ASTM C419-1994(2000) Standard Practice for Making and Curing Test Specimens of Mastic Thermal Insulation Coatings《胶泥绝热涂层的试样制作与养护的标准实施指南》.pdf

1、Designation: C 419 94 (Reapproved 2000)Standard Practice forMaking and Curing Test Specimens of Mastic ThermalInsulation Coatings1This standard is issued under the fixed designation C 419; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi

2、sion, 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 practice covers the preparation of specimens ofmastics and coatings in the form of cured sheet

3、s or films thatmay be used in other procedures for evaluation of physicalproperties.1.2 Three procedures are described for casting and curing(Note 1) mastics and coatings of all types for thermal insula-tion.NOTE 1The term “cure” is used primarily to denote the condition thatdevelops as the result o

4、f loss of volatile matter but also to denote possiblesubsequent changes in chemical or physical properties due to crosslinking.1.2.1 Procedure A is intended to provide a specimen ofcontrolled thickness applied to insulation, and equivalent inother respects to that obtainable under field application

5、condi-tions. The thermal insulation intended for field use may bespecified as the backing.1.2.2 Procedure B is intended to provide a free-filmspecimen of controlled thickness having smooth surfaces onboth sides. This type is required for some types of physicaltesting.1.2.3 Procedure C is intended to

6、 provide a free-filmspecimen of controlled thickness having one smooth surface(as field applied).1.3 The procedures of this practice are not intended for theevaluation of application properties. These are covered in TestMethods C 461 and Guide C 647.1.4 The values stated in inch-pound units are to b

7、e regardedas the standard. The values given in parentheses are forinformation only.1.5 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 practices and

8、determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 461 Test Methods for Mastics and Coatings Used WithThermal Insulation2C 533 Specification for Calcium Silicate Block and PipeThermal Insulation2C 647 Guide to Properties and Tests of Masti

9、cs and CoatingFinishes for Thermal Insulation2D 6 Test Method for Loss on Heating of Oil and AsphalticCompounds33. Summary of Practice3.1 Mastics and coatings are applied by a metal blade tothermal insulation backing material in a thickness regulated byguide bars. Moderate heat is applied to the spe

10、cimens to dry orotherwise cure them.4. Significance and Use4.1 The method of preparation of test specimens of masticthermal insulation coatings can have an impact upon valuesobtained during testing. Testing laboratories should follow thispractice to help ensure the reproducibility of test methods fo

11、rwhich a cured sheet or film of a mastic thermal insulationcoating is required.5. Apparatus5.1 Guide BarsTwo rectangular steel bars of thicknessequal to the desired wet thickness of the applied mastic orcoating. The guide bars shall be equal in length to the totallength of the specimens. For use on

12、relatively soft backingmaterial, the guide bars may be equipped with pins projectingfrom the lower surface at each end, which can be forced intothe backing to hold the bars in position during preparation ofthe test specimen.5.2 Strike-Off Bar A flat strip of rigid metal, not less than2 in. (51 mm) g

13、reater in length than the width of the specimen.One edge shall be smooth and straight.5.3 Leveling Roller One section of straight 112-in. (38-mm) stainless steel pipe or any other convenient cylindricalleveling tool. The tool shall have a smooth surface. Minimumlength shall be 2 in. (51 mm) longer t

14、han the width of thespecimen.5.4 Backing Material Unless otherwise specified by the1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.33 on InsulationFinishes and Moisture.Current edition approved Dec. 15, 1994. Pu

15、blished February 1995. Originallypublished as C 419 58 T. Last previous edition C 419 81 (1990).2Annual Book of ASTM Standards, Vol 04.06.3Annual Book of ASTM Standards, Vol 04.04.1Copyright ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.procedure for the test to be mad

16、e, the backing for the specimenshall consist of commercial block-type calcium silicate insula-tion meeting the requirements of Specification C 533 andmeasuring 2 by 18 by 24 in. (51 by 457 by 610 mm). Thebacking block may be prepared by assembling not more thanthree blocks of smaller dimensions by t

17、he use of suitableadhesive or pins, in such a manner as to form a solid, rigidblock.5.5 Release Paper A smooth, dense white paper coated onone side with dextrin, or other water-soluble gum.4Size shouldbe approximately the same as the backing block.NOTE 2Films coated with PTFE or other suitable nonso

18、luble releaseagent may be used as an acceptable alternative.6. Preparation of Test Specimens6.1 Stir the mastic or coating until uniform throughout thecontainer before removing the sample for specimen prepara-tion.6.2 Determine the percent volatile matter by weight inaccordance with Test Methods C 4

19、61, for use in calculating thedegree of cure in 7.1.2.6.3 Unless otherwise specified, lay down films to a nominalwet thickness of 0.125 in. (3.2 mm).6.4 Procedure A (Adhered Film)For the determination ofdegree of cure as described in 7.1.2, prepare one extraspecimen in addition to the number require

20、d by the otherprocedures in which they are to be used. If a primer orpretreatment of the block is specified, apply to the testspecimen in accordance with the recommendations of themanufacturer of the mastic or coating. Place and secure guidebars of a thickness equal to the desired wet mastic thickne

21、ss onthe backing material along each of the long edges. Fill the areabetween the guide bars with mastic and smooth out with atrowel to a level about 0.063 in. (1.6 mm) above the guide bars.Place the strike-off bar upon the guide bars at one end of thefilled area and move it slowly to the other end o

22、f the specimen,pushing the mastic along the surface of the backing. Asee-sawing motion of the strike-off bar will be found to aid inuniform distribution of the mastic. As the mastic is distributed,take care to prevent inclusion of air pockets. Move thestrike-off bar from end to end of the specimen i

