Standard Test Method for Density of High-Modulus Fibers

SCOPE
1.1 This method covers the determination of the density of high-modulus fibers and is applicable to both continuous and discontinuous fibers.  
1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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. For hazard statements see Section 7.

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Publication Date
09-Oct-1999
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ASTM D3800-99 - Standard Test Method for Density of High-Modulus Fibers
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation: D 3800 – 99
Standard Test Method for
Density of High-Modulus Fibers
This standard is issued under the fixed designation D 3800; 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 (ϵ) 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 Materials in Computerized Material Property Databases
1.1 This test method covers the determination of the density
3. Terminology
ofhigh-modulusfibersandisapplicabletobothcontinuousand
3.1 Definitions—Terminology D 3878D 3878 defines terms
discontinuous fibers.
relating to composite materials. Terminology E 12E12 defines
1.2 This standard may involve hazardous materials, opera-
terms relating to density. Practice E 177E 177 defines terms
tions, and equipment. This standard does not purport to
relating to statistics. In the event of a conflict between terms,
address all of the safety concerns, if any, associated with its
Terminology D 3878D 3878 shall have precedence over other
use. It is the responsibility of the user of this standard to
standards.
establish appropriate safety and health practices and deter-
3.2 Symbols:
mine the applicability of regulatory limitations prior to use.
See Section 9 for additional information.
1.3 The values stated in SI units are to be regarded as
ρ = density of standard
s
standard.
ρ = density of liquid
l
ρ = density of fiber
f
2. Referenced Documents
ρ = density of the measured fiber containing sizing
mf
2.1 ASTM Standards:
ρ = density of the measured liquid containing sur-
ml
D 891 Test Methods for Specific Gravity, Apparent, of
factant
Liquid Industrial Chemicals ρ = density of surfactant
sur
D 1505 Test Method for Density of Plastics by the Density- ρ = density of sizing
sz
Gradient Technique ρ = density of water
w
s = standard deviation
D 3878 Terminology of High-Modulus Reinforcing Fibers
M = weight of suspension wire in air
and Their Composites 1
M = weight of suspension wire in liquid (to immer-
D 5229/D 5229M Test Method for Moisture Absorption
sion point)
Properties and Equilibrium Conditioning of Polymer Ma-
4 M = weight of suspension wire plus item whose
trix Composite Materials
density is to be determined (in air)
D 6308 Guide for Identification of Composite Materials in
M = weight of suspension wire plus item whose
Computerized Material Property Databases
density is to be determined (in liquid)
E12 Terminology Relating to Density and Specific Gravity
M –M = weight of item for density to be determined in
3 1
of Solids, Liquids, and Gases
air
E 177 Practice for Use of the Terms Precision and Bias in
M –M = weight of item for density to be determined in
6 4 2
ASTM Test Methods
liquid
E 1471 Guide for Identification of Fibers, Fillers, and Core
4. Summary of Test Method
4.1 General—Usingrandomselectiontechniques,asuitable
This test method is under the jurisdiction of ASTM Committee D-30 on
Composite Materials and is the direct responsibility of Subcommittee D30.03 on
size sample of high-modulus fiber can be tested by any of the
Constituent/Precursor Properties.
three procedures described in this test method. Procedure A
Current edition approved Oct. 10, 1999. Published February 2000. Originally
ϵ1 using water with a surfactant as the liquid medium is preferred
published as D 3000 – 79. Last previous edition D 3800 – 79 (1990) .
due to environmental and safety considerations. The other
Annual Book of ASTM Standards, Vol 15.05.
Annual Book of ASTM Standards, Vol 08.01.
methods shall not be used if Procedure A is adequate. Interim
Annual Book of ASTM Standards, Vol 15.03.
use of Procedures B or C is allowed while a comparison is
Discontinued; see 1995 Annual Book of ASTM Standards, Vol 15.05. Replaced
made to results using Procedure A.
by Terminology E 1547.
Annual Book of ASTM Standards, Vol 14.02. 4.2 Procedure A—Buoyancy (Archimedes) Method:
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.
Please contact ASTM International (www.astm.org) for the latest information.
D3800–99
4.2.1 The sample is weighed in air and weighed in a liquid 6.1.5 Effect of Surfactant Density—The addition of a sur-
that will thoroughly wet the sample and is of a lower density. factant to a liquid may produce bias if not considered. The
4.2.2 The difference in weight of the sample in the two effect may be shown by the following equation:
media is the buoyancy force. This force is converted to sample
~100 – x! r 1 x~r !
l sur
r 5 (2)
volume by dividing it by the liquid density. The sample weight
ml
in air divided by the sample volume equals the sample density.
where
4.3 Procedure B—Sink-Float Technique:
x = mass of surfactant as a percentage of total mass of the
4.3.1 The sample is placed in a container containing a liquid
measured liquid.
that will thoroughly wet the sample and is of a lower density.
6.2 (Method A):
A liquid of higher density than the sample and miscible with
6.2.1 Immersion Point—The distance the sample is lowered
the first liquid is then added slowly to the container under
into the liquid and the overall liquid level should be the same
constant gentle mixing until the sample is suspended in the
