ASTM D3800-99(2004)
(Test Method)Standard Test Method for Density of High-Modulus Fibers
Standard Test Method for Density of High-Modulus Fibers
SIGNIFICANCE AND USE
Fiber density is useful in the evaluation of new materials at the research and development level and is one of the material properties normally given in fiber specifications.
Fiber density is used to determine fiber strength and modulus both of a fiber bundle and an individual filament. These properties are based on load or modulus slope over an effective area. Fiber density may be used with lineal mass of the fiber to give an approximation of effective tow area. Tow area divided by the average number of filaments in a tow gives an approximation of the effective area of an individual filament.
Fiber density is used as a constituent property when determining reinforcement volume and void volume based on reinforcement mass and laminate density.
SCOPE
1.1 This test method covers the determination of the density of high-modulus fibers and is applicable to both continuous and discontinuous fibers.
1.2 The values stated in SI units are to be regarded as standard.
1.3 This standard may involve hazardous materials, operations, and equipment. 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. See Section 9 for additional information.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D3800–99 (Reapproved 2004)
Standard Test Method for
Density of High-Modulus Fibers
This standard is issued under the fixed designation D3800; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3. Terminology
1.1 This test method covers the determination of the density 3.1 Definitions—Terminology D3878 defines terms relating
ofhigh-modulusfibersandisapplicabletobothcontinuousand tocompositematerials.TerminologyE12definestermsrelating
discontinuous fibers. to density. Practice E177 defines terms relating to statistics. In
1.2 The values stated in SI units are to be regarded as theeventofaconflictbetweenterms,TerminologyD3878shall
standard. have precedence over other standards.
1.3 This standard may involve hazardous materials, opera- 3.2 Symbols:
tions, and equipment. This standard does not purport to
address all of the safety concerns, if any, associated with its
r = density of standard
s
use. It is the responsibility of the user of this standard to
r = density of liquid
l
establish appropriate safety and health practices and deter-
r = density of fiber
f
mine the applicability of regulatory limitations prior to use.
r = density of the measured fiber containing sizing
mf
See Section 9 for additional information.
r = density of the measured liquid containing sur-
ml
factant
2. Referenced Documents
r = density of surfactant
sur
2.1 ASTM Standards:
r = density of sizing
sz
D891 Test Methods for Specific Gravity, Apparent, of
r = density of water
w
Liquid Industrial Chemicals
s = standard deviation
D1505 Test Method for Density of Plastics by the Density-
M = weight of suspension wire in air
Gradient Technique
M = weight of suspension wire in liquid (to immer-
D3878 Terminology for Composite Materials sion point)
D5229/D5229M Test Method for Moisture Absorption M = weight of suspension wire plus item whose
density is to be determined (in air)
Properties and Equilibrium Conditioning of Polymer Ma-
M = weight of suspension wire plus item whose
trix Composite Materials
density is to be determined (in liquid)
D6308 Guide for Identification of Composite Materials in
M –M = weight of item for density to be determined in
Computerized Material Property Databases
3 1
air
E12 Terminology Relating to Density and Specific Gravity
M –M = weight of item for density to be determined in
of Solids, Liquids, and Gases 4 2
liquid
E177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
4. Summary of Test Method
E1471 Guide for Identification of Fibers, Fillers, and Core
4.1 General—Usingrandomselectiontechniques,asuitable
Materials in Computerized Material Property Databases
size sample of high-modulus fiber can be tested by any of the
three procedures described in this test method. Procedure A
This test method is under the jurisdiction of ASTM Committee D30 on
using water with a surfactant as the liquid medium is preferred
Composite Materials and is the direct responsibility of Subcommittee D30.03 on
due to environmental and safety considerations. The other
Constituent/Precursor Properties.
methods shall not be used if Procedure A is adequate. Interim
Current edition approved Oct. 1, 2004. Published October 2004. Originally
approved in 1979. Last previous edition approved in 1999 as D3800 – 99. DOI:
use of Procedures B or C is allowed while a comparison is
10.1520/D3800-99R04.
made to results using Procedure A.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.2 Procedure A—Buoyancy (Archimedes) Method:
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Withdrawn.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3800–99 (2004)
4.2.1 The sample is weighed in air and weighed in a liquid
x = mass of sizing as a percentage of the total mass of the
that will thoroughly wet the sample and is of a lower density.
measured fiber.
4.2.2 The difference in weight of the sample in the two
6.1.5 Effect of Surfactant Density—The addition of a sur-
media is the buoyancy force. This force is converted to sample
factant to a liquid may produce bias if not considered. The
volume by dividing it by the liquid density. The sample weight
effect may be shown by the following equation:
in air divided by the sample volume equals the sample density.
