1、Designation: C581 03 (Reapproved 2008)1C581 15 An American National StandardStandard Practice forDetermining Chemical Resistance of Thermosetting ResinsUsed in Glass-Fiber-Reinforced Structures Intended forLiquid Service1This standard is issued under the fixed designation C581; the number immediatel
2、y following the designation indicates 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 () indicates an editorial change since the last revision or reapproval.This standard has been
3、 approved for use by agencies of the U.S. Department of Defense.1 NOTENote 2 was editorially revised in August 2008.1. Scope1.1 This practice is designed to evaluate, in an unstressed state, the chemical resistance of thermosetting resins used in thefabrication of reinforced thermosetting plastic (R
4、TP) laminates. This practice provides for the determination of changes in theproperties, described as follows, of the test specimens and test reagent after exposure of the specimens to the reagent: hardnessof specimens, weight change thickness, appearance of specimens, appearance of immersion media,
5、 and flexural strength andmodulus.1.1.1 This practice is also useful to evaluate other factors, such as surfacing veils and the effect of resin additives, on thechemical resistance of the resin.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses
6、are mathematicalconversions to SI units that are provided for information only and are not considered standard.NOTE 1This practice may also be used to evaluate other factors, such as surfacing veils, the effect of resin additives, and fabrication variables onthe chemical resistance of the resin.NOTE
7、 2There is no known ISO equivalent to this standard.NOTE 1There is no known ISO equivalent to this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety
8、and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating MaterialsD883 Terminology Relating to PlasticsD2563 Practi
9、ce for Classifying Visual Defects in Glass-Reinforced Plastic Laminate PartsD2583 Test Method for Indentation Hardness of Rigid Plastics by Means of a Barcol ImpressorD2584 Test Method for Ignition Loss of Cured Reinforced Resins3. Terminology3.1 Definitions of Terms:3.1.1 For definitions of terms a
10、ssociated with plastic materials, see Terminology D883.4. Significance and Use4.1 The results obtained by this practice shall serve as a guide in, but not as the sole basis for, selection of a thermosetting resinused in an RTP structure. No attempt has been made to incorporate into the practice all
11、the various factors that may enter intowill1 This practice is under the jurisdiction ofASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.23 on Reinforced Plastic Piping Systemsand Chemical Equipment.Current edition approved May 1, 2008Dec. 1, 2015. Published August
12、2008January 2016. Originally approved in 1965. Last previous edition approved in 20032008 asC581 03.C581 03(2008)1. DOI: 10.1520/C0581-03R08E01.10.1520/C0581-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of
13、 ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technicall
14、y possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C7
15、00, West Conshohocken, PA 19428-2959. United States1potentially affect the serviceability of an RTP structure when subjected to chemical environments. These factors may willpotentially include stress, different resin-to-glass ratios, and multiple veils.5. Apparatus5.1 Hardness Testing InstrumentThis
16、 shall be as described in Test Method D2583.5.2 Flexural Properties Testing Apparatus, in accordance with Test Methods D790.5.3 Thickness MeasurementA micrometer suitable for measurement to 0.001 in. (0.025 mm).5.4 Containers, of sufficient size, capacity, and inertness to allow total immersion of r
17、einforced thermosetting plastic specimensin the specific corrosives chosen for testing. These containers shall, when necessary, be capable of maintaining liquid levels ofvolatile solutions, that is, solvents. This can be accomplished by the use of reflux condensers.5.5 Heating ApparatusAconstant tem
18、perature oven, heating mantle, or liquid bath capable of maintaining temperature withinrange of 64.0F (62.2C). Proper precautions should be taken Take proper precautions if the corrosives selected are flammableliquids.5.6 Analytical Balance, suitable for accurate weighing to 0.001 g.6. Reagents6.1 T
19、he test media shall consist of the reagents or solutions to which the RTP laminates are to be exposed.7. Test Specimens7.1 Standard LaminatesPrepare standard fiber-reinforced laminates using identical reinforcement in all of the laminates. Thelaminates shall be constructed of the following materials
