1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions Rev 02 2011 07 29 N Status Replaced by WSS-M8P5-B1/B2 C. McComb, NA 2000 05 18 Revised Editorial no technical change APC 1984 09 12 Released CL01-DR526249 Page 1 of 5 METALLIZE PLASTIC PARTS - REFLECTORS ESB
2、-M5P8-A NOT TO BE USED FOR NEW DESIGN 1. SCOPE This specification defines the performance requirements and processing procedures for functional first surface coatings on the reflector parabola (third surface to exterior). The coatings on the thermoplastic or thermosetting plastic parts involve vapor
3、 deposition of metals in a vacuum. 2. APPLICATION This specification was released originally for the coatings used on reflector parabolas of composite type aerodynamic headlamps. See para 5 for definitions of procedures and materials found to produce acceptable metallized coatings. 3. REQUIREMENTS 3
4、.1 APPEARANCE 3.1.1 All parts shall be free from any objectionable blemishes on the reflective surface. A blemish is defined as the presence of any one or combination of the following: Orange peel, weld marks, crazing, etc. unless otherwise designated on the drawing or visual standards. 3.1.2 All pa
5、rts shall be finished off smoothly; flash, gates, etc. removed. All visible surfaces shall be highly polished unless otherwise specified. 3.1.3 Photometry (Engineering Test Procedure SM-22) Sample must meet requirements of para 5.1.1 and 5.1.2 of SM-22. 3.2 ADHESION 3.2.1 Adhesion to Plastic (FLTM B
6、I 6-1, Method “B“) No chipping, flaking or loss of adhesion to the base plastic. ENGINEERING MATERIAL SPECIFICATION ESB-M5P8-A Page 2 of 5 3.2.2 Scratch Test Scratch the finished surface with a sharp instrument, 16 lines/25 mm in one direction. Scratch at right angles to the first lines, forming com
7、plete squares. Repeat the adhesion test as listed in para 3.2.1. 3.2.3 Intercoat Adhesion (FLTM BI 6-2) The coating system shall show satisfactory adhesion of all coats to one another. 3.3 INITIAL HARDNESS The finish shall be sufficiently cured at time of packing to withstand normal handling and shi
8、pping without marring. 3.4 RESISTANCE PROPERTIES 3.4.1 Resistance Requirements Parts tested as outlined in para 3.4.2 shall conform to the following: . The finished part shall not warp, craze, crack, check or sustain a dimensional change greater than the tolerances specified on the engineering drawi
9、ng. . Bright metallic surfaces shall show no indications of oxidizing, peeling, blistering, tarnishing or other discoloration. . Colored surfaces shall show no indications of checking, blistering, loss of adhesion, chalking and only slight fading. 3.4.2 Resistance Tests 3.4.2.1 Resistance to Cycling
10、 (FLTM BO 15-1) 3.4.2.2 Resistance to Heat 3 h at 80 +/- 2 C or as specified on the engineering drawing. 3.4.2.3 Resistance to Humidity 120 h at 98 +/- 2% relative humidity and 38 +/- 1 C. ENGINEERING MATERIAL SPECIFICATION ESB-M5P8-A Page 3 of 5 3.4.2.4 Resistance to Salt Spray, min 48 h (ASTM B 11
11、7) 3.4.2.5 Water Immersion, min 96 h (FLTM BI 4-1) 3.4.2.6 Weathering Resistance Florida Exposure (Miami Area) 12 months at 45 facing south. Test reflector as a finished assembly. Weatherometer Test* 400 h (FLTM BO 1-1) *In the event of differences between accelerated weathering and Florida exposure
12、, the Florida exposure shall govern. 3.5 SUPPLIERS RESPONSIBILITY All materials supplied to this specification must be equivalent in all characteristics to the material upon which approval was originally granted. Prior to making any change in the properties, composition, construction, color, process
13、ing or labeling of the material originally approved under this specification, whether or not such changes affect the materials ability to meet the specification requirements, the Supplier shall notify Purchasing, Toxicology and the affected Materials Engineering activity of the proposed changes and
14、obtain the written approval of the Materials Engineering activity. Test data, test samples and a new code identification are to be submitted with the request. Substance restrictions imposed by law, regulations or Ford, apply to the materials addressed by this document. The restrictions are defined i
15、n Engineering Material Specification WSS-M99P9999-A1, unless a different suffix (e.g., A2 or A3) is specified on the engineering document for the application. 4. APPROVAL OF MATERIALS Materials defined by this specification must have prior approval by the responsible Materials Engineering activity.
16、Suppliers desiring approval of their materials shall first obtain an expression of interest from the affected Purchasing, Design and Materials Engineering activity. Upon request, the Supplier shall submit to the affected Materials Engineering activity its own laboratory report to the specification (
17、test results, not nominal values), the material designation and code number, and test specimens for Ford evaluation. Upon approval, the material will be added to the Engineering Material Approved Source List. ENGINEERING MATERIAL SPECIFICATION ESB-M5P8-A Page 4 of 5 5. GENERAL INFORMATION This infor
18、mation is for direction of the user and is not a requirement for the supplier. The following procedure and materials have been found to produce a metallized coating which will meet requirements of this specification. Parts should be metallized as soon after molding as is practical. The surface shall
19、 be free from dirt, lint, mold release agents, fingerprints and any other contaminants. 5.1 STRESS RELIEVE Thermoplastic parts with intricate patterns of varying wall thicknesses may be susceptible to crazing or cracking from residual stress. Parts shall be tested as described below before coating i
20、s applied to determine necessity for stress relieving. If parts show cracking, crazing, or checking, they must be stress relieved according to a cycle agreed upon by the supplier and the responsible product engineering office. 5.1.1 Test for Residual Stress Expose parts to three complete cycles as l
21、isted in FLTM BO 15-1. Examine parts for cracking, crazing, or checking. If not evident, stress relieving is not required. 5.2 BASE COAT Apply base coat material to surface of part on area to be metallized. Part must be clean and dry. Thickness as specified on the Engineering Drawing or applicable E
22、ngineering Material Specification. 5.3 BAKE Heat part in oven with good air circulation at the time-temperature cycle recommended by the supplier of the base coat material for the type of plastic involved. 5.4 METALLIZE Apply a coating of metal, to the area specified, by evaporation in a vacuum. Con
23、ditions will be determined by film thickness, opacity, luster, etc., desired. 5.5 TOP COAT Apply, over the metallized surface, a coating of clear top coat material. Film thickness shall be as specified on the Engineering Drawing or applicable Engineering Material Specification. ENGINEERING MATERIAL SPECIFICATION ESB-M5P8-A Page 5 of 5 5.6 BAKE Heat in oven with good air circulation as recommended by supplier of top coat material. Note: Similar to Manufacturing Standard P-139.
