ASTM D3274-1995(2002) Standard Test Method for Evaluating Degree of Surface Disfigurement of Paint Films by Microbial (Fungal or Algal) Growth or Soil and Dirt Accumulation《通过真菌(真菌.pdf

1、Designation: D 3274 95 (Reapproved 2002)Standard Test Method forEvaluating Degree of Surface Disfigurement of Paint Filmsby Microbial (Fungal or Algal) Growth or Soil and DirtAccumulation1This standard is issued under the fixed designation D 3274; the number immediately following the designation ind

2、icates the year oforiginal adoption or, in the case of revision, 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.This standard has been approved for use by agencies

3、of the Department of Defense.1. Scope1.1 The photographic reference standards available for usewith this test method provide a numerical basis for rating thedegree of fungal and algal growth or soil and dirt accumulationon paint films.1.2 This standard does not purport to address all of thesafety co

4、ncerns, 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 4610 Guide for Determining the Prese

5、nce of and Remov-ing Microbial (Fungal or Algal) Growth on Paint andRelated Coatings22.2 ASTM Adjuncts:Pictorial Photographic Standards33. Terminology3.1 Types of Fungal and Algal Growth Fungi are het-erotrophs capable of reproducing both asexually and sexually.Asexual reproduction takes place eithe

6、r by the fragmentationof the mycelium or by the production of spores. Sexualreproduction can occur by fusion of gametes, penetration of agamete into a reproductive structure known as a gametangium,or by fusion of gametangia. Some common definitions include:3.2 sporean asexual reproductive cell capab

7、le of devel-oping into a mature fungus without fusion with another cell.3.2.1 DiscussionSpores tend to be spherical in morphol-ogy and are observed singly or in clusters. Spores may or maynot be associated with fungal mycelia and can range in a widevariety of colors. Although primarily gray or black

8、, somespores are even green in color and have been mistaken asterrestrial algae. Spores of Aureobasidium pullulans magnified1003 are shown in Fig. 1.3.3 hyphaethread-like, tubular, fungal filaments that com-pose the mycelium. Hyphae may appear individually or havespores attached.3.3.1 DiscussionHyph

9、ae of Aureobasidium pullulans,magnified 503 are shown in Fig. 2.3.4 myceliumvegetative mass of hyphae forming the bodyof a fungus.3.5 fruiting bodyfungus structure consisting of special-ized hyphae where sexual reproduction occurs.3.6 Amorphous growth typical of an alga such as Chloro-coccum Sp. app

10、ears in Fig. 3 at a magnification of 393.Terrestrial algae can appear green to dark brown in color.4. Significance and Use4.1 The growth of fungi and algae in and on the surface ofpaint films represents a major cause of discoloration ordisfigurement of painted surfaces. Because of their darkpigmenta

11、tion, it is frequently difficult to distinguish fungi andalgae from soil or dirt particles. The use of magnification of asmuch as 1003 affords easy distinguishability among fungalspores, fungal mycelia, algae, and dirt and is recommended incases where such difficulty is apparent.4.2 Dirt accumulatio

12、n observed on specimens can occurmore readily with coatings formulated at lower pigmentvolume concentration or those containing softer resins.4.3 Use of Photographic Standards:34.3.1 The photographic reference standards that are part ofthis test method are for illustration purposes and should be use

13、dfor visual comparisons.4.3.2 The photographic standards illustrated in Fig. 4 ratethe disfigurement of paint films from 0 to 8. A rating of 10would indicate a film totally absent of disfigurement byparticulate matter.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Rela

14、ted Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edition approved April 15, 1995. Published June 1995. Originallypublished as D 3274 73 T. Last previous edition D 3274 82 (1988)e1.2Annual Book of ASTM Standards, Vol 06.01.3A

15、vailable from ASTM International Headquarters (order Adjunct ADJD3274).Copies of the pictorial photographic standards are contained in the publicationPictorial Standards of Coating Defects, which may be obtained from the Federationof Societies of Coating Technology, 492 Norristown Rd., Blue Bell, PA

16、 19422.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3.3 The ratings used in this standard more closely match anonlinear scale.5. Soil or Dirt Particles5.1 Soil or dirt particles may range from light brown toblack. The particles,

17、 viewed at 503 to 1003 magnification, aregenerally amorphous and are frequently translucent. Soil par-ticles on paint magnified 1003 are shown in Fig. 5.6. Procedure6.1 Compare each specimen with the photographic stan-dards associated with this test method to determine which mostclosely matches the

18、degree of disfigurement on the specimen.When the degree is intermediate between two adjacent stan-dards select the intermediate odd number as the disfigurementrating.6.2 The density of fungal or algal growth as well as dirtaccumulation may vary over the painted surface being evalu-ated. This variati

19、on may be the result of the location of thesurface (that is, under an eave of a house versus an exposedarea), nonuniformity of the substrate, film thickness or otherfactors. Note such variation when reporting the rating assignedto specimen under test. In examining test specimens for fungal,algal, or

20、 dirt disfigurement, make sure that the possibility offailure due to the wood substrate is recognized and reported.6.3 When microbial disfigurement is detected (or estab-lished), distinguish between algal and fungal growth. For thelatter, estimate whether spores or mycelia predominate (seeGuide D 46

21、10).NOTE 1Applying sodium hypochlorite to coatings is optional, how-ever, the invasiveness of this technique may contaminate test substratesthat could inhibit future fungal/algal growth.6.4 If fungal or algal growth is only observed on dirt or soilparticles that have accumulated on the specimen, dis

22、regard theassignment of a rating. In this case the organism is not actuallyutilizing the coating as a food source. Make sure that specialmention as to this observance is noted as agreed upon betweenall parties involved with the testing.7. Report7.1 Report the numerical disfigurement rating as define

23、d in4.3.2 and the predominant type, that is, fungi, algae, or soil.7.2 Make a notation as to the uniformity of the failurenoticed on the specimen.8. Keywords8.1 algal; disfigurement; fungal; photographic standardFIG. 1 Spores of Aureobasidium pullulans, Magnified 1003FIG. 2 Hyphae of Aureobasidium p

24、ullulans, Magnified 503FIG. 3 Amorphous Algal Growth, Magnified 393D 3274 95 (2002)2FIG. 4 Disfigurement RatingsD 3274 95 (2002)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard ar

25、e 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 by the responsible technical committee and must be reviewed every five years andif not

26、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 receive careful consideration at a meeting of theresponsible technical committee, which yo

27、u 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United

28、 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).FIG. 5 Soil Particles on Paint, Magnified 1003D 3274 95 (2002)4