~100 – x! r 1 x~r !
l sur
r 5 (2)
4.3 Procedure B—Sink-Float Technique:
ml
4.3.1 The sample is placed in a container containing a liquid
where
that will thoroughly wet the sample and is of a lower density.
x = mass of surfactant as a percentage of total mass of the
A liquid of higher density than the sample and miscible with
measured liquid.
the first liquid is then added slowly to the container under
6.2 (Method A):
constant gentle mixing until the sample is suspended in the
6.2.1 Immersion Point—The distance the sample is lowered
mixture.
into the liquid and the overall liquid level should be the same
4.3.2 The density of the resulting mixed liquid is deter-
throughout determinations for Procedure A. This may be done
mined using either a hydrometer or a pycnometer. The density
by putting a line for the desired liquid level on the outside of
of the sample is equal to the density of the liquid in which the
the container. The sample size should be within a few grams
sample is suspended.
from one sample to another.
4.4 Procedure C—For an alternative method, which may be
used, see Test Method D1505.
7. Apparatus
7.1 General:
5. Significance and Use
7.1.1 Thermometer, capable of reading the test temperature
5.1 Fiberdensityisusefulintheevaluationofnewmaterials
during the test to 0.1°C.
attheresearchanddevelopmentlevelandisoneofthematerial
7.1.2 Agitator—Stirrer or mixing propeller capable of
properties normally given in fiber specifications.
slowly agitating solution without test interference.
5.2 Fiber density is used to determine fiber strength and
7.2 Procedure A:
modulus both of a fiber bundle and an individual filament.
7.2.1 Balance, analytical, capable of weighing to 0.0001 g,
These properties are based on load or modulus slope over an
adapted for suspension weighing.
effective area. Fiber density may be used with lineal mass of
7.2.2 Balance Stand,dependingonthetypeofbalanceused;
the fiber to give an approximation of effective tow area. Tow
two recommended stands are shown in Figs. 1 and 2.
area divided by the average number of filaments in a tow gives
7.2.3 Laboratory Jack, heavy-duty precision.
an approximation of the effective area of an individual fila-
7.2.4 Suspension Wire, nickel or stainless steel, approxi-
ment.
mately0.4mmindiameter,cutandshapedtomatchthesystem
5.3 Fiber density is used as a constituent property when
used.
determining reinforcement volume and void volume based on
7.2.5 Vacuum Desiccator (with Pump)—An airtight con-
reinforcement mass and laminate density.
tainerinwhichalowvacuum(lessthan75kPa[22in.Hg])can
be maintained.
6. Interferences
7.2.6 Density Standard—A solid piece of borosilicate glass
6.1 General (All Methods): (density approximately 2.2 g/mL) of known density to four
6.1.1 Temperature—The temperature of the liquid shall significant figures as determined by water immersion. ANIST
standard of this type (SRM 1825) is recommended.
remain constant within a tolerance of 61°C, since liquid
7.2.7 Vacuum Pump or Aspirator, used to provide vacuum-
density changes with temperature.
to-vacuum desiccator.
6.1.2 Sample Wetting (Entrapped Air)—Since this test
7.2.8 Container, glass or other transparent container resis-
method is very dependent on buoyancy, any entrapped air in
tant to a liquid medium is recommended.
the sample will change the measured density and not give a
7.2.9 Immersion Liquid—The liquid used shall not dissolve
true material density. Ensure visually that the sample does not
or otherwise affect the specimen, but should wet it and have a
contain entrapped air bubbles.
specific gravity less than that of the specimen. The specific
6.1.3 Homogenous Mixture—The density of the liquid shall
gravity of the immersion liquid shall be determined shortly
be uniform, through suitable agitation.
before and after each use.
6.1.4 Removal of Sizing—A bias will exist if sizing is not
7.3 Procedure B:
removed. In this case, the measured fiber density is a combi-
7.3.1 Container, glass or other transparent container resis-
nation of the density of the fiber and the sizing. The following
tant to liquids used is recommended.
equation may be used to calculate the effect of the sizing on the
density of the material.
~100 – x! r 1 x~r !
f sz
r 5 (1)
ANo. 19 “Pyrex” glass stopper with a 3.175-mm diameter hole bored through
mf
the top for suspension purposes has proved satisfactory.
One suitable surfactant to use with water is Triton X manufactured by Rohm
where
and Haas, Philadelphia, PA.
D3800–99 (2004)
FIG. 1 Density Apparatus (Alternative)
of filter paper, taking care not to draw any liquid from within the capillary.
