1、Designation: D 4640 86 (Reapproved 2001)Standard Test Method forDetermining Stroke Cure Time of Thermosetting Phenol-Formaldehyde Resins1This standard is issued under the fixed designation D 4640; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the curerate at any specified temperature for
3、a thermosetting phenol-formaldehyde resin. The time at that temperature required tomake a fluid mixture change into a hard immovable massindicates speed of cure.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us
4、er of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 stroke cure timethe time required for a resin beingheld at a specified temperature
5、on a hot plate and being strokedwith a spatula, to adhere to the hot plate and not to the spatula.3. Summary of Test Method3.1 This test method employs the use of controlled heat anda thin layer of resin to determine the time in seconds requiredto change from a fluid stage to a cured immovable stage
6、.4. Significance and Use4.1 This method is significant as a process control forpolymerization time.4.2 When the cure times are determined at several tempera-tures and plotted as time versus temperature, different resinscan be compared for curing characteristics.5. Apparatus5.1 Electric Hot Cure Plat
7、e, with a smooth surface free ofrough spots with adjustable control to hold the temperaturewithin 3.5F (2C) (Note 1).5.2 Spatula,3by716 in. (75 by 10 mm), stainless.5.3 Stopwatch.5.4 Knife, brass, putty with straight edge.6. Procedure6.1 Adjust the hot plate to the desired test temperature.NOTE 1Usu
8、al temperatures are 300F (150C), 320F (160C), and330F (165C).6.2 Place an approximately 0.5-g specimen on the hot plateand spread over an approximately 2-in.2(130-mm2) area witha clean spatula as quickly as possible. Start the stopwatchimmediately upon adding the specimen to the hot plate, thenstrok
9、e steadily across the specimen in alternating smoothingand patting motions.6.3 As the resin approaches the cured stage, it becomesmore viscous and stringy. Stop the stopwatch when the resin onthe hot plate and the spatula no longer adhere to each other.Record the elapsed time.6.4 Remove cured resin
10、from hot plate immediately with thestraight edged putty knife.NOTE 2The longer on the hot plate, the harder it is to remove.NOTE 3Test results can be affected by differences in construction ofhot plates, the stroking and patting with spatula, and the starting andstopping of the stopwatch.7. Report7.
11、1 Report the following information:7.1.1 Stroke cure time in seconds; record to the nearestwhole number.7.1.2 Test temperature.8. Precision and Bias8.1 No statement is made about either the precision or biasof this method for measuring stroke cure since the resultmerely states whether there is confo
12、rmance to the criteria forsuccess specified in the procedure.9. Keywords9.1 phenol-formaldehyde resins; stroke cure time1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.33 o
13、n Polymers and Resins.Current edition approved Nov. 28, 1986. Published January 1987.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ASTM International takes no position respecting the validity of any patent rights asserted in connec
14、tion with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsib
15、le technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful con
16、sideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100
17、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 46402
