1、 ENGINEERING MATERIAL SPECIFICATIONMaterial Name Specification NumberDate Release No. Release/Revision1990 02 01 C01031532 Released C. E. Herriott concurred J. SchultWP 3948-a Page 1 of 13PAINT, CLEAR COAT IN BASE COAT/CLEAR COAT WSK-M32J125-ASYSTEM, BAKING, EXTERIOR TOP COAT1. SCOPEThe material def
2、ined by this specification is a clear coat of a basecoat/clear coat system required to provide the best exterior qualitymetallic finish. It consists of a thermosetting acrylic clear top coatresin and Ultra Violet light absorber package to improve weatherdurability, combined with a physical drying me
3、tallic base coat, whichare applied wet on wet and concurrently stoved. It shall be suitable forspray application.2. APPLICATIONThis specification was released originally for a material used as aclearcoat for a wet on wet final colour top coat system on automotivebodies and other exterior parts. It s
4、hall be satisfactory for use overspecified primers, primer surfacers or over baked enamel, as in repairor tu-toning operations.3. REQUIREMENTS3.1 STATISTICAL PROCESSSuppliers must conform to the requirements of Ford Quality SystemStandard Q-101. A mutually acceptable Control Plan as describedtherein
5、 is required for material/source approval. Appropriatestatistical tools must be used to analyze process/product data sothat variation in the final product is continually reduced.3.2 INFRARED SPECTROPHOTOMETRY AND/OR THERMAL ANALYSISFord Motor Company in its option, may conduct infrared and/orthermal
6、 analysis of materials/parts supplied to thisspecification. The IR spectra and thermograms established forinitial approval shall constitute the reference standard andshall be kept on file at the designated Material Laboratory. Allsamples shall produce IR spectra and thermograms that correspondto the
7、 reference standard when tested under the same conditions.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 2 of 133.3 ULTRA VIOLET SPECTROGRAPHIC ANALYSIS(FLTM tbd)All approved materials shall contain with Initial Sample Reportan UV-spectroscopic analysis. This shall be recorded and fil
8、edby Quality Control or relevant Testing Laboratories of the FordMotor Company.Subsequent material UV-spectroscopic analysis shall correspond tothe data of the Initial Sample.3.4 CONDITIONINGAll panels shall be aged for 72 h at 23 +/- 2 C or 16 h at 43 +/-2 C before testing for resistance properties
9、 unless otherwisespecified.In the event of differences between test resu lts, the resultsafter ageing at room temperature shall govern.All tests according to this specification shall be performed in acontrolled atmosphere of 23 +/- 2 C and 50 - 65 % relativehumidity if not otherwise specified.3.5 FL
10、ASH POINTThe flash point shall conform to the safety regulationsapplicable to the plant and/or country where the material shallbe used.3.6 COMPOSITION3.6.1 ResinEssentially an acrylic and melamine formaldehydesynthetic resin system capable of meeting thisspecification requirements.3.6.2 Pigment None
11、The colourless clear coat shall not change the basecoat colour but give enhanced appearance, colour,lustre and performance to meet the requirements of thisspecification.3.6.3 SolventThe volatile portion shall contain sufficient activesolvents to give satisfactory adhesion.The properties of solvents
12、in the volatile portionshall be so arranged that the clear coat will level outsatisfactory on spray application. The volatility ofthe solvents is to be so chosen that the clear coatwill give a dry film thickness up to 45 micrometrewithout sagging and with satisfactory freedom fromroughness or dry sp
13、ray.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 3 of 133.6.4 Base CoatClear coat meeting this specification shall be totallycompatible with the Ford Engineering approved base coatWSK-M32J124-A or approved equivalent materials. Afterbaking to the required conditions the base coat/cl
14、earcoat system shall present an exterior topcoat finish ofthe highest quality.3.6.5 Specific CompositionWhen it is necessary to obtain specific data regardingmaterial formulation, it is understood that thesupplier will furnish such data on request.3.6.6 Ultra Violet Light AbsorberThe clear coat shal
15、l contain sufficient amounts ofsuitable Ultra Violet light absorber packages. Thesewill be selected by the supplier to provide long termdurability.3.6.7 Special DataAll initial and batch submissions must indicatedensity, non-volatile content, and volume solids of thematerial as supplied on the sampl
16、e report.3.7 PHYSICAL PROPERTIES3.7.1 Non-volatile Initial Sample(FLTM BI 102-01) +/- 1,0 %Minimum solid content 32,0 %unless otherwise releasedThese solid limits apply to clear coats adjusted to aviscosity of 35 s Ford Cup 3, at 25 C (FLTM BI 111-01).Solvents may be specified by vendor but shall be
17、 FordProduct Engineering Approved prior to use.3.7.2 Density Initial Sample(ASTM D 1475) +/- 0,02 g/mL3.7.3 Viscosity(FLTM BI 111-01, Ford Cup 3, 25 C)Package Viscosity Initial Sample+/- 5 sENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 4 of 133.7.4 Shelf StabilityDuring a storage of