23、n bothdirections, removing the excess material and filling the depres-sions, until a coat of uniform thickness extending from end toend of the specimen covers the entire space between the guidebars. Remove the guide bars without disturbing the wetspecimen.6.5 Procedure B (Free Film)For the determina

24、tion ofdegree of cure as described in 7.1.2, prepare one extraspecimen in addition to the number required by the otherprocedures in which they are to be used. Place a sheet of therelease paper on the backing block so that the coated surface ofthe paper faces upward, away from the backing block. Plac

25、eand secure guide bars of thickness equal to the desired wetmastic thickness on the release paper along each of the longedges. Fill the area between the guide bars with mastic andsmooth out with a trowel to a level about 0.063 in. (1.6 mm)above the guide bars. Place on the freshly applied masticanot

26、her sheet of release paper with the coated surface facingthe mastic, in the following manner: Place a short edge of thecoated paper at one end of the mastic-filled area and graduallyroll the paper into the wet mastic, using the leveling roller.Take care to prevent formation of air pockets, or bubble

27、s, underthe paper. When firmly in contact with the mastic, roll out thepaper-covered mastic until its thickness matches that of theguide bars. Then remove the guide bars without disturbing thethickness of the specimen or the position of the paper. Aconvenient method for accomplishing this is to slit

28、 the paperwith a sharp blade along the inside length of the guide bars.6.6 Procedure C (Free Film)For the determination ofdegree of cure as described in 7.1.2, prepare one extraspecimen in addition to the number required by the otherprocedures in which they are to be used. Place a sheet of thereleas

29、e paper on the backing block so that the coated surface ofthe paper faces upward, away from the backing block. Placeguide bars of thickness equal to the desired wet masticthickness on the release paper along each of the long edges. Fillthe area between the guide bars with mastic and smooth outwith a

30、 trowel to a level about 0.063 in. (1.6 mm) above theguide bars. Place the strike-off bar upon the guide bars at oneend of the filled area and move it slowly to the other end of thespecimen, pushing the mastic along the surface of the backing.A see-sawing motion of the strike-off bar will be found t

31、o aidin uniform distribution of the mastic. As the mastic is distrib-uted, take care to prevent inclusion of air pockets. Move thestrike-off bar from end to end of the specimen in bothdirections, removing the excess material and filling the depres-sions, until a coat of uniform thickness extending f

32、rom end toend of the specimen covers the entire space between the guidebars. Remove the guide bars without disturbing the wetspecimen.6.7 When a reinforcing membrane is specified, apply themastic in two separate coats of equal thickness unless other-wise specified. Immediately following the first co

33、at press themembrane into the wet mastic. Then apply the second coat tothe required thickness.7. Curing Prepared Specimens7.1 Procedure A (Adhered Film):7.1.1 During the first 24-h hold the test specimens at 60 to80F (15 to 27C). At the end of the 24-h period remove thespecimens to a thermostaticall

34、y controlled oven having atemperature of 150 6 5F (63 to 68C) and hold in this ovenuntil the desired degree of cure has been reached.7.1.2 To determine the degree of cure, take from the extraspecimen a sample of the coating from an area typical of thatto be subjected to test conditions during later

35、procedures.Determine the percentage of volatile liquids evaporated fromthe mastic during the curing as follows: Weigha1to2-gsample to the nearest 0.001 g and place it for a period of5hat220 6 5F (104 6 3C) in an oven conforming to therequirements specified in Test Method D 6. At the conclusionof the

36、 5-h heating period, remove the sample from the oven,cool to room temperature, and weigh to the nearest 0.001 g.Calculate the loss in weight as a percent of the weight before4A suitable paper is “Ideal” gummed paper, White No. 534D, supplied by Allingand Cory, 1300 W. Lehigh Ave., Philadelphia, PA 1

37、9132.C 4192heating. Calculate the degree of cure as follows:Degree of cure, % 5 A/B! 3 100 (1)where:A = percent loss in weight, andB = percent volatile matter (6.2).7.2 Procedures B and C (Free Film):7.2.1 Do not remove the specimens from the backing block.Allow the specimens to cure for 7 days at 6

38、0 to 80F (15 to27C). At the end of the 7-day period transfer the specimens(still on the backing blocks) to a thermostatically controlledoven having a temperature of 150 6 5F (63 to 68C). Hold inthis oven for a minimum of 14 days, and for as long thereafteras may be necessary to reach the desired deg

39、ree of cure.Determine the degree of cure in accordance with 7.1.2.7.2.2 Conditioning of Free FilmAllow the specimens tocool, remove them from the backing block, and immerse in tapwater at approximately 50F (10C). When the paper coatinghas softened (usually 20 to 30 min), strip all the paper from the

40、specimens and rinse them in cool (50F, 10C) water until nowater-soluble gum remains on the surfaces. Blot carefully toremove excess water and allow to dry at room temperature withgood ventilation. Before using the specimens in further tests,remove and discard the outer 0.050 in. (13 mm) of masticaro

41、und the perimeter.7.2.3 Measure dry thickness at several locations to thenearest 0.001 in. (0.025 mm) with a suitable ratchet microme-ter, and record. The dry thickness at any point shall deviate notmore than 10 % from the average thickness.8. Report8.1 Since this practice covers only the preparatio

42、n andcuring of specimens to be tested by other methods, no report isnecessary. Data here obtained should be included in the reportof the succeeding test. These data include procedure used, drythickness of specimen, number of coats, presence of primer ormembrane, or both, degree of cure, and any devi

43、ation from thestated procedure.9. Keywords9.1 mastic; thermal insulation; thermal insulation coatingThe American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard. Users of this standard are

44、 expressly advised that determination of the validity of any suchpatent rights, and the risk of 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 r

45、evised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend. I

46、f you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM, 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 above address or at610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website (www.astm.org).C 4193