1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 02 2014 07 16 Editorial Corrected paragraph number in 3.7.9 M. Corley, EU 2011 09 26 Revised / Activated A3 See Summary of revisions (5.0) for details A. Weakley/J. Crist 2007 07 31 Activated J. Robincheck Controlled document at www.MATS
2、Copyright 2014, Ford Global Technologies, LLC Page 1 of 13 PAINT, ONE COMPONENT ELASTOMERIC BASECOAT/CLEARCOAT WSS-M16J20-A1 OVER FLEXIBLE SUSTRATES, EXTERIOR PAINT, TWO COMPONENT ELASTOMERIC BASECOAT/CLEARCOAT WSS-M16J20-A2 OVER FLEXIBLE SUSTRATES, EXTERIOR PAINT, ONE COMPONENT BASECOAT/TWO COMPONE
3、NT CLEARCOAT WSS-M16J20-A3 OVER FLEXIBLE SUSTRATES, EXTERIOR 1. SCOPE The materials defined by these specifications are elastomeric paints, which consist of a basecoat and clear topcoat applied by a baked process. These materials are monobaked. Paint systems may be processed wet-on-wet application a
4、nd monobaked, or paint may be baked between wetcoats. This specification also includes unique colors that require Tri or 4 coat systems. Tricoat colors consist of a pigmented groundcoat followed by a non-hiding midcoat over which is applied a clear or tinted clear. Four coat systems consist of a Bas
5、ecoat, Clearcoat baked then the application of an effect basecoat with a clear or tinted clear. 2. APPLICATION These specifications were released originally for paints used as the final topcoat on exterior trim components made of flexible substrates, such as fascia, bumpers, lip moldings, appliqus,
6、cladding, bodyside moldings. It shall be satisfactory for use over specified primers or over previously baked enamel, as in paint repair or tutone operations. 2.1 LIMITATIONS Bake temperature should not exceed softening temperature of substrate material as agreed upon by Ford Materials Engineering.
7、3. REQUIREMENTS Testing to be used for initial qualification of materials and shall be made on the basis of comparison with approved production material, chosen by the approving materials engineer. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform
8、to the Companys Standard Requirements for Production Materials (WSS-M99P1111-A). 3.2 COMPOSITION Both the basecoat and clearcoat shall contain UV absorbers. The supplier will furnish the specific composition and concentration of the absorbers upon request. 3.2.1 Resin Shall be either a polyester, ac
9、rylic, modified urethane polymer or a polyurethane. Minor amounts of modifiers and/or plasticizers are allowed. ENGINEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copyright 2014, Ford Global Technologies, LLC Page 2 of 13 3.2.2 Pigments Pigments are exterior automotive grade selected to match th
10、e Ford Motor Company master and meet the durability requirements. 3.2.3 Solvents The volatility of solvents will be such that there shall be no paint sagging, roughness or dry spray at specified film thicknesses. Solvents shall be HAPS compliant if it is required by local government regulations 3.3
11、PHYSICAL PROPERTIES LIQUID STATE The following evaluation must be conducted on both the basecoat and clearcoat at application viscosity. Throughout the application viscosity range, material shall be in compliance with local emission regulations. Property variation acceptability as identified below,
12、shall be based on the recorded values of the originally approved production sample as approved by Ford Materials Engineering. This data will be used in developing control plan requirements. 3.3.1 Non-Volatile Content, range Initial sample +/- 4% (ASTM D 1353) 3.3.2 Volatile Organic Compound, range I
13、nitial sample +/- 1% (ASTM D 3960) 3.3.3 Weight per Volume, range Initial sample +/- 0.03 g/ml (ASTM D 1475) 3.3.4 Volume Solids, range Initial sample +/- 2.0% (ASTM D 2697) 3.3.5 Viscosity Report (ASTM D 1200) 3.3.6 Stability No more than 30% (ASTM D 1849) viscosity increase permitted. 3.3.6.1 Shel
14、f Stability, 90 days 3.3.6.2 Accelerated Stability, 60 C, 16 h 3.3.7 Resistivity 0.005 to 2.00 megohms (ASTM D 5682) Volatile solvents and other components affecting electrical conductivity shall be adjusted such that the resistivity at application viscosity shall be within specified limits. ENGINEE
15、RING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copyright 2014, Ford Global Technologies, LLC Page 3 of 13 3.4 PREPARATION OF TEST PANELS 3.4.1 Substrates Flexible polymers and flexible polymer blends, PU, PP, TEO, etc. 3.4.2 Substrate Condition The surface to be coated must be cleaned to ensure the
16、 absence of oil or alkaline residues, fingerprints, corrosion, mold release agents, dirt, moisture, and other foreign materials. Surface energy/resistivity or chemical reaction(s) enhancements (flaming, corona discharge or plasma) and/or addition of conductive materials, necessary to meet the requir
17、ements of this specification, shall be approved by Materials Engineering and noted on ASL 3.4.3 Adhesion Promoter Apply 6-16 m DFT (Dry Film Thickness) of the primer or as otherwise recommended, as specified for the substrate. 3.4.4 Basecoat/Clearcoat Apply basecoat to required dry film thickness by
