ASTM_D_658_-_91_scan.pdf

STN-Db58 93 W 0759530 0070698 T Designation:D 658-91 AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 RaceSt.Philadelphia,Pa 19103 Reprinted from the Annual Book of ASTM Standards.Copyright ASTM If not listed in the current combined index,will appear in the next edition.Standard Test Method for Abrasion Resistance of Organic Coatings by Air Blast Abrasive This standard is issued under the fixed designation D 658;the number immediately following the designation indicafes 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(e)indicafes an editorial change since the last revision or reapproval.1.Scope 1.1 This test method covers the determination of the resistance of organic coatings to abrasion produced by an air blast of abrasive on coatings applied to a plane,rigid surface,such as a metal or glass panel.1.2 This standard does not purport to address the safety problems associated with its use.It is the responsibility o f the user o f this standard to establish appropriate safety and health practices and determine the applicability o f regulatory limitations prior to use.2.Referenced Documents 2.1 ASTM Standards:D823 Test Methods for Producing Films of Uniform Thickness of Paint,Varnish,and Related Products on Test Panels2 D968 Test Method for Abrasion Resistance of Organic Coatings by Falling Abrasive2 D1005 Test Methods for Measurement of Dry Film Thickness of Organic Coatings Using Micrometers2 D 1 186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous Base2 D 1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive Coatings Ap-plied to a Nonferrous Metal Base2 E 11 Specification for Wire-Cloth Sieves For Testing Purposes3 3.Terminology 3.1 Description o f Term Specific to This Standard:3.1.1 abrasion resistance-the weight of abrasive required to wear through a unit fdm thickness of the coating.4.Summary of Test Method 4.1 An abrasive under the action of a controlled air stream is allowed to impinge on a coated panel until the substrate becomes visible.The amount of abrasive used per unit film thickness is reported as the abrasion resistance of the coating.This test method is under the juridiction of ASTM Committee D-1 on Paint and Related Coatings and Materials and is the direct responsibility of Subcom-mittee W1.23 on Physical Properties of Applied Paint F i l m s.Current edition approved Feb.22,1991.Published Apd 1991.Originaiiy published as D 658-42 T.Last previous edition D 658-8 1(1 9 8 6).Anniial Book o$ASTMStandards,Vol 06.01,Annical Book o f ASTM Standards,Vol 1 4.0 2.FROM 41R CONTROL APPARATUS FLOWMETER a FIG.1 Abrasion Test Apparatus(Closed)5.Significance and Use 5.1 This test method and Test Method D 968 are two similar methods to measure the abrasion resistance of organic coatings.5.2 These test methods provide approximately the same rankings of coatings for abrasion resistance.5.3 Each of the test methods has been found useful i n rating the abrasion resistance of specific types of coatings.6.Apparatus 6.1 Abrasion Tester:such as is illustrated in Figs.1 and 2 equipped with a giass nozzle as illustrated in Fig.3,The specimen stage should be set at 45 from horizontal.NOTE 1-To prevent clogging of the tube outlet of the abrasive holder by extraneous material,a screen can be inserted at the throat of 4Drawings for a suitable tester of this type are available f r o m ASTM Headquarters.Order Adjunct No.12-406580-00.1 NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.GY i*t t z-LW*FROM WNOMETER REAR LAMP2 ABRASION NOZZLE-ASTM Db58 93 0759530 0070b99 3 4 m D658&-FRONT LAMP SPECIMEN s r m FIG.2 Abrasion Test Apparatus(Open)the holder.Insect screen(approximately 270 openings per square inch)is suitable for this purpose.6.2 Air Supply,oil-free,under pressure,capable of main-taining a selected pressure within f 200 Pa.6.3 Standard Abrasives-Silicon carbide grain passing a No.170(90-pm)sieve and retained on a No.200(75ym)sieve.NOTE 2-To obtain maximum accuracy and precision of results,the abrasive should be sieved for a minimum of Y2 h with vigorous agitation,and only that portion which passes through a No.170(90-ym)sieve and is retained on a No.200(75-pm)sieve should be used in the test.The retained portion of the abrasive is considered satisfactory if a minimum of 85%by weight meets the grain size requirements of 90 to 75 ym.Use the sieves described in Specification E 1 1.7.Specimens 7,l Apply uniform coatings of the material to be tested to a plane,rigid panel,such as metal or glass.Prepare a minimum of two coated panels for the material.7,2 Cure the coated panels under conditions of humidity and temperature as agreed upon by the purchaser and seller.NOTE 3-The coatings should be applied in ac