1、Designation:D 1211 97Standard Test Method forTemperature-Change Resistance of Clear NitrocelluloseLacquer Films Applied to Wood1This standard is issued under the fixed designation D 1211;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisio
2、n,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 determination of the resistanceto checking and cracking of clear nitrocellulose lacq
3、uer filmsapplied to wood or plywood substrates when subjected tosudden changes from high to low temperatures.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesaf
4、ety 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.2.Referenced Documents2.1 ASTM Standards:D 805 Methods for Testing Veneer,Ply
5、wood,and OtherGlued Veneer Constructions2D 2571 Guide for Testing Wood Furniture Lacquers33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 True cold-checks on solid wood show as one or morestraight cracks on the applied film.Cold-checks manifestthemselves in either of two ways:3
6、.1.1.1 Long continuous wavy lines with the grain or atvarious directions at angles that can be perpendicular to thedirection of the grain.3.1.1.2 Innumerable fine lines erratic in direction and lengthforming a network over a portion or all of the panel.This effectmay be likened to crazing of the lac
7、quer film.3.1.1.3 On plywood the direction of the cracks will oftenvary because of the stresses set up by other than the topstratum.Therefore,all checks may be considered as failures,and appropriate notations on the character of the cracks mustbe made to assist in the interpretation.While it is reco
8、gnizedthat cracks in the substrate may occur(veneer checking),failures observed in the lacquer coating may be due to action ofmoisture(humidity)or of cold,or both.Checking caused bymoisture appears along the grain and is characterized by shortcracks(usually not more than12in.(13 mm)in length)occurri
9、ng either singly or in clusters.These lines or clustersmay progress along the grain in a discontinuous fashion.Should either veneer checking or moisture checking be ob-served,the test should be discontinued,and rerun.3.1.2 The checks may be perceptible only by visual obser-vation of the panels at an
10、 angle,under a strong light,or thecracks may be wide enough to be readily discernible in directdaylight.4.Summary of Test Method4.1 Lacquer-coated wood panels are subjected first to a hightemperature,followed by an exposure to low temperature,andthen a return to room temperature for given periods of
11、 time,which constitutes one cycle.The method does not define thenumber of cycles which a lacquer must withstand,this condi-tion being a requirement which must be agreed upon by thepurchaser and the seller.5.Significance and Use5.1 Acommon type of failure of clear films applied to woodis cracking or
12、checking that may occur over a period of timeeither with the grain or at an angle.This cold check test isdesigned to accelerate the appearance of checks or cracks bycycling the temperature.NOTE1Except when elaborate precautions are taken to control themoisture content of the wood before and after fi
13、nishing and during the test,failures may quite often occur as a result of dimensional changes in thewood due to moisture change rather than temperature change.6.Apparatus6.1 Refrigerator(Dry Ice)The refrigerator should be awell-insulated box,cooled by air which has been circulatedover solid carbon d
14、ioxide(dry ice).The air must strike thepanels indirectly after passing over the solid carbon dioxide.The unit shall have a capacity and temperature control suffi-cient to cool the test panels in accordance with the require-ments prescribed in Section 9.6.2 Mechanical RefrigeratorAs a less desirable
15、alterna-tive,a well-insulated mechanical refrigerator may be usedhaving sufficient capacity to cool the test panels in accordance1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D
16、01.52 on Factory-Coated Wood Building Products.Current edition approved Dec.10,1997.Published August 1998.Originallypublished as D 1211 52.Last previous edition D 1211 87(1993)e1.2Discontinued;see 1976 Annual Book of ASTM Standards,Part 22.3Annual Book of ASTM Standards,Vol 06.02.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMwith the requirements prescribed in Section 9.The refrigeratorshoul