7.3.2 Immersion Liquids—See Notes 1 and 2. One liquid
Place the cap over the side arm, wipe the outside carefully, and weigh the
should have a density less than the fiber, and the other greater,
filled bottle again to the nearest 0.2 mg. Empty the pycnometer, dry, and
so when mixed they have the same density as the fiber. Two
then fill and weigh with the other liquid in the same manner as was done
suitable liquids are trichloroethylene and dibromomethane
with the water. Calculate the specific gravity at 23°C of the liquid, r,as
f
(having densities of 1.464 and 2.477 g/mL). Both of these
follows:
liquids pose hazards (see Section 8).
r 5 ~b – e!/~w – e! (3)
l
7.3.3 Hydrometer, capable of reading liquid density.
7.4 Procedure C—Use the apparatus described in Test where:
e = apparent weight of empty pycnometer,
Method D1505.
w = apparent weight of pycnometer filled with water at 23°C, and
NOTE 1—Standard deionized or distilled water need not be measured,
b = apparent weight of pycnometer filled with liquid at 23°C.
but can be taken as a value from standard tables. For the determination
If a constant-temperature bath is available, a pycnometer without a
of the specific gravity of the liquid, the use of a standard plummet of
thermometer may be used.
known volume (Note 3) orTest MethodA, C, or D ofTest Methods D891,
NOTE 2—One standard, which has been found satisfactory for this
using the modifications required to give specific gravity at 23°C is
purpose, is the Reimann Thermometer Plummet. These are normally
recommended. One suggested procedure is the following: If a constant
calibrated for measurements at temperatures other than 23/23°C, so that
temperature water bath is not available, determine the weight of the clean,
recalibration is necessary for the purpose of these test methods. Calibra-
dry pycnometer with the thermometer to the nearest 0.1 mg on an
tions at intervals of one week are recommended.
analyticalbalance.Fillthepycnometerwithwatercoolerthan23°C.Insert
8. Reagents
the thermometer stopper causing excess water to be expelled through the
side arm. Permit the filled bottle to warm in air until the thermometer
8.1 Purity of Reagents—As a minimum, a technical grade
reads 23°C. Remove the drop of water at the tip of the side arm with a bit
reagent is required to provide accurate results. However, when
resolving disputes or performing subsequent analysis of extract
or residue, a reagent grade reagent shall be used. Unless
One such reference is in CRC Handbook of Chemistry and Physics, CRC Press
Inc., Boca Raton, FL. otherwise indicated, it is intended that the reagents conform to
D3800–99 (2004)
FIG. 2 Density Apparatus (Alternative)
the specifications of the Committee on Analytical Reagents of cals.Asource of useful information is Prudent Practices in the
the American Chemical Society where such specifications are Laboratory: Handling and Disposal of Chemicals, National
available. Academy Press, 1995, 448 pp., ISBN 0-309-05229-7.
8.1.1 Water,H O, (deionized or distilled and degassed), (Warning—In addition to other warnings, consult the appro-
maycontainawettingagentsuchasglycerinorsurfactant.This priate material safety data sheet for each material used,
is the safest reagent found, and recommended for ProcedureA. including reagent materials and test specimen materials, for
specific recommendations on safety and handling.)
NOTE 3—Reagents in 8.1.2-8.1.6 should be used if water is found to be
unsatisfactory to accurately determine the density of the fiber. Other
10. Test Specimen
reagents are listed in order of known hazard or toxicity.
10.1 A minimum of three test specimens shall be tested for
8.1.2 Acetone (2-Propanone),CH CHOCH .
3 3
each sample.
8.1.3 Methanol (Methyl Alcohol),CH OH.
10.2 The test specimen weight shall be a minimum of 0.5 g.
8.1.4 o-dichlorobenzene,CH Cl.(Warning—o-
4 2
dichlorobenzene has been identified as toxic and an irritant.)
11. Calibration and Standardization
8.1.5 Dibromomethane,CH Br.(Warning—As of the ap-
2 2
11.1 All measuring equipment shall have certified calibra-
proval date of this test method, dibromomethane was listed by
tions that are current at the time of use of the equipment. The
the International Agency for Research on Cancer in Group 2C
calibration documentation shall be available for inspection.
as “toxic.”)
8.1.6 Trichloroethylene, CHClCCl.(Warning—Asofthe
12. Conditioning
approval date of this test method, trichloroethylene was listed
12.1 Test Method D5229/D5229M may be used to deter-
by the International Agency for Research on Cancer in Group
mine equilibrium dryness of a fiber. In general, no special
2D as a “cancer suspect agent” and mutagen.)
conditioning is needed for carbon fiber, less than 1 h at 100°C
9. Hazards
is needed for glass fibers, and approximately4hat 100°C is
9.1 This test method should be used only by laboratory needed for aramid fibers.
workers with general training in the safe handling of chemi- 12.2 Condition liquids to a test temperature, typically 23°C.
13. Procedure
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
13.1 Procedure A—Buoyancy (Archimedes) Method):
listed by the American Chemical
...
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