ASTM C1351M-96

Standard Test Method for Measurement of Viscosity of Glass Between 10⁴ Pa-s and 10⁸ Pa-s by Viscous Compression of a Solid Right Cylinder [Metric]

SCOPE
1.1 This test method covers the determination of the viscosity of glass from 104 Pa·s to 108 Pa·s by measuring the rate of viscous compression of a small, solid cylinder.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 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.

General Information

• Status: Historical
• Publication Date: 09-Oct-1996
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.04 - Physical and Mechanical Properties

Relations

• Replaced By: ASTM C1351M-96(2002) - Standard Test Method for Measurement of Viscosity of Glass Between 10⁴ Pa-s and 10⁸ Pa-s by Viscous Compression of a Solid Right Cylinder [Metric]
• Effective Date: 10-Oct-1996
• Referred By: ASTM C1350M-96(2019) - Standard Test Method for Measurement of Viscosity of Glass Between Softening Point and Annealing Range (Approximately 10⁸ Pa·s to Approximately 10¹³ Pa·s) by Beam Bending (Metric)
• Effective Date: 10-Oct-1996

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 1351M – 96
METRIC
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Measurement of Viscosity of Glass Between 10 Pa·s and
10 Pa·s by Viscous Compression of a Solid Right Cylinder
[Metric]
This standard is issued under the fixed designation C 1351M; 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
where:
h5 viscosity, Pa·s,
1.1 This test method covers the determination of the viscos-
4 8
M 5 applied load, g,
ity of glass from 10 Pa·s to 10 Pa·s by measuring the rate of
2 g 5 acceleration due to gravity, 980 cm/s ,
viscous compression of a small, solid cylinder.
t 5 time, s,
1.2 The values stated in SI units are to be regarded as the
V 5 specimen volume, cm ,
standard.
h 5 specimen thickness at time t, cm,
1.3 This standard does not purport to address all of the
dh/dt 5 compression rate, cm/s, and
safety concerns, if any, associated with its use. It is the
a5 glass mean coefficient of thermal expansion, 25°C
responsibility of the user of this standard to establish appro-
to the measurement temperature, T, m/m/°C. See
priate safety and health practices and determine the applica-
Note 1.
bility of regulatory limitations prior to use.
NOTE 1—The term (1 + aT) corrects for the specimen dimensional
2. Referenced Documents
changes due to thermal expansion. For low thermal expansion glasses, it
−6
can be ignored. However, for a glass with an a of 20 3 10 /°C at a
2.1 ASTM Standards:
measurement temperature of 1000°C, this term produces a correction of
C 338 Test Method for the Softening Point of Glass
2 %. Only an estimate of a is necessary since the correction is small. Use
C 965 Practice for Measuring Viscosity of Glass Above the
twice the room temperature coefficient if data are unavailable.
Softening Point
4. Significance and Use
C 1350M Test Method for Measurement of Viscosity of
Glass between the Softening Point and the Annealing
4.1 This test method is well suited for measuring the
8 13
Range (Approximately 10 Pa·s to 10 Pa·s) by Beam
viscosity of glasses between the range within which rotational
Bending
viscometry (see Practice C 965) is useful and the range within
which beam bending viscometry is useful (see Test Method
3. Terminology
C 1350M). It can be used to determine the viscosity/
3.1 parallel plate viscometer—a device used to determine
temperature curve in the region near the softening point (see
4 8
the viscosity of glass from approximately 10 Pa·s to 10 Pa·s
Test Method C 338). This test method is useful for providing
by measuring the rate of change in thickness of a cylindrical
information related to the behavior of glass as it is formed into
specimen between parallel plates moving perpendicular to their
an object of commerce, and in research and development.
common central axis. The equation for calculating viscosity by
5. Apparatus
the parallel plate method is:
5.1 The apparatus shall consist of a furnace, a means of
Mgh
h5 2p (1)
controlling and measuring its temperature and heating rate,
30V dh/dt 2ph 1 V 11aT
~ !~ !~ !
specimen holders and loading rod, and a means of measuring
the rate of viscous compression of the glass specimen.
