1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2005 09 28 Activated B. Harris Printed copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 1 of 7 PAINT, POWDERED, THERMOSETTING ACRYLIC WSS-M70J12-A 1. SCOPE The material defined within this specification is for an exte
2、rior thermosetting acrylic powder coating applied to metal parts. The powder coating shall provide good initial appearance with adequate durability and corrosion resistance. 2. APPLICATION This specification was released originally as an acrylic powder topcoat finish on exterior parts providing exce
3、llent weathering resistance with specified color and gloss. It is intended for electrostatic spray or fluidized bed application over such substrates as cold rolled steel, galvanized, zinc die cast, aluminum and stainless steel parts. 3. REQUIREMENTS After a technology is approved to this specificati
4、on, every color must be evaluated to determine the effects of specific color or physical properties and must comply with the Exterior Parts Painter Approval Process per AVP-T113-015. Must meet the performance requirements of WSS-M2P180-B and appropriate Subsystems Design Specification on appropriate
5、 test plaques, with the following exceptions which take precedence: 3.9.1 Adhesion Part “A“ added. 3.9.5 Thermal Shock No high pressure cleaner required. 3.10 Weathering - Florida (5 year) and 5000-hour weatherometer for New Resin Technology. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Materi
6、al Suppliers and part producers must conform to the Companys Standard For Production Materials (WSS-M99P1111-A). 3.2 COMPOSITION Powder coatings must be Thermosetting Acrylics. Each will be appropriately formulated to meet the UV Transmittance and Weatherability requirements as defined in 3.8.2 and
7、3.10. ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 2 of 7 3.3 MATERIAL CONTROL CHARACTERISTICS Physical characteristic evaluations are to be submitted with each lot, by the paint supplier to the paint applicator, as
8、a quality Certificate of Approval. 3.3.1 Particle Size and Distribution, target Identified by supplier (ASTM D 5861) on initial submission 3.3.2 Specific Gravity Identified by supplier (ASTM D 5965, Method A or B) on initial submission +/- 0.05 maximum. 3.3.3 Gel Time Identified by supplier (ASTM D
9、4217-02 176 C) on initial submission +/- 6 s. 3.3.4 Hardness Identified by supplier (ASTM D 1474, after aging 72 h, min above 20 C) on initial submission Record value at target film thickness and bake conditions. Coating shall be sufficiently cured after baking so that it can meet the polishing requ
10、irements of Para 3.8.3. 3.4 PROCESSABILITY Processing characteristics must be submitted and archived with the initial approval package. 3.4.1 Processing Matrix Production representative electrostatic powder guns shall be used. Report fluidizing air pressure, electrostatic voltage, feed and conveyanc
11、e (or equivalent) air pressures, and powder flow in oz (lb) / min. 3.4.2 Fluidization Characteristics Evaluate the fluidization of the powder at different fluidization air pressures, particle size distributions, and humidity levels. The fluidization system must be production representative. 3.4.3 In
12、clined Flow Test (ASTM D 4242) Determine the time versus temperature profiles for flow and sintering properties as mutually agreed on between supplier and affected Materials Engineering Office. 3.4.4 Heat-up Rate Supplier shall demonstrate the effect that heat-up rates will have on appearance of the
13、 final coating as defined in 3.7. Also, supplier will demonstrate whether an interrupted bake, as may occur at breaks or shift change, affects appearance attributes. ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 3 of
14、7 3.4.5 Storage Stability, 4 weeks Fill a 250 ml glass jar to 2/3 capacity with test powder. Carefully place a floating cover and a 100 gram weight on the surface of the powder and seal with a lid. Place the container into a 30 C water bath noting the time and date. Immerse the container only to the
15、 level of the powder inside. At one-week intervals, the container is removed from the water bath, blotted dry, and allowed to cool to room temperature. To evaluate physical stability, remove the lid, 100 gram weight and floating cover from the surface of the powder. Replace the lid and gently rotate
