DIN EN ISO 28199-2-2010 Paints and varnishes - Evaluation of properties of coating systems related to the application process - Part 2 Colour stability process hiding power re-diss.pdf

1、January 2010DEUTSCHE NORM English price group 11No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 87.040!$Ww“1565284www.

2、din.deDDIN EN ISO 28199-2Paints and varnishes Evaluation of properties of coating systems related to the applicationprocess Part 2: Colour stability, process hiding power, re-dissolving, oversprayabsorption, wetting, surface texture and mottling (ISO 28199-2:2009)English version of DIN EN ISO 28199-

3、2:2010-01Beschichtungsstoffe Beurteilung applikationsbedingter Eigenschaften von Beschichtungssystemen Teil 2: Farbstabilitt, Prozessdeckvermgen, Anlsen, Spritznebelaufnahme, Benetzung,Oberflchenstruktur und Wolkigkeit (ISO 28199-2:2009)Englische Fassung DIN EN ISO 28199-2:2010-01www.beuth.deDocumen

4、t comprises 15 pagesDIN EN ISO 28199-2:2010-01 2 National foreword This standard has been prepared by Technical Committee ISO/TC 35 “Paints and varnishes”, Subcommittee SC 9 “General test methods for paints and varnishes” (Secretariat: BSI, United Kingdom) in collaboration with Technical Committee C

5、EN/TC 139 “Paints and varnishes” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Beschichtungsstoffe und Beschichtungen (Coatings and Coating Materials Standards Committee), Working Committee NA 002-00-07 AA Allgemeine Prfverfahren fr Besc

6、hichtungsstoffe und Beschichtungen. The test method specified in ISO 28199 is based on studies by a Working Group of the European Council for Automotive R surface texture; colour in accordance with ISO 7724 (all parts). In combination with visual assessment, the following properties are determined:

7、colour stability, process hiding power, re-dissolving, overspray absorption, wetting, surface texture and mottling (this part of ISO 28199); tendency to sagging, formation of bubbles, pinholing and hiding power (ISO 28199-3). 4 EN ISO 28199-2:2009 (E) DIN EN ISO 28199-2:2010-01 1 Scope This part of

8、ISO 28199 specifies methods for the determination of colour stability, process hiding power, re-dissolving, overspray absorption, wetting, surface texture and mottling of coating materials applied to a test panel under defined conditions. 2 Normative references The following referenced documents are

9、 indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 28199-1:2009, Paints and varnishes Evaluation of properties of coatings related to

10、the application process Part 1: Relevant vocabulary and preparation of test panels 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 28199-1 apply. 4 Colour stability 4.1 General Colour stability is determined by evaluation of the values measured for a

11、 wedge-shaped base coat and constant-thickness clear coat, obtained in accordance with 9.4 of ISO 28199-1: 2009. 4.2 Evaluation Plot the colour space values determined for the wedge-shaped base coat and constant-thickness clear coat in accordance with ISO 28199-1:2009, 9.4, against the film thicknes

12、s of the base coat, and evaluate the development of the curve visually. Determine the lowest (tmin) and the highest (tmax) film thicknesses at which the curve is approximately parallel to the X-axis. With regard to parallelism, a tolerance range or a minimum gradient shall be agreed. Figures 1 and 2

13、 showing examples of film thickness plotted against lightness (L*). The Y-axis can also show the colour values a*, b*, C* and h. The range of colour stability ends at that film thickness at which the curve is no longer parallel to the X-axis. 5 DIN EN ISO 28199-2:2010-01 EN ISO 28199-2:2009 (E) Key

14、X film thickness (m) Y lightness tminstart of colour stability tmaxend of colour stability Figure 1 Graph showing colour stability (idealized) Key X film thickness (m) Y lightness aEvidence of drift in the colour values of the base coat, i.e. lack of colour stability. Figure 2 Graph showing lack of

15、colour stability 6 EN ISO 28199-2:2009 (E) DIN EN ISO 28199-2:2010-01 5 Process hiding power 5.1 General The process hiding power is determined by evaluation of the values measured for the process substrate, wedge-shaped base coat and constant-thickness clear coat, obtained in accordance with 9.4 of

16、 ISO 28199-1:2009. The lowest film thickness exhibiting colour stability (tmin) (see 4.2) is determined. 5.2 Evaluation Using the same method for evaluating the colour stability as specified in 4.2, evaluate the values measured for the process substrate, wedge-shaped base coat and constant-thickness

17、 clear coat, obtained in accordance with ISO 28199-1. Figure 3 shows an example of film thickness plotted against lightness (L*). NOTE Often the development of the curves resembles those for colour stability evaluation, but shifted into other film thickness ranges. Key X film thickness (m) Y lightne

18、ss aPoint at which a constant colour value is achieved, i.e. the base coat covers the substrate used. Figure 3 Process hiding power 6 Re-dissolving 6.1 General Re-dissolving is determined by evaluation of the values measured for the constant-thickness base coat and wedge-shaped clear coat, obtained

19、in accordance with 9.4 of ISO 28199-1:2009. For a given drying/application process it is possible that, above a certain film thickness, insufficient solvent escapes. The top layer of the base coat will interact with the solvents of the clear coat, which is applied later. This could lead to another a

20、rrangement of, for example, effect pigments, which could result in greater local differences of the colour space values at the same film thickness. 7 DIN EN ISO 28199-2:2010-01 EN ISO 28199-2:2009 (E) 6.2 Evaluation Plot the colour space values determined for the constant-thickness base coat and wed

21、ge-shaped clear coat, obtained in accordance with ISO 28199-1:2009, 9.4, against the film thickness of the clear coat. Evaluate visually the development of the curves obtained, preferably including L*25 and b*25, since the effect is best visible at 25. Figure 4 shows an example of film thickness plo

22、tted against lightness (L*). Re-dissolving will be evidenced on the curve because, as film thickness increases, the curve will begin to drift out of the range defined for colour stability (end of the plateau for colour stability). This might be due to self-colouration or yellowing of the clear coat.

