.1.3.1 Discussion—In a broad sense, the term is used to 6. Apparatus
designate any polymer that is a basic material for plastics.
6.1 Conditioning Chamber, capable of conditioning test
(1982)
specimens at temperatures in the range of –30 to 140°F, 6
3.2 Additional definitions of terms applying to this test
1.8°F [–34.4 to 60°C, 6 1°C], at humidity levels of 50 65%.
method appear in Terminology D883 and Practice D5033.
6.2 Caliper, capable of measuring the length of the speci-
men with an accuracy of 0.001 in. [0.025 mm]. For a given test
4. Summary of Test Method
or test series, the same caliper shall be used for all measure-
4.1 This test method is intended to provide a means of
ments.The calipers shall be kept and used at room temperature
determining the coefficient of linear thermal expansion of
(73.4°F [23°C]).
plasticlumberandplasticlumbershapeswhichmayormaynot
6.3 Thermometer or Thermocouple, capable of an accuracy
contain inclusions and voids. This test method is a product test
of 60.2°F [60.1°C] when measuring the temperature of the
method, and not a materials test method. Furthermore, this test
conditioning chamber.
method is not designed to provide more than two significant
figures of accuracy in the result. The test method involves
7. Test Specimen
using solid, full cross-sectioned members (see Note 2), as
7.1 Test specimens for determining thermal expansion of
manufactured,ofapproximately12in.[300mm]inlength.The
plastic lumber and plastic lumber shapes shall be cut from the
low thermal conductivity of these materials make dynamic
“as manufactured” profile. Great care shall be taken in cutting
temperature variations in a reasonable length of time imprac-
and machining the ends so that smooth, flat, parallel surfaces
tical. Therefore, measurements are taken on each sample after
and sharp, clean edges result and are parallel to within ⁄300 of
conditioning 48 h or more at three discrete temperatures, –30,
the specimen length perpendicular to the long axis of the
73.4, and 140°F, 6 3.6°F [–34.4, 23, and 60°C, 6 2°C], no
specimen. Plastic lumber is generally non-uniform through the
more than 1 min after removal from the temperature chamber.
cross-section; machining operations other than those required
The measuring device used is a caliper capable of measuring to
to provide flat, parallel ends shall not be carried out. A line
the nearest 0.001 in. [0.025 mm], and is utilized at ambient
parallel to the length shall be marked with an indelible ink
temperature.
marker on an uncut surface along the full length of the
NOTE 2—Hollow cross-section products may be evaluated with this test
specimen.Lengthmeasurementsofthesamplearetobecarried
method provided it can be shown that negligible dimensional changes
out on the surfaces adjacent to the drawn lines (on the cut
occur in the prescribed measurement time interval.
faces) at each end of the specimen, at a location very near the
ends of the line.
5. Significance and Use
7.2 Thestandardtestspecimenshallbeintheformofaright
5.1 The coefficient of linear thermal expansion, a, between
cylinder or prism whose length is a minimum of 12 6 0.25 in.
temperatures T and T foraspecimenwhoselengthis L atthe
1 2 0
[300 6 6.4 mm] (see Note 3).
reference temperature, is given by the following equation:
1 L – L 1 DL NOTE 3—This test method may be utilized to determine the linear
2 1
a5 · 5 · (1)
coefficient of thermal expansion for other sample directions (that is, width
L T – T L DT
0 2 1 0
or thickness) if desired. However, the accuracy of the measurements will
Where L and L are the specimen lengths at temperatures T
1 2 1 be significantly reduced due to the generally smaller linear dimension.
and T , respectively. a is, therefore, obtained by dividing the
linear expansion per unit length by the change in temperature. 8. Conditioning
5.2 The nature of most plastics and the construction appli-
8.1 Conditioning—Condition the test specimens at –30,
cations for which plastic lumber and plastic lumber shapes are
73.4, and 140°F 6 3.6°F [–34.4, 23, and 60°C 6 2°C] and 50
used, make –30 to 140°F [–34.4 to 60°C] a practical tempera-
6 5 % relative humidity for not less than 48 h at each
ture range for linear thermal expansion measurements. Where
temperature prior to testing in accordance with ProcedureAof
testingoutsideofthistemperaturerangeorwhenlinearthermal
Practice D618, unless otherwise specified by the customer or
expansion characteristics of a particular plastic are not known
product specification. In cases of disagreement, the tolerances
through this temperature range, particular attention shall be
shall be 61.8°F [61°C] and 62 % relative humidity.
paid to the factors mentioned in 1.2 and special preliminary
8.2 Test Conditions—Conduct measurements in the stan-
investigations by thermo-mechanic
...
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