ASTM D4640-86(2001)
(Test Method)Standard Test Method for Determining Stroke Cure Time of Thermosetting Phenol-Formaldehyde Resins
Standard Test Method for Determining Stroke Cure Time of Thermosetting Phenol-Formaldehyde Resins
SIGNIFICANCE AND USE
This method is significant as a process control for polymerization time.
When the cure times are determined at several temperatures and plotted as time versus temperature, different resins can be compared for curing characteristics.
SCOPE
1.1 This test method covers the determination of the cure rate at any specified temperature for a thermosetting phenol-formaldehyde resin. The time at that temperature required to make a fluid mixture change into a hard immovable mass indicates speed of cure.
1.2 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.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D4640–86(Reapproved2001)
Standard Test Method for
Determining Stroke Cure Time of Thermosetting Phenol-
Formaldehyde Resins
This standard is issued under the fixed designation D4640; 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 5.2 Spatula,3by ⁄16 in. (75 by 10 mm), stainless.
5.3 Stopwatch.
1.1 This test method covers the determination of the cure
5.4 Knife, brass, putty with straight edge.
rate at any specified temperature for a thermosetting phenol-
formaldehyde resin. The time at that temperature required to
6. Procedure
make a fluid mixture change into a hard immovable mass
6.1 Adjust the hot plate to the desired test temperature.
indicates speed of cure.
1.2 This standard does not purport to address all of the
NOTE 1—Usual temperatures are 300°F (150°C), 320°F (160°C), and
safety concerns, if any, associated with its use. It is the 330°F (165°C).
responsibility of the user of this standard to establish appro-
6.2 Place an approximately 0.5-g specimen on the hot plate
priate safety and health practices and determine the applica- 2 2
and spread over an approximately 2-in. (130-mm ) area with
bility of regulatory limitations prior to use.
a clean spatula as quickly as possible. Start the stopwatch
immediately upon adding the specimen to the hot plate, then
2. Terminology
stroke steadily across the specimen in alternating smoothing
2.1 Definitions of Terms Specific to This Standard:
and patting motions.
2.1.1 stroke cure time—the time required for a resin being
6.3 As the resin approaches the cured stage, it becomes
held at a specified temperature on a hot plate and being stroked
more viscous and stringy. Stop the stopwatch when the resin on
with a spatula, to adhere to the hot plate and not to the spatula.
the hot plate and the spatula no longer adhere to each other.
Record the elapsed time.
3. Summary of Test Method
6.4 Remove cured resin from hot plate immediately with the
3.1 This test method employs the use of controlled heat and
straight edged putty knife.
a thin layer of resin to determine the time in seconds required
NOTE 2—The longer on the hot plate, the harder it is to remove.
to change from a fluid stage to a cured immovable stage.
NOTE 3—Test results can be affected by differences in construction of
hot plates, the stroking and patting with spatula, and the starting and
4. Significance and Use
stopping of the stopwatch.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.