18、3 months at room temperature, theclear coat as received shall not gel or show anyturbidity upon standing and must be free from settlingwhich cannot be dispersed by normal agitation. Theviscosity of the material shall not increase in excessof 20 s (FLTM BI 102-03, Ford Cup 3, 25 C)3.7.5 Solvent Emiss
19、ions max 0,096 kg/L(ASTM D 3960)This requirement is as deter mined by the United StatesEnvironmental Protection Agency Reference Method #24but is only applicable to materials used in the USA.3.7.6 Volume Solids Not less than(FLTM BI 154-02) Initial Sample3.8 PREPARATION OF TEST PANELS(FLTM BI 103-02
20、, Method B, b)3.8.1 SubstrateFord Engineering Approved Standard Steel Test Panelscoated with Ford Engineering approved zinc phosphateand prepared in accordance with Ford ManufacturingStandard U-MA18004/U-MA18005 or Equivalent.3.8.2 Cathodic ElectrocoatFord Engineering approved current production mat
21、erials.Apply the above primer to a minimum dry film thicknessof 25 micrometre and bake as defined in relevantmaterial specification.3.8.3 Primer SurfacerFord Engineering approved current production material.Apply the above primer to a minimum dry film thicknessof 30 micrometre, and bake as defined i
22、n relevantmaterial specification.Do not sand the primer surface.3.8.4 Base CoatApply approved base coat agai nst specification WSK-M32J124-A (reduced to spray viscosity as specified byvendor) to a dry film thickness of 15 - 20 micrometre.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page
23、5 of 133.8.5 Clear CoatApply clear coat under test (reduced to spray viscosityas specified by vendor) to a dry film thickness of 35 -45 micrometre.Minimum total dry film thicknessBase coat and clear coat 50 micrometre3.8.6 Flash-Off Time1 minute between base and clear coat application3.8.7 Baking Cy
24、clesBase coat and clear coat baked simultaneously3.8.7.1 Standard Bake Bake 10 minutesat 130 C metaltemperature.3.9.1 Colour3.9.2.1 Gloss3.9.2.2 Gloss after re-bake3.10.4 Hardness3.11 Resistance properties includingAdhesion3.12 Weathering3.13.1 Repair colour match.3.8.7.2 RebakeStandard Bake and the
25、n bake 10 minutes at140 C metal temperature.3.9.1 Colour3.9.2.2 Gloss after rebake3.13.2.3 Intercoat adhesion3.8.7.3 In Plant RepairEnamels containing acid cat alyst (item3.13) Bake 10 minutes at 100 C metaltemperature.3.9 APPEARANCE3.9.1 Colour(FLTM BI 109-01)Colour of clear coat film shall remain
26、water whiteafter all baking cycles described in item 3.8.7.Colour of base coat and clear coat shall match therelevant approved Master Appearance Sample (MAS) Panel.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 6 of 133.9.2 Gloss(FLTM BI 110-01, 20 deg glossmeter)3.9.2.1 Standard Bake
27、, min 903.9.2.2 Rebake GlossA decrease of not more than 4 units glossis permitted when panel is rebaked peritem 3.8.7.23.9.3 LevellingThe surface of the material under test shall be equalto or better than current approved production materialfor smoothness when applied and baked under identicalcondit
28、ions.3.9.4 HoldoutThere shall be no evidence of dulling or change ofimage clarity when enamel colour coat is applied oversanded and unsanded primer surfacer, and no differencein gloss of the colour coat between sanded and unsandedprimer. There shall be no prominence of sand scratches.Tests shall be
29、made at both maximum and minimum bakecycles.3.9.5 Distinctness of Image tbd(FLTM BI 110-03)3.10 FILM PROPERTIES3.10.1 General AppearanceThe clear coat shall bake out to a presentable,serviceable film showing no craters, pinholes orabnormal roughness.It shall not show excessive metallic mottling in t
30、hebase coat.It shall have a reasonable tolerance for ordinarycleaning and show excellent polishing characteristicswhen wheel polished with wide range of variouscompounds and cleaners.3.10.2 Wet on Wet CompatibilityThe material must be compatible for wet on wetapplication.3.10.3 Film Thickness(FLTM B
31、I 117-01)Base coat plus clear coat, min 50 micrometreCoating must be sufficient to meet all performancerequirements of this specification.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 7 of 133.10.4 Final Hardness3.10.4.1 Penetration, full system,age 72 h at 23 +/- 2 CTukon, min 6.0 K
32、HN(FLTM BI 112-02)3.10.4.2 SurfacePencil, min H(FLTM BI 151-01)3.10.5 PolishingThe coating surface shall be capable of being sandedand polished, or polished only. No noticeable change ingloss or appearance, except for a minimum of polishinglines shall result. Deep polishing lines or swirl marksare n
33、ot acceptable.Hardness and polishing characteristics shall be suchthat air-borne dirt dried in the film and dry sprayareas or other surface defects can be removed bysanding and polishing.After sanding with 600 grit paper lubricated withmineral spirit and then wheel polished with a mediumgrit compoun