16、 the container and note the free flowing nature of the powder. If the powder is not free flowing or contains lumps, the lid is removed and the powder probed with a small spatula to determine the degree of compaction or sintering. The test is ended when the powder is not free flowing or agglomerates
17、may not be easily broken. To determine chemical stability, evaluate gel time, inclined plate flow, and / or cured film properties and compare to initial values. The test is ended when any property has become unacceptable. 3.5 PREPARATION OF TEST PANELS Substrate: Current production phosphated cold r
18、olled steel or galvanized steel, zinc die-cast or AA 3003, H-14 aluminum. Record all information. Substrate approvals will be documented in the Approved Source List. Electrocoat: Current production cathodic electrocoat applied at 20 23 microns, baked 10 minutes at 182 C metal temperature (MT). Recor
19、d electrocoat and oven type used. Pretreat: Zinc phosphate per WSS-M3P1-D shall be used if steel and aluminum are being processed concurrently. Dual phase Zinc phosphate may also be used where production aluminum content exceeds 7%. Powder Coat: Apply powder topcoat at 51 - 102 microns or the optima
20、l performance thickness as recommended by the supplier and bake to parameters defined in Para. 3.6. Record the powder coat material and application (whether a basecoat or clearcoat) and oven type used. Clearcoat: If required, apply wet clearcoat to 38 76 microns or the optimal performance thickness
21、as recommended by the supplier and bake to parameters defined in Para. 3.6. Record clearcoat and oven type used. ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 4 of 7 3.6 PROCESS WINDOW DEFINITION NEW PAINT TECHNOLOGIE
22、S ONLY The supplier shall perform a Design of Experiments (DOE) (Response Surface Analysis is recommended) to determine the process window of the control and candidate materials. Variables included in the design are bake time, bake temperature and film thickness and particle size distribution. An in
23、itial screening experiment should be conducted to determine what levels should be tested for the variables / parameters. This screening experiment should be reviewed with the materials engineer to set up the final DOE. Responses to the DOE will be based on the materials tested and will be chosen fro
24、m the tests listed within the specification. Minimal critical testing required: Initial UV transmittance at various film thickness, initial cross hatch adhesion, thermal shock, condensing humidity, chemical resistance and stone chip (SAE J400 and Erichsen grit blast). The materials engineer will use
25、 this information to determine acceptable plant processing conditions. Minimum, maximum and target values derived in Para 4.2. Process Window characteristics must be submitted and archived with the initial approval package. 3.7 APPEARANCE Appearance panels will be prepared using standard paint proce
26、ssing parameters as defined in 4.2. Consideration should be given to an application process window DOE to assess impact of key process variables / parameters on final appearance. 3.7.1 Color (FLTM BI 109-01) Shall match the Master Appearance Sample approved by the Design Center. 3.7.2 Wave Scan DOI,
27、 min Equal or better than (Byk Gardner Wave Scan) Master Appearance Standard. 3.7.3 Gloss As specified by letter (FLTM BI 110-01) suffix to the Styling As released by Corporate Design: color number. (Use as a guide) A: 20 Glossmeter, min 92 B: 60 Glossmeter 76 - 84 C: 60 Glossmeter 66 - 74 D: 60 Glo
28、ssmeter 58 - 66 E: 60 Glossmeter 47 - 53 F: 60 Glossmeter 33 - 38 G: 60 Glossmeter 17 - 23 H: 60 Glossmeter 7 - 13 J: 60 Glossmeter 4 - 6 K: 60 Glossmeter 2 - 4 L: 60 Glossmeter 0.5 - 2 ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technolo
29、gies, LLC Page 5 of 7 3.8 FILM PROPERTIES Film properties panels will be prepared using standard paint processing parameters as defined in 4.2. 3.8.1 Film Thickness E-coat: 20 25 microns (ASTM D 1186) Powder: 51 102 microns Clearcoat: 38 76 microns 3.8.2 Ultraviolet Light Transmittance (DVM 5886 v2,
30、 Requirement PA-0149) Max light transmission through powder (applied at minimal performance thickness as recommended by the supplier) shall be no more than 0.1% at 360 nm and 0.5% at 400 nm at time zero and 2500 h Accelerated Weathering according to paragraph 3.10.2. The equipment used for this meas
