ASTM D2396-94(1999)e1
(Test Method)Standard Test Methods for Powder-Mix Time of Poly(Vinyl Chloride) (PVC) Resins Using a Torque Rheometer
Standard Test Methods for Powder-Mix Time of Poly(Vinyl Chloride) (PVC) Resins Using a Torque Rheometer
SCOPE
1.1 These test methods cover the determination of the powder-mix time of a general-purpose poly(vinyl chloride) (PVC) resin.
1.2 The values stated in SI units are to be regarded as 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. Note 1-There is no ISO standard covering the primary subject of these ASTM test methods.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 2396 – 94 (Reapproved 1999)
Standard Test Methods for
Powder-Mix Time of Poly(Vinyl Chloride) (PVC) Resins
Using a Torque Rheometer
This standard is issued under the fixed designation D 2396; 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.
e NOTE—Inch-pound units were deleted editorially in April 2000.
1. Scope into the resin and the resin granules become dry and free-
flowing. When the mix reaches the dry and free-flowing state,
1.1 These test methods cover the determination of the
its resistance to stirring decreases and the motor torque needed
powder-mix time of a general-purpose poly(vinyl chloride)
to maintain the same rotor speed decreases. By recording the
(PVC) resin.
changes in motor torque with time, it is possible to measure the
1.2 The values stated in SI units are to be regarded as
time required for a resin to absorb a plasticizer.
standard.
4.2 These test methods describe the use of two different
1.3 This standard does not purport to address all of the
mixing heads that can be mounted on a torque rheometer to
safety concerns, if any, associated with its use. It is the
perform this test. Test results obtained with these mixing heads
responsibility of the user of this standard to establish appro-
are compared in Section 14.
priate safety and health practices and determine the applica-
4.2.1 A sigma mixing head is used in Test Method A.
bility of regulatory limitations prior to use.
4.2.2 A planetary mixing head is used in Test Method B.
NOTE 1—There is no ISO standard covering the primary subject of
these ASTM test methods.
5. Significance and Use
5.1 The ability of PVC granules to accept a plasticizer and
2. Referenced Documents
become a dry free-flowing powder is related to the internal
2.1 ASTM Standards:
pore structure of the resin, resin temperature, plasticizer
D 883 Terminology Relating to Plastics
temperature, and the plasticizer used. By choosing an appli-
D 1600 Terminology for Abbreviated Terms Relating to
cable plasticizer and maintaining a uniform temperature for the
Plastics
resin and plasticizer, it is possible to classify resins by how
rapidly they absorb plasticizer. Resin suitability for a specific
3. Terminology
intensive mixing operation can be ascertained using these test
3.1 General:
methods.
3.1.1 Definitions are in accordance with Terminology D 883
and abbreviations are in accordance with Terminology D 1600
6. Interferences
unless otherwise indicated.
6.1 Resin—Each resin has a specific response in accepting a
plasticizer. Differences in powder-mix time between resins can
4. Summary of Test Methods
be observed in the graph in the annex.
4.1 A sample of resin is heated and mixed in a bowl to the
6.2 Plasticizer—Plasticizer viscosity directly affects
test temperature. A measured amount of plasticizer is added to
powder-mix time. Table 1 shows that an increase in diisodecyl
the resin through a dispersing funnel. When the plasticizer is
phthalate viscosity results in an increase in powder-mix time.
added to the resin, the mix becomes wet and an increase in
The data in Table 1 was generated in a single laboratory using
motor torque is needed to maintain the same rotor speed. As the
Test Method A.
mixing continues in the heated bowl, the plasticizer is absorbed
6.3 Temperature—The temperature at which the test is
performed will affect the powder-mix time. A lower test
temperature will have a longer powder-mix time.
These test methods are under the jurisdiction of ASTM Committee D-20 on
Plastics and are the direct responsibility of Subcommittee D20.15 on Thermoplastic
NOTE 2—It is also important to control the temperature of the plasti-
Materials.
cizer added to the resin. The powder-mix time can vary by as much as 3
Current edition approved June 15, 1994. Published August 1994. Originally
published as D 2396 – 69. Last previous edition D 2396 – 88.
Annual Book of ASTM Standards, Vol 08.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 2396 – 94 (1999)
TABLE 1 Powder-Mix Time of ASTM No. 1 Resin
7.11 Spatula.
DIDP Viscosity, Bowl Mean 7.12 Viscometer, Brookfield RVF, or equivalent.
