1、Designation: D 957 06Standard Practice forDetermining Surface Temperature of Molds for Plastics1This standard is issued under the fixed designation D 957; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice is intended for determining the tempera-ture at a specified point or points on the surface of the cavityand base of a
3、mold for plastics. By determining the temperatureat as many points as deemed necessary, the overall temperaturecondition of the surface can be determined.1.2 The values stated in SI units are to be regarded asstandard. The values in brackets are given for information only.1.3 This standard does not
4、purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no similar ISO standard.2.
5、Summary of Practice2.1 With the use of a calibrated surface pyrometer, theoverall temperature condition of a mold for plastics can bedetermined by taking readings at a specified point or manypoints on the mold surface.3. Significance and Use3.1 The properties of molded parts and the ease of produc-i
6、ng satisfactory specimens are influenced by the temperature ofthe mold. It is desirable to know the actual mold temperaturewhich may be different from the mold temperature controlmedium.3.2 The user should be aware of temperature differencesacross the mold/thermocouple interface and at leads and sho
7、uldtake precautions to minimize such differences.4. Apparatus4.1 PyrometerA calibrated surface pyrometer traceable toa national metrology institution (NMI)2standard and accurateto within 61.5C shall be used.5. Procedure5.1 The size, shape, and contours of a mold will determinethe location and number
8、 of points at which temperaturereadings should be observed. Take temperature readings at asmany points as deemed necessary to determine the temperaturecondition of the mold surface. At a minimum, it is suggestedthat temperature be measured at the mold center, near the edge,and at least two different
9、 but intermediate points between thecenter and edge.5.2 Place the thermocouple of the pyrometer at any speci-fied point on the surface of the cavity and base of the mold,making certain that good contact is maintained between thetwo (see Note 2). Maintain contact until the scale reachesequilibrium. R
10、ecord the temperature reading on the scale at thispoint.NOTE 2Wax may be used to ensure intimate contact between the moldsurface and the thermocouple of the pyrometer. This is accomplished byallowing a small portion of wax, or any suitable material with a lowmelting point, to melt at the point where
11、 the temperature reading is to betaken. The thermocouple is then placed in the puddle of molten material.6. Keywords6.1 base; cavity; mold temperature; pyrometer1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.09 on Specime
12、n Preparation.Current edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1948. Last previous edition approved in 2006 as D 957 - 95 (2006)e1.2NMI includes such organizations as the National Institute of Standards andTechnology.1*A Summary of Changes section appears at th
13、e end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D 957 - 95(2006)e1) that may impact the use
14、of this standard. (September 1, 2006)(1) Replaced NIST in 4.1 with a more general reference tonational metrology institutions.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are e
15、xpressly 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 responsible technical committee and must be reviewed every five years andif not rev
16、ised, 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 consideration at a meeting of theresponsible technical committee, which you m
17、ay 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 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).D957062