31、urement is an integrating sphere, Lamda 18 spectrophotometer or equivalent. 3.8.3 Polishing Shall be capable of being sanded with 1200 grit sandpaper and polished in accordance with current plant processes to minimize orange peel or to remove defects. No noticeable change in gloss or appearance exce
32、pt for a minimum of swirl marks is permitted. Deep polishing lines or swirl marks are not acceptable. 3.9 RESISTANCE PROPERTIES Resistance properties panels will be prepared using standard paint processing parameters as defined in 4.2. 3.9.1 Adhesion Grade 0, no chipping (FLTM BI 106-01, Part A and
33、B) or flaking permitted. 3.9.2 Xylene Rub, Cure Test, min 90% gloss retention (FLTM BN 107-01/ FLTM BI 110-01) Perform 10 double rubs, wetted cheesecloth. 3.9.3 Abrasion Resistance No wear through (FLTM BN 108-02, CS10, 1000 g) topcoat permitted. Conduct test to 1000 cycles per 25 microns film thick
34、ness. 3.9.4 Thermal Shock No discoloration or (FLTM BI 107-05) adhesion loss. ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 6 of 7 3.10 WEATHERING Weathering properties panels will be prepared using standard paint pro
35、cessing parameters as defined in 4.2. Data derived from Natural Weathering takes precedence over Accelerated Weathering as the Umpire Method. Acrylic powder chemistries are more susceptible to weatherometer UV attack. After exposure (Para 3.10.1), panels must meet Para 3.10.3 requirements. 3.10.1 Na
36、tural Weathering Florida Exposure (SAE J1976, Procedure A) New Pigment 2 years required New Color (known pigments / resins) 1 year required New Resin Technology 5 years required 3.10.2 Accelerated Weathering (SAE J1960, 0.55 W/m2Irradiance, Borosilicate Inner and Outer Filters) New Pigment 2000 h, a
37、pplicable resin New Color (known pigments / resins) 1000 h required New Resin Technology 5000 h required 3.10.3 Testing After Exposure (FLTM BI 160-01, B) 3.10.3.1 Appearance After 1 year Florida exposure or 1000 h accelerated weathering, there shall be no visual color change and 10% maximum gloss l
38、oss. There shall be no blistering, cracking, peeling or micro checking. After 2 years Florida exposure or 2000 h accelerated weathering; . 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
39、or 5000 h accelerated weathering: . AATCC Evaluation procedure 1: Rating 3 max . Gloss Change per ASTM D 523 50% loss max . Color Change per FLTM BI 109-01 E 5.0 max ENGINEERING MATERIAL SPECIFICATIONWSS-M70J12-APrinted copies are uncontrolled Copyright 2005, Ford Global Technologies, LLC Page 7 of
40、7 3.10.3.2 Adhesion After Water Immersion (FLTM BI 104-01) 16 h (FLTM BI 106-01, Part B) Grade 2, max There shall be no blistering or delamination between any layers of the total paint system. To be evaluated on all exposure intervals. 4. GENERAL INFORMATION The information given below is provided f
41、or clarification and assistance in meeting the requirements of this specification. Contact the Design Responsible Materials Engineering Activity for the substances currently used in production. 4.1 PAINT SYSTEMS (potential paint systems usage for production) 4.1.1 Electrocoat primer (baked) + powder
42、 topcoat (baked) 4.1.2 Electrocoat primer (baked) + powder topcoat (baked) + clearcoat (baked) Clearcoat selection based on chemical and weathering resistance of color coat. 4.2 TOPCOAT PROCESSING CONDITIONS AND TEST REQUIREMENTS MATRICES Process window (Para 3.6) will be used to define targets, hig
43、h / max, and low / min. Target film thickness is defined as the optimal thickness range as defined by the supplier, min and max is target range +/- 20%. These values will be used to establish the conditions in Table 1 and shall be used to prepare panels for all tests in Para 3.7, 3.8, 3.9, 3.10. TAB
44、LE 1: TOPCOAT PROCESSING CONDITIONS REQUIRED FOR PARA 3.7, 3.8, 3.9 AND 3.10. Conditions Powder Bake Bake Filmbuild Time Temperature 1 Low Min Min 2 Low Max Max 3 Target Target Target 4 High Min Min 5 High Max Max Note: Control testing panel requirements to be chosen at discretion of approving materials engineer. 4.3 EXPLOSION HAZARD These materials should be used in a closed system specifically designed for their use because of the possibility of dust explosion present in powdered material.