20、:7.1.1 Surfacing Mat (Veil)A thin mat of fine fibers used primarily to produce a smooth, resin-rich surface on a reinforcedplastic. The surfacing veil helps determine the thickness of the resin-rich layer, reduces microcracking and provides a non-wickingchemicallyresistant layer. The surfacing veil
21、shall be compatible with the resin, and manufactured with uniform fiber distributionand non-bundled fibers. The dry veil layer(s) shall be a minimum 10 mils in thickness and produce a 10 to 15 mil resin-saturatedveil layer per 10 mils of dry veil. To eliminate the surfacing veil as a variable in cor
22、rosion tests, prepare each laminate within atest group with the same surfacing veil.7.1.2 Chopped Strand MatType E glass fiber with sizing and binder compatible with the resin. Other glass fiber compositionsmay be used but should It is acceptable to use other glass fiber compositions, but using such
23、 alternate compositions shall beconsidered as variables for comparison to the standard.7.1.2.1 Note that this practice applies to E-CR glass fiber, which is a type of E glass fiber. If the E glass fiber material is of theE-CR type that information shall be identified in the test report.7.1.3 ResinCa
24、talyzed and promoted in accordance with the resin manufacturers recommendation.NOTE 2Fillers, It is acceptable to add fillers, such as antimony trioxide for improved fire retardancyperformance or thixotropes for viscosity control,may be added, but may but it is possible that this will detract from t
25、he corrosion resistance of the test laminate.7.2 Dimensions and General PropertiesThe laminates shall conform to the required dimensions and general properties of6.27.2 and be fabricated in accordance with 7.36.3. .7.2.1 Laminate SizeAsuitable laminate size has been found to be 26 by 33 in. (660 by
26、838 mm) after trimming. This laminatesize is not restrictive and other dimensions may be used. are acceptable.7.2.2 ThicknessThe thickness of the cured standard laminate shall be between 0.120 and 0.140 in. (3.05 and 3.56 mm).7.2.3 Reinforcement ContentThe glass fiber and binder shall be 4.73 6 0.47
27、 oz/ft2 (three layers of 1.5 oz/ft2 chopped strandmat 4.5 oz/ft2 having a nominal binder content of 3.5 % and two layers of 10 mil surfacing mat 0.23 oz/ft2 having a nominal bindercontent of 7 %)determined by preweighing the materials prior to construction of the laminate. This is equivalent to 23.6
28、weight % (12.5 volume %) glass fiber when using a resin having a cured specific gravity of 1.15. Such a laminate will have athickness of 0.125 in. (3.18 mm). The use of resins having different specific gravities will result in different weight percentagesof glass fiber, but the volume percentage of
29、glass fiber will remain the same. When using synthetic organic fiber surfacing veil,the glass content shall be 4.50 6 0.45 oz/ft2 ( three layers of 1.5oz/ft2 chopped strand mat having a nominal binder content of3.5 %).7.2.4 HardnessThe hardness shall be at least 90 % of that of a fully-cured clear c
30、asting of the resin, or of a similarlyconstructed laminate as defined by the resin manufacturer. Hardness shall be determined in accordance with s4.15.1. It should benoted Note that the use of synthetic veil will result in significantly lower hardness values. The hardness value will vary with thetyp
31、e of resin and number of plies of synthetic veil. The resin manufacturer should needs to be contacted for the allowable Barcolhardness value of a laminate containing synthetic veils with the specific resin.7.2.5 Laminate ConditionThe laminate shall meet Acceptance Level I of Table I of Practice D256
32、3.7.3 Fabrication of Standard LaminateThe sequence of lay-up shall be as follows:C581 1527.3.1 Apply catalyzed resin and a 10-mil (0.25-mm) surfacing mat on a flat surface covered with plastic release film or treatedwith a suitable release agent and roll to distribute resin.NOTE 3The Use the followi
33、ng formula may be used as a guide to determine the total weight of resin to be used. This is equivalent to 12.5 volume% glass fiber in the laminate. Grams resin equals grams glass fiber material per 6.2.37.2.3 times 2.82 G. Where G equals specific gravity of cured resin.Excess resin may be used It i
34、s acceptable to use excess resin due to loss by adhering to mixing containers, rollers, and other factors. A suggested amountof excess resin is 10 to 15 % by weight.7.3.2 Follow with three plies of 1.5 oz/ft2 chopped strand mat and resin. Roll after each ply to distribute and wet-out the choppedstra
35、nd mat. Rolling with a serrated roller may be done is acceptable after each ply to remove entrapped air but it shall be donein accordance with 6.3.47.3.4. The mat weight shall be within 65 % of 1.5 oz/ft2 upon weighing the full 26 by 33-in. cut (660by 838-mm) piece, (or other full dimension used, 6.