18、 spray under conditions appropriate for basecoats, and flash as required. Apply clearcoat to required dry film thickness. Bake using appropriate bake schedule. Record paint and oven type used. (As developed by para 3.5). 3.4.5 Design Verification/Initial Qualification Test Requirements as listed in
19、Table 1. 3.4.6 Aging After application of the top coat, all panels shall be aged at least 72 h at 23 +/- 2 C, 50 +/- 5% relative humidity or 16 hours at 45 +/- 1 C before testing. 3.4.7 Cure Process Window Must be developed per paragargh 3.5. ENGINEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Co
20、pyright 2014, Ford Global Technologies, LLC Page 4 of 13 3.5 PROCESS WINDOW DEFINITION - NEW RESIN TECHNOLOGIES ONLY The supplier shall perform a DOE utilizing response surface analysis to determine the Process Window of the system. The three variables to be included in the design are Bake Time, Bak
21、e Temperature, and Film Thickness. An initial screening experiment should be run to determine what level will generate a window which includes testing to failure. This screening experiment should be reviewed with the Materials Engineer to set up the final DOE. Response attributes to the DOE should b
22、e based on the materials tested and should include, but not be limited to: Film Thickness (Para 3.6.3, 3.6.4) Ultraviolet Light Transmittance (Para 3.6.5) Adhesion (Para 3.7.1) Water Immersion (Para 3.7.2) Chipping (Para 3.7.8) Environmental Cycling (Para 3.7.9) High Performance Adhesion (Para 3.7.1
23、0) Report minimum, maximum, and target values for time, temperature, and film thickness. 3.6 FILM PROPERTIES 3.6.1 Color (FLTM BI 109-01, SAE J1545 Three Angle CMC) Shall match the Master Approved Sample color panel or the initial sample as approved by Design Center. 3.6.2 Gloss (FLTM BI 110-01, AST
24、M D 523) Shall match the Master Approved Sample color panel or the initial sample as approved by Design Center. 3.6.2.1 Gloss After Rebake 4 unit decrease max Rebake panel at target bake conditions per Para 3.5. 3.6.3 Film Thickness (ASTM B 487, PELT or equivalent) Targeted Film Thickness: These ran
25、ges are considered to be requirements unless otherwise supported by testing data agreed to by Materials Engineering. Adhesion Promoter 6-16 m Basecoat/Clearcoat 15-30 m /38-50 m Values other than the above Target values shall be defined from process window (Para 3.5). These must be approved by Mater
26、ials Engineer will be specified on the control plan. 3.6.4 Film Thickness, max Not to exceed (ASTM B 487, PELT or equivalent) 230 micrometers With 2 repairs ENGINEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copyright 2014, Ford Global Technologies, LLC Page 5 of 13 3.6.5 Ultraviolet Light Trans
27、mittance For each color, report the minimum film build of basecoat and of clearcoat over epoxy-free spray primer required to meet a maximum light transmission of no more than 0.1% at 360 nm and 0.5% at 400 nm. Fortified (with UV package) clearcoat can be used for this evaluation. The equipment used
28、for this measurement is an integrating sphere spectrophotometer or equivalent. These values shall be used to help determine minimum film thickness for the process window in section 3.5. 3.6.6 General The paint shall bake out to a presentable serviceable film showing no craters, pinholes, seediness,
29、abnormal roughness or excessive metallic mottling. It shall have a reasonable tolerance for ordinary cleaning, and exhibit no dulling or color change when washed with commercially available cleaners. 3.7 RESISTANCE PROPERTIES 3.7.1 Paint Adhesion Less than 5% paint (FLTM BI 106-01, Method D, knife b
30、lade) removal of any paint layer with no complete diamonds removed. Lightly hand sand paint film surface (10 double rubs, moderate pressure) with P600 paper until dull, before scribe operation and checking adhesion. 3.7.2 Water Immersion No blistering, dulling, (FLTM BI 104-01, 240 h) softening, los
31、s of adhesion, and/or any other film failure Adhesion shall be tested according to Para 3.7.1 within 20 minutes after removal from water. 3.7.3 Hydrolysis Resistance Rating 4-5 min (FLTM BI 106-03, 28 days) 3 mm Dia first run panel, 4.7 L Rating 4B or 95% paint retention, no chips 3 mm Dia first run
32、 plus two in-line repairs, 1.4 L only Rating 3B or 93% paint retention no chips 3 mm Dia Chipping is identified as intercoat adhesion loss between any adjoining layers revealing dis-similar colors, scuffing is acceptable. Chipping metrics may be obtained by image analysis software if available. ENGI
33、NEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copyright 2014, Ford Global Technologies, LLC Page 7 of 13 3.7.9 Environmental Cycling, 15 cycles Rating 4-5 min (FLTM BQ 104-07, Procedure 10, 25% Gloss Loss evaluate after 20 h at 23 +/-2 C) No evidence of cracks, no blistering, no change in appea
