1、Designation: D 4147 99 (Reapproved 2007)e1Standard Practice forApplying Coil Coatings Using The Wire-Wound DrawdownBar1This standard is issued under the fixed designation D 4147; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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.e1NOTEAn editorial correction was made in Section 7 in November 2007.1. Scope1.1 This practice covers a procedure for app
3、lying a coatingfilm of uniform thickness on a flat panel using the wire-wounddrawdown bar.1.2 This standard does not 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 practic
4、es and determine the applica-bility of regulatory limitations prior to use.2. Summary of Practice2.1 A flat panel is secured on a firm horizontal surface. Anample amount of coating is poured across one end of the paneland the drawdown bar placed behind the coating. The bar isthen drawn with uniform
5、pressure and speed along the lengthof the panel toward the operator to apply a uniform film. Thewet and dry film coating thickness obtained is dependent on thecombination of the bar used, the volume solids of the coating,and the speed of the drawdown motion.3. Significance and Use3.1 This practice i
6、s useful in the laboratory to simulateroll-coated films.4. Apparatus4.1 Wire-Wound Drawdown BarsA set of stainless steelwire-wound drawdown bars of sufficient diameter to preventbowing during application. These bars are manufactured sothat the diameter of the wire wound on the bar controlsthickness
7、of the wet film applied. The choice of specificdrawdown bar is dependent on the dry film thickness requiredand the volume solids of the coating under test.4.2 Devices for Securing Panels:4.2.1 Magnetic Chuck for securing steel panels to eliminatebowing.4.2.2 Vacuum Plate for securing very lightweigh
8、t nonmag-netic panels.4.2.3 Tape for securing the top of thin-gage panels.4.2.4 Mechanical Drives, for securing panels and automat-ing the drawdown procedure.5. Hazards5.1 The flash points of most solvents used in coatings andrelated products are low enough that adequate ventilation isneeded to avoi
9、d exceeding 25 % of the lower explosive limitsof the solvent when preparing and baking the panels. Thesesolvents could be toxic, care should be taken to avoid inhala-tion of the vapors and unnecessary contact of the solvents withthe skin.6. Procedure6.1 Deburr panels so edges are smooth. Secure a fl
10、at panelto be coated on a firm, uniform, level surface. To providesufficient testing surface pour an ample amount of coatingacross the end of the panel. Place the drawdown bar behind thecoating and pull into the coating. Rotate the drawdown bar inthe coating to ensure complete wetting of the coating
11、 in thethreads of the bar. Apply uniform pressure across the contactlength of the drawdown bar and hold it firmly without allowingrotation. Using only one pass, draw the bar along the length ofand off the panel at a uniform speed so that a continuous filmis produced. Application of the coating is de
12、pendent upon therheology, type of coating, and speed and pressure to achievethe uniform desired film. Remove the coated panel and bake,force dry, or air dry the coating in accordance with its type soits dry film thickness can be measured.Aheavier film thicknessis obtained along the edges of the pane
13、l and possibly at the topof the panel where the coating was poured. For a two-coatsystem, the side edges must be trimmed to eliminate theheavier areas on the first coat before applying the second coat.7. Keywords7.1 coil coatings; drawdown bars1This practice is under the jurisdiction of ASTM Committ
14、ee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.53 on Coil Coated Metal.Current edition approved Nov. 1, 2007. Published November 2007. Originallyapproved in 1982. Last previous edition approved in 2003 as D 4147 99 (2003).1Copyrig
15、ht 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 connection with any item mentionedin this standard. Users of this standard are expressly advised th
16、at 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 revised, either reappr
17、oved 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 may attend. If you f
18、eel 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).D 4147 99 (2007)e12