Standard Number of
cP Temperature, Powder-Mix
Deviation Samples
A B
(millipascals-s) °C Time, s
8. Materials
111 85 435 . 2
8.1 Poly(Vinyl Chloride) (PVC) Resin.
128 85 461 6.9 5
147 85 479 . 2
8.2 Diisodecyl Phthalate Plasticizer.
A 6
Viscosity was measured using a Brookfield RVF Viscometer, No. 1 spindle, 20 8.3 Clay.
r/min, at 23°C.
B
The bowl temperature was measured at the thermocouple well.
9. Safety Precautions
9.1 Take care not to exceed the manufacturer’s recom-
s for each degree Farenheit difference in plasticizer temperature, as seen
mended damping limit on the sigma mixer because of the
in the graph in the annex.
danger of bending the blades.
6.4 Equipment—Differences between equipment can result
9.2 Stop the mixer before cleaning the bowl and blades.
in differences in powder-mix times. To equate equipment, it is
suggested that a specific powder-mix time be chosen and that
10. Preparation of Torque Rheometer
the bowl temperature be adjusted to obtain the same time for all
10.1 Electronic Plasti-Corder Torque Rheometer:
equipment. Table 2 shows the results from three laboratories
10.1.1 Adjust the torque rheometer so that the strip chart
using this technique to equate to a powder-mix time for ASTM
torque range reads 200 m-g at full scale.
No. 1 resin using Test Method A to the value set by Laboratory
10.1.2 Set chart speed to 10 mm/min.
1.
10.1.3 Place pen on chart.
6.5 Rotor Speed—Observed with the planetary mixing head
10.1.4 Connect the stock temperature measuring thermo-
(see Test Method B) was a decrease in dry time when the rotor
couple to the recorder and start the recorder.
speed had been increased: 60 r/min @ 82°C using DIDP = dry
10.2 PL-2000 Computerized Torque Rheometer—Program
time of 868 s; and 100 r/min @ 82°C using DIDP = dry time
the PL-2000 Plasti-Corder for the test conditions of:
of 628 s.
Order: (Run information)
Operator: (Name)
7. Apparatus
Date: (Current date)
7.1 Torque Rheometer.
PL-Type: 2000
Mixer Type: Planetary
7.2 Sigma Mixer 650-mL, or equivalent, and the disper-
Sample: PVC (source)
sion trough shown in Fig. 1 for plasticizer distribution. (For
Plasticizer: DIDP (source)
Test Method A.)
Mixer Temperature: 88°C
Speed: 100 r/min
7.3 Planetary Mixer, and the dispersion funnel shown in
Meas. Range: 500 mg
Fig. 2 for plasticizer distribution. (For Test Method B.)
Zero Suppr: 0 %
7.4 Balance, 0.1-g sensitivity.
Damping: 1 s
Test Time: 20 min
7.5 Container, 0.95 L size.
Sample Weight: 400.00 g
7.6 Beaker, 400-mL.
Plasticizer Weight: 200.00 g
7.7 Funnel, for use with planetary mixer (see Test Method
NOTE 3—When using equipment other than C. W. Brabender, refer to
B).
the manufacturer’s suggested settings for their equipment.
7.8 Ruler, with metric scale.
7.9 Paint Brush, 25.4 mm width.
11. Procedures
7.10 Thermometer, range of 40 to 100°C with 0.2°C divi-
11.1 Test Method A (Sigma Mixer):
sions.
11.1.1 Attach the 650-mL oil (or electric) Sigma Mixer to
the torque rheometer.
11.1.2 Adjust the mixer-jacket temperature to 88 6 1°C as
The C. W. Brabender PL 2000 Computerized Plasticorder or Electronic
measured at the thermocouple well.
Plasticorder, a registered trademark of C. W. Brabender Instruments, Inc., 50 E.
Wesley Street, South Hackensack, NJ 07606, or System 903, a registered trademark 11.1.3 Set the mixer speed to 60 6 1 r/min.
of Haake Buchler Instruments, Inc., 244 Saddle River Road, Saddle Brook, NJ
11.1.4 Weigh the resin and clay of the following formulation
07662, or equivalents, have been found suitable for this purpose.
into the quart container and mix thoroughly with a spatula:
Suitable equipment may be obtained from C. W. Brabender Instrum
...
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