34、d there shall be no noticeable change inappearance between the polished and unpolished area.3.10.6 UV Absorber CrystallizationStore 1 L of the clear coat as supplied in a beaker for24 h at - 10 C and then allow the temperature toincrease to 20 C. Do not stir. No turbidity nor anytendency to crystall
35、ization nor any other visiblechange of the material permitted.3.11 RESISTANCE PROPERTIES3.11.1 Paint Adhesion(FLTM BI 106-01, Methods A & B)Method A No chippingMethod B Grade 0No chippingThere shall be no flaking of clearcoat from thebasecoat.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b
36、Page 8 of 133.11.2 Water Resistance 240 h(FLTM BI 104-01)No blistering, softening, dulling, colour change and/orloss of adhesion.Adhesion shall be tested according to item 3.11.1Method B.3.11.3 Salt Spray Resistance min 480 h(FLTM BI 103-01)No rust spots, blistering, chipping, peeling, glossloss, ad
37、hesion loss or rust creepage more than 3 mmfrom scribed line.Adhesion shall be tested according to item 3.11.1Method B.3.11.4 Water and Soap Spot Resistance(FLTM BI 113-01)3.11.4.1 Water Spotting AATCC Ratingmax discolouration 4 - 53.11.4.2 Soap Spotting AATCC Ratingmax discolouration 4 - 53.11.5 Ac
38、id Spot Resistance(FLTM BI 113-05, Base/Clear, 30 minutes)Max discolouration None3.11.6 Xylene Wipe ResistanceNo dulling, softening or other undesireable effectsafter the enamel, which has been aged 72 h, is rubbed10 times in a circular motion with a wad of cheeseclothwetted with Xylene and allowed
39、a 30 minute recoveryperiod.3.11.7 Stone Chip Resistance, max Rating 3(FLTM BI 157-04)3.11.8 Cold Check Resistance, 10 cycles No cracking or(FLTM BI 107-02) dulling3.12 WEATHERING3.12.1 Florida Exposure, 12 Months AATCC Rating 4(FLTM BI 160-01)5 deg south, directweathering inland)3.12.2 Accelerated,
40、min AATCC Rating 4(SAE J1960)Radiant Exposure tbd GJ/m2ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 9 of 13Accelerated Weathering is only to be considered if forEngineering concurred special reasons no Floridaresults are available. Under such circumstancescomparative testing only is
41、 allowed against materialsof known Florida stability with identical chemical typeof resin.In case of differences in the test results of Floridaexposure and the accelerated weathering the results ofthe Florida exposure shall prevail.Prior to examination the exposed samples must becleaned with approve
42、d soap solutionAfter exposure in accordance with 3.12.1 and 3.12.2washed but unpolished exposure samples shall show aminimum degree of dulling, change of colour anddistinctness of image with both standard and catalyzedrepair paint when compared to an unexposed retainedmaster.Both original and repair
43、 shall alter in colour, toneand gloss to the same degree in the same direction.Only the slightest colour change is permitted. Thesesamples shall show no colour change, or irridescence inexcess of specified AATCC rating (AATCC Grey Scale forEvaluating Change in Colour, 10 step).Gloss after exposure s
44、hall be minimum 70 units (20degree glossmeter, FLTM BI 110-01).The film shall be free from dirt and mildew. Unsoiledpanels shall be preferred to those soiled by exposure.No chalking is permitted.The panels shall be completely free from evidence ofcracking, checking, rusting, blistering, and peeling.
45、One small area of the exposed panel shall be slightlypolished with a current polish followed by a 24 h waterimmersion test of the complete panel according to FLTMBI 104-01. The panel is then again compared to theunexposed panel. Only a slight colour change ispermitted on the polished as well as on t
46、he unpolishedarea of the panel.3.12.3 After Weathering Adhesion(FLTM BI 106-1, Method C)No loss of adhesion of clear coat or total paint systempermitted.ENGINEERING MATERIAL SPECIFICATIONWSK-M32J125-AWP 3948-b Page 10 of 133.12.4 After Weathering Water ResistanceAfter Florida exposure and/or acceler
47、ated weathering,test specimens shall be tested according to FLTM BI104-01 for 24 hours. Adhesion shall be tested accordingto item 3.11.1.3.12.5 New Vendors and Resin FormulationsSubmissions of the above shall require weatherresistance over an extended period up to 5 years. Prioruse without Product E
48、ngineering approval is notpermitted.Sufficient panels shall be initially sent to Florida toallow interim evaluation after each 12 months duringthis exposure period.Long term Florida exposure panels prior to expo sureshall have 1/3 of the surface polished with a surfacegrinding compound. Using cotton
49、 wool the surface shallbe rubbed 10 times under medium pressure in a straightlongitudinal line. Wipe excess compound away usingclean towel.Grinding compound as recommended by MaterialsEngineering.3.12.6 ReflectanceMeasure and record reflectance of Florida test panelsas a graph prior to and after each year of exposure upto 5 years using spectrophotometer or other suitableequipment.Recommended equipment is Zeiss Spectrophotometer TypeDMR 21 with reflectance attachment.3.12.7 Weather Exposure Control PanelsFor all exterior weather exposure tests to thisspecification, control panels shall be