throughout determinations for Procedure A. This may be done
mixture.
by putting a line for the desired liquid level on the outside of
4.3.2 The density of the resulting mixed liquid is deter-
the container. The sample size should be within a few grams
mined using either a hydrometer or a pycnometer. The density
from one sample to another.
of the sample is equal to the density of the liquid in which the
sample is suspended.
7. Apparatus
4.4 Procedure C—For an alternative method, which may be
7.1 General:
used, see Test Method D 1505D 1505.
7.1.1 Thermometer, capable of reading the test temperature
5. Significance and Use
during the test to 0.1°C.
5.1 Fiberdensityisusefulintheevaluationofnewmaterials 7.1.2 Agitator—Stirrer or mixing propeller capable of
attheresearchanddevelopmentlevelandisoneofthematerial
slowly agitating solution without test interference.
properties normally given in fiber specifications. 7.2 Procedure A:
5.2 Fiber density is used to determine fiber strength and
7.2.1 Balance, analytical, capable of weighing to 0.0001 g,
modulus both of a fiber bundle and an individual filament. adapted for suspension weighing.
These properties are based on load or modulus slope over an
7.2.2 Balance Stand,dependingonthetypeofbalanceused;
effective area. Fiber density may be used with lineal mass of two recommended stands are shown in Figs. 1 and 2.
the fiber to give an approximation of effective tow area. Tow
7.2.3 Laboratory Jack, heavy-duty precision.
area divided by the average number of filaments in a tow gives 7.2.4 Suspension Wire, nickel or stainless steel, approxi-
an approximation of the effective area of an individual fila-
mately0.4mmindiameter,cutandshapedtomatchthesystem
ment. used.
5.3 Fiber density is used as a constituent property when
7.2.5 Vacuum Desiccator (with Pump)—An airtight con-
determining reinforcement volume and void volume based on tainerinwhichalowvacuum(lessthan75kPa[22in.Hg])can
reinforcement mass and laminate density.
be maintained.
7.2.6 Density Standard—A solid piece of borosilicate glass
6. Interferences
(density approximately 2.2 g/mL) of known density to four
6.1 General (All Methods):
significant figures as determined by water immersion. ANIST
6.1.1 Temperature—The temperature of the liquid shall
standard of this type (SRM 1825) is recommended.
remain constant within a tolerance of6 1°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
7.3.2 Immersion Liquids—See Notes 1 and 2. One liquid
density of the material.
should have a density less than the fiber, and the other greater,
~100 – x! r 1 x~r ! so when mixed they have the same density as the fiber. Two
f sz
r 5 (1)
mf
where ANo. 19 “Pyrex” glass stopper with a 3.175-mm diameter hole bored through
the top for suspension purposes has proved satisfactory.
x = mass of sizing as a percentage of the total mass of the
One suitable surfactant to use with water is Triton X manufactured by Rohm
measured fiber.
and Haas, Philadelphia, PA.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D3800–99
FIG. 1 Density Apparatus (Alternative)
carefully, and weigh the filled bottle again to the nearest 0.2 mg. Empty
suitable liquids are trichloroethylene and dibromomethane
the pycnometer, dry, and then fill and weigh with the other liquid in the
(having densities of 1.464 and 2.477 g/mL). Both of these
same manner as was done with the water. Calculate the specific gravity at
liquids pose hazards (see Section 8).
23°C of the liquid, ρ, as follows:
f
7.3.3 Hydrometer, capable of reading liquid density.
r 5 ~b – e!/~w – e! (3)
7.4 Procedure C—Use the apparatus described in Test l
Method D 1505D 1505.
where:
e = apparent weight of empty pycnometer,
NOTE 1—Standard deionized or distilled water need not be measured,
9 w = apparent weight of pycnometer filled with water at 23°C, and
but can be taken as a value from standard tables. For the determination
b = apparent weight of pycnometer filled with liquid at 23°C.
of the specific gravity of the liquid, the use of a standard plummet of
If a constant-temperature bath is available, a pycnometer without a
known volume (Note 3) or Test Method A, C, or D of Test Methods
thermometer may be used.
D 891D 891, using the modifications required to give specific gravity at
NOTE 2—One standard, which has been found satisfactory for this
23°C is recommended. One suggested procedure is the following: If a
purpose, is the Reimann Thermometer Plummet. These are normally
constant temperature water bath is not available, determine the weight of
calibrated for measurements at temperatures other than 23/23°C, so that
the clean, dry pycnometer with the thermometer to the nearest 0.1 mg on
recalibration is necessary for the purpose of these test methods. Calibra-
an analytical balance. Fill the pycnometer with water cooler than 23°C.
tions at intervals of one week are recommended.
Insert the thermometer stopper causing excess water to be expelled
through the side arm. Permit the filled bottle to warm in air until the
8. Reagents
thermometer reads 23°C. Remove the drop of water at the tip of the side
arm with a bit of filter paper, taking care not to draw any liquid from
8.1 Purity of Reagents—As a minimum, a technical grade
within the capillary. Place the cap over the side arm, wipe the outside
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
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D3800–99
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 D 5229/D 5229MD 5229/D 5229M may
by the International Agency for Research on Cancer in Group
be used to determine equilibrium dryness of a fiber. In general,
2D as a “cancer suspec
...

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