23、 Key X film thickness (m) Y lightness aDrift in colour values indicates re-dissolving. Figure 4 Re-dissolving 7 Overspray absorption 7.1 General Overspray absorption is determined by evaluation of the values measured for the wedge-shaped base coat and constant-thickness clear coat, obtained in accor

24、dance with 9.4 of ISO 28199-1:2009. 7.2 Evaluation Using the values measured for the wedge-shaped base coat and constant-thickness clear coat, obtained in accordance with ISO 28199-1:2009, 9.4, plot the lightness value L*25 (see ISO 77243, 4, 5) against the film thickness of the base coat. Figure 5

25、shows an example of film thickness plotted against lightness (L*). Overspray absorption occurs when the first and second spraying stages merge with each other. This results in a steady transition from the plateau of the colour stability to the re-dissolving range (see Figure 5). 8 EN ISO 28199-2:200

26、9 (E) DIN EN ISO 28199-2:2010-01 Insufficient overspray absorption is characterized by a large number of measured points occurring in at least two areas. Key X film thickness (m) Y lightness aLarge number of measured points from first spraying stage. bLarge number of measured points from second spra

27、ying stage. Figure 5 Insufficient overspray absorption 8 Wetting 8.1 General Wetting is determined by evaluation of the values measured for the constant-thickness base coat and wedge-shaped clear coat, obtained in accordance with 9.4 of ISO 28199-1:2009. 8.2 Evaluation Using the values measured for

28、the constant-thickness base coat and wedge-shaped clear coat, obtained in accordance with ISO 28199-1:2009, 9.4, plot the values for the long-wavelength range against the film thickness, and determine the film thickness of the first wetting. Figure 6 shows an example of film thickness plotted agains

29、t long-wavelength values. 9 DIN EN ISO 28199-2:2010-01 EN ISO 28199-2:2009 (E) Key X film thickness (m) Y long-wavelength values aBeginning of wetting. bSubstrate completely wetted. cBeginning of levelling. dCoating completely level. Figure 6 Wetting 9 Surface texture 9.1 General The surface texture

30、 is determined by evaluation of the values measured for the wedge-shaped coating, obtained in accordance with 9.4.4 of ISO 28199-1:2009. 9.2 Evaluation 9.2.1 General evaluation Using the values measured for the wedge-shaped coating, obtained in accordance with ISO 28199-1:2009, 9.4.4, plot the surfa

31、ce texture values against the film thickness. Figures 7 and 8 show examples of film thickness plotted against short-wavelength and long-wavelength values. 9.2.2 Evaluation of base coats For evaluation of the base coat surface texture, use the short-wavelength values. Take the mean values of the shor

32、t-wavelength values lying within the range permitted for the paint-application process in question (the so-called process window). The short-wavelength values (see ISO 28199-1:2009, 3.16) of the base coat within the process window shall not be confused with the short-wavelength values of the clear c

33、oat. The short-wavelength values of reference strip 2 (see ISO 28199-1:2009, Figure 2) shall be clearly below the short-wavelength values of the measuring range. 10 EN ISO 28199-2:2009 (E) DIN EN ISO 28199-2:2010-01 Key X film thickness (m) Y short-wavelength values aMean value of the short-waveleng

34、th values within the process window. Figure 7 Surface texture of base coat 9.2.3 Evaluation of clear coats For the evaluation of clear coat surface texture, use the long-wavelength values. Calculate the mean value of the long-wavelength values within the process window. Key X film thickness (m) Y lo

35、ng-wavelength values aMean value of the long-wavelength values within the process window. Figure 8 Surface texture of clear coat 11 DIN EN ISO 28199-2:2010-01 EN ISO 28199-2:2009 (E) 10 Mottling 10.1 General Mottling is determined by evaluation of the values measured for the wedge-shaped base coat a

36、nd constant-thickness clear coat, obtained in accordance with 9.4 of ISO 28199-1:2009. 10.2 Evaluation Plot the lightness value L*25 against the film thickness of the base coat. Figure 9 shows an example of film thickness plotted against lightness (L*). Mottling has occurred if between the first and

37、 second spray stages, including an intermediate flash-off time close to that in the process, significant variation of the L*25 values occurs. The mottling range is limited within the ranges of hiding power and re-dissolving. These ranges can also be considered as mottling. Where mottling occurs, lar

38、ge numbers of measured points representing different levels of lightness L*25 at the same film thickness can clearly be seen on the curve. Key X film thickness (m) Y lightness aHiding power mottling at low film thickness. bMottling caused by material or application. cWet mottling at high film thickn

39、ess, possibly caused by running material. Figure 9 Example of bad mottling 11 Test report Prepare a test report in accordance with Clause 12 of ISO 28199-1:2009. 12 EN ISO 28199-2:2009 (E) DIN EN ISO 28199-2:2010-01 Bibliography 1 ISO 2808, Paints and varnishes Determination of film thickness 2 ISO

40、2813, Paints and varnishes Determination of specular gloss of non-metallic paint films at 20, 60 and 85 3 ISO 7724-1, Paints and varnishes Colorimetry Part 1: Principles 4 ISO 7724-2, Paints and varnishes Colorimetry Part 2: Colour measurement 5 ISO 7724-3, Paints and varnishes Colorimetry Part 3: Calculation of colour differences 13 DIN EN ISO 28199-2:2010-01 EN ISO 28199-2:2009 (E)