1、Designation: F470 89 (Reapproved 2009)Standard Practice forCaking Temperature of Dry Electrostatic Toner1This standard is issued under the fixed designation F470; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the determination of the tempera-ture at which a dry toner will cake as storage temperatures areraised.1.
3、2 In certain cases the effects of pressure or pressurecombined with heat can cause blocking and caking of a drytoner. This recommended practice does not provide for evalu-ation of such pressure effects.1.3 This practice consists of testing samples at controlledtemperatures and evaluating them for an
4、y sign of blocking aftera specified period.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
5、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 Dry toners for use in electrostatic copiers and printersare normally free-flowing powders at room temperatures. Theyare o
6、ften formulated to fuse at elevated temperatures as part ofthe electrostatic printing and copying process. The specifictemperature at which fusing takes place has implications ofpremature change in the physical characteristics of a giventoner, defined as blocking or caking. This is undesirable, butc
7、an result when the dry toner is subjected to temperatures in therange of its fusing point during conditions of transport, storage,or local handling; as well as to the environmental parameters ina given location after the product is introduced and held for usein the machine reservoir itself.3. Appara
8、tus3.1 Circulating Air Oven, forced, provided with a thermom-eter and capable of being set at various temperatures and ofremaining at 61C over a range from 40 to 80C.3.2 Weighing Dishes, round, aluminum, approximately 60mm in diameter and 17 mm deep.3.3 Balance, capable of weighing 10 g with a preci
9、sion of0.1 g.3.4 Spatulas, Tongs, etc.4. Procedure4.1 Set the oven to remain at 40C.4.2 In separate aluminum weighing dishes, weigh twosamples each of 5.0 g of toner and, using a spatula, spread thesamples evenly over the dish bottoms. Provide the dishes withsuitable covers.4.3 Place one covered dis
10、h and sample in the oven, close toits center, and leave at 40C for 24 h. Keep the other sample atroom temperature.4.4 Remove the dish and sample from the oven, allow tocool, examine visually, stir with a spatula, and look for anyevidence of caking. Use the room temperature sample forcomparison purpo
11、ses.4.5 If the oven-treated sample shows any evidence ofclumping, record its blocking temperature as below 40C. If noevidence is noted, set the oven for 45C and repeat with a freshsample of toner. Repeat the test at 5C increments until thecaking temperature is determined. If the sample does not cake
12、before or at 80C, record its blocking temperature as above80C.5. Report5.1 Report the blocking temperature or the caking tempera-ture.6. Precision6.1 When this practice is used to compare two or moretoners within a laboratory, the comparable ranking order isrepeatable. Because the interpretation of
13、results is dependentupon the subjectivity of the observations, reproducibility be-tween laboratories may not be possible.1This practice is under the jurisdiction of ASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.04 onElectrostatic Imaging Products
14、.Current edition approved Feb. 1, 2009. Published February 2009. Originallyapproved in 1976. Last previous edition approved in 2003 as F470 89(2003). DOI:10.1520/F0470-89R09.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This
15、standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information17. Keywords7.1 caking temperature; dry toners; electrostatic tonersASTM International takes no position respecting the validity of any patent rights ass
16、erted in connection 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 b
17、y the responsible 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 rece
18、ive careful consideration 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 Inte
19、rnational, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F470 89 (2009)2