5.2 Furnace:
5.2.1 The furnace shall be electrically heated by resistance
This test method is under the jurisdiction of ASTM Committee C-14 on Glass
elements. The dimensions and details of the furnace construc-
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
tion are not critical; its cross-section can be circular of 75 mm
Physical and Mechanical Properties.
Current edition approved Oct. 10, 1996. Published December 1996.
(’3 in.) diameter or square of sides of 75 mm. The furnace
Fontana, E. H., “A Versatile Parallel-Plate Viscometer For Glass Viscosity
should have a constant temperature zone that covers the
Measurements to 1000°C”, Bulletin of the American Ceramic Society, Vol 49, No.
specimen geometry, including the compression range. Differ-
6, 1970, pp. 594–597.
Annual Book of ASTM Standards, Vol 15.02. ences in temperature greater than 2°C within the constant
C 1351M
temperature zone are unacceptable. plate (see Note 2), 6 mm (; ⁄4 in.) thick by diameter of the
5.3 Temperature Measuring and Indicating Instruments: support stand. A movable plate, 6 mm thick by 44 mm
5.3.1 For the measurement of temperature, there shall be minimum diameter is placed parallel and concentrically above
provided a calibrated Type K, R, or S thermocouple. The the fixed plate. (See parallel plates in Fig. 1.) Attached to the
thermocouple shall be housed in a double-bore alumina tube top center of the movable plate in a shrink fit configuration is
with its junction placed within 5 mm of the specimen near the a 9-mm (; ⁄8-in.) diameter centerless-ground alumina rod of
axis of the furnace. The thermocouple shall be referenced to length sufficient to reach approximately 150 mm (6 in.) beyond
0°C by means of an ice bath, and its emf measured with a the top of the furnace or its supporting structure, or both. This
calibrated potentiometer that can be read with a sensitivity assembly provides a means for loading the specimen during
equivalent to6 0.1°C and an accuracy of 60.5°C. Precautions measurement. Bushings attached to the external frame guide
shall be taken to ensure that the ice bath is maintained at 0°C the shaft with a minimum amount of friction.
throughout the test. Alternately, the output of the thermocouple
NOTE 2—Alumina and vitreous silica are suitable materials for the
can be measured on a calibrated, direct reading meter (elec-
assembly components, as are noble or low expansion metals used in pairs.
tronic thermometer) that can be read with a sensitivity of
The user must observe temperature limitations for these alternate materi-
60.1°C and an accuracy of 60.5°C. See Note 3 for tempera-
als.
ture lag-lead corrections.
5.6 Extensometer for Measuring Thickness Change:
5.4 Furnace Control:
5.6.1 The means of observing the rate of thickness change
5.4.1 Suitable means shall be provided for maintaining the
of the specimen should allow reliable reading of total change of
furnace at a fixed control point and for controlling the heating
at least 6 mm. The extensometer shall permit direct reading of
and cooling rates. Commercially available programming
0.010 mm and estimates of 0.001 mm. Its accuracy shall be
equipment provides excellent control. A variable transformer
such that the error of indication will not exceed 62 % for any
with manual control is an inexpensive, but less adequate means
measured translation. This will limit the minimum translation
of accomplishing the required control.
that may be used in calculation. A linearly variable differential
5.5 Specimen Holder and Loading Rod:
transformer (LVDT) is suitable for this purpose, as is any other
5.5.1 A typical configuration is presented in Fig. 1. Posi-
device (for example, optical or capacitative), provided that
tioned horizontally on top of the support stand is a stationary
length changes are reliably measured as specified.
5.7 Micrometer Calipers:
5.7.1 Micrometer calipers, which can be read to an accuracy
of at least 0.01 mm are required for measuring specimen
dimensions.
6. Preparation of Test Specimen
6.1 Specimens required for this test method are small, right,
circular cylinders. Nominal dimensions are 6 mm (; ⁄4 in.) to
12 mm (; ⁄2 in.) diameter and 3 to 6 m
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