34、rance or other failure when compared with an original part. After exposure, adhesion testing performance must be met per Para 3.7.1. 3.7.10 High Performance Adhesion Thermal Shock Rating 19 max (FLTM BI 107-05) Alternate Method Resistance Against High Pressure Cleaner 2 mm2 max (FLTM BO 160-04, Meth
35、od B AATCC Evaluation procedure 1: Rating 4 max Gloss Change per ASTM D 523 25% loss max Color Change per FLTM BI 109-01 E 2.0 max After 5 years Florida exposure or 5000 h accelerated weathering: AATCC Evaluation procedure 1: Rating 3 max Gloss Change per ASTM D 523 50% loss max Color Change per FLT
36、M BI 109-01 E 5.0 max 3.9.3.2 Adhesion After Water Immersion 90% adhesion (FLTM BI 104-01, 24 h) retention There shall be no blistering or delamination between any layers of the total paint system. To be evaluated on all exposure intervals. ENGINEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copy
37、right 2014, Ford Global Technologies, LLC Page 10 of 13 3.9.4 Basecoat/Clearcoat Durability Index (DVM 5869 - New Resin Technology Only) (TBC/1250) + (X/2000) greater to or equal to 8 X = TICC if TICC is less than 1.2(TCC) otherwise X = TCC. Method to Determine: TBC Stability of UVA free basecoat/cl
38、earcoat interface) Report TBC (Stability of UVA free basecoat/clearcoat interface) Defined as the time for clearcoat delamination failure for each color. If the color has not failed by 5000 h, TBC = 5000 TICC Time to zero UVA absorbance using isolated clearcoat film. (FLTM AI 103-02, Method A) Prepa
39、re quartz slides with clearcoat only. Adjust clearcoat thickness to obtain a starting absorbance (340 nm region) of 2 2.5 after nominal clearcoat bake. Measure clearcoat thickness in micrometers. Calculate absorbance per micrometer. Correct for absorbance using 100% theoretical mixing of basecoat an
40、d clearcoat UVA. Evaluate clearcoat UVA absorbance using a UV-VIS spectrophotometer. Observe the UV spectrum from 450 250 nm. Determine maximum 340 nm region absorbance on initial (baseline) sample and after 1000, 3000 and 5000 h exposure to Xenon Arc weatherometer (SAE J2527, modified with type “S“
41、 borosilicate inner and outer filters, 0.55 W/m2 radiant exposure. Plot absorbance as a function of exposure time to determine absorbance loss rate (absorbance loss per hour). Calculate TICC (time to zero UVA absorbance using isolated clearcoat film) followed by the equation: 1(absorbance/micrometer
42、)(clearcoat film thickness)/(absorbance loss rate) = hours to clearcoat absorbance equals zero. TCC Time to zero UVA absorbance using full paint system. (FLTM AI 103-02, Method B) Remove clearcoat from the sample (avoid basecoat layer) with a razor or equivalent scraping device or by in-plane microt
43、omy. Using either solvent extraction from the scraping method or direct measurement with a UV microscope and summing the layers, and evaluate clearcoat UVA absorbance using a UV-VIS spectrophotometer. Observe the UV spectrum from 450 250 nm. Determine absorbance on initial (baseline) sample and afte
44、r 1000, 3000 and 5000 h exposure to Xenon Arc weatherometer (SAE J2527, modified with type “S“ borosilicate inner and outer filters, 0.55 W/m2 radiant exposure). Plot absorbance as a function of exposure time to determine UVA loss rate (absorbance loss per hour). Extrapolate UVA loss rate plot to ze
45、ro absorbance. Determine the exposure hours at zero clearcoat UVA absorbance. Report as TCC. ENGINEERING MATERIAL SPECIFICATION WSS-M16J20-A1/A2/A3 Copyright 2014, Ford Global Technologies, LLC Page 11 of 13 3.9.5 Clearcoat Photo Oxidation 2.5 max change in (DVM 5867 - New Resin Technology only) (-O
46、H,-NH / CH) ratio Method: Photochemical stability is determined by a comparison of the chemical state change of the topcoat surface before and after exposure to 5000 h Xenon Arc weatherometer (SAE J2527, modified with type “S“ borosilicate inner and outer filters, 0.55 W/m2 radiant exposure). Evalua
47、te the topcoat photo oxidation stability using Fourier Transform Infrared Photo-Acoustic Spectroscopy (FTIR-PAS). Obtain spectra of the surface layer of topcoat, approximately the top 7 micrometers, experimentally defined as the photo-acoustic sampling depth by modulation at 3 kHz at 3000 wavenumber
48、s in a rapid scan FTIR-PAS experiment or 3 kHz phase modulation in a step scan FTIR-PAS Intensity spectrum, should be a polymer filled with carbon black to at least 50% for a rapid-scan experiment and to at least 65% for a step-scan experiment. Compression set rubber works best. Resolution- laser sa
49、mpling at every second laser crossing, 4000 data points, 8K transform, triangle apodization, phase corrected. Noise (definition) root mean square (rms) noise in 3600 2500 wavelength region based on two carbon black filled polymer background spectra, ratioed to obtain 100% Relative PAS Intensity line. Noise limit 0.75% rms, Relative PAS Intensity. 100% line flat from 4000 2000 wavenumbers, +/- 10% Determine the ratio of the integrated intensity