36、2.17.2.1.).NOTE 4Chopped Cut chopped strand mat should be cut so that the 26-in. dimension is across the width of the roll and the 33-in. dimension is alongthe machine direction of the mat. Mat weight variation will most commonly occur across the width of the mat. If a wide roll of mat, 52 in. (1320
37、 mm)or greater, is used, place the two plies of mat should be placed in the laminate such that the center cut of one ply is placed over the outside edge of thesecond ply. If narrower width mat is used, reverse the second ply should be reversed 180 in the machine direction and laid lay it on top of t
38、he first plyto minimize weight variations.7.3.3 Follow with a 10-mil (0.25-mm) surfacing mat as in 7.3.16.3.1. .7.3.4 Remove the air by rolling over the surface with a serrated metal or plastic roller. Take care not to expel enough resin toraise the glass content above the permissible maximum. The l
39、aminate is considered within the range of allowable levels of resinand glass if the thickness of the laminate is within 0.120 and 0.140 in. (3.05 and 3.56 mm), as described in 6.2.27.2.2.7.3.5 After the lay-up is completed, cover the laminate with a plastic release film to prevent air inhibition or
40、to provide a uniformsmooth glossy surface, or both. Carefully smooth down to remove entrapped air.NOTE 5The application of the release film may be accomplished by any convenient method. It is acceptable to use any convenient method for theapplication of the release film. Regardless of how it is appl
41、ied, it is critical that any entrapped air between the film and the laminate be entirely removed.One method of application is done by previously wrapping the film around a metal rod. Starting at one edge of the laminate, slowly unroll the film fromthe rod, keeping a bead of resin ahead of the rod as
42、 you cross the laminate. Any entrapped air remaining can be removed by rubbing a tongue depressoracross the release film surface. Carefully pull the film taut and fasten at the edges to prevent wrinkling of the film. Placing stops (neoprene has been foundto be suitable) around the edges of the lamin
43、ate and passing a heavy metal roller over the laminate helps to insure uniform controlled thickness.7.3.6 Cure as recommended by the resin manufacturer. The cure schedule shall be reported.7.3.7 Trim edges as required.7.4 Record of Standard Laminate ConstructionRecord the properties of the standard
44、laminate as follows:7.4.1 HardnessDetermine Barcol hardness on the strip as described in 6.2.47.2.4 in accordance with Test Method D2583.7.4.2 Laminate ConditionsVisually examine the laminate. The laminate shall meet Acceptance Level I of Table 1 of PracticeD2563.7.4.3 If the laminate meets the requ
45、irements of this specification, retain the laminate sections for preparation of test specimens.NOTE 6The major criteria for accepting a laminate is thickness and not glass content. If glass content is desired, cut eight 1 by 1 in. specimens fromthe center of the laminate and test in accordance with
46、Test Method D2584.7.5 Individual Test Specimens:7.5.1 Specimens for immersion in test solutions shall be approximately 4 by 5 in. (101.6 by 127 mm), cut from the standardlaminate.7.5.2 Identity of specimens shall be maintained by suitable means.7.5.3 Cut edges and drilled holes, if used for suspensi
47、on, shall be sanded smooth and coated with paraffinated resin.7.5.4 The number of specimens required is dependent on the number of test solutions to be employed, the number of differenttemperatures at which testing is performed, and the number of test intervals. In addition, at least two 4 by 5 in.
48、(101.6 by 127 mm)specimens shall be available for test (see 7.48.4) following the curing period, prior to immersion.8. Procedure8.1 Measurement of SpecimensImmediately following the curing period, measure the thickness of the specimens to the nearest0.001 in. (0.025 mm) at the geometric center of ea
49、ch of the intended 1 by 3 in. (25.4 by 76.2 mm) specimens that will be cut forflexural tests after the completed exposures. Measure the weight of the specimens to the nearest 0.01 g. These thickness and weightmeasurements shall also be used for comparison against thickness and weight measurements after the completed exposures.8.2 ExposureFollowing the curing period, as specified in 6.3.67.3.6, prior to immersion, record a brief description of the colorand surface appearance of the coupons and the color and the clarity of the test solution. Th
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