1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions Ver 3 2008 07 08 N-STATUS Replaced by WSS-M4G252-E2 M. Mehandru, FNA 1986 08 10 Revised CAO1-RD537896 1984 01 31 Released CAN1-DR505583 WP 3948-a Page 1 of 9 SEALER, VINYL BASED - HEAT CURING - EXTRUDABLE -
2、ESB-M4G252-A SPRAYABLE - ABRASION RESISTANT - PAINTABLE NOT TO BE USED FOR NEW DESIGN 1 SCOPE The material defined by this specification is a vinyl based, extrudable, sprayable, sag resistant, abrasion resistant, paintable, heat cure sealer. 2. APPLICATION This specification was released originally
3、for material used for sealing hem flanges on body closure panels, interior body seams in floor pan areas, exterior body coach joints, lap joint seams and underbody chip resistance. This material can be sealer gun extruded and spray applied to body electrocoat primed surfaces. Recommended material cu
4、re schedules are specified in para 5.3. A 0.50 mm wet film thickness is recommended for abrasion resistance. 3. REQUIREMENTS 3.1 QUALITY CONTROL Suppliers must conform to the requirements of Ford Quality System Standard Q-101, with control charts and process data analyzed according to Ford Continuin
5、g Process Control and Process Capability Improvement Manual. Additionally, a Control Plan is required for material source approvals. 3.2 CONDITIONING All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5% relative humidity for 24 h p
6、rior to testing and tested under the same controlled conditions. 3.3 INFRARED SPECTROPHOTOMETRY Ford Motor Company, at its option, may conduct infrared analysis of material/parts supplied to this specification. The spectra established for initial approval shall constitute the reference standard and
7、shall be kept on file at Ford. All samples shall produce spectrographs that correspond to the reference standard when tested under the same conditions as those specified on the master spectra. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 2 of 9 3.4 SOLIDS, min 95% (ASTM D 2834, exc
8、ept heat at 102 +/- 1 C for 3 h in a mechanical convection oven. Save sample for next test, para 3.5) 3.5 ASH, max 40% (Based on the Solids weight) . Place the crucible containing the solids residue in a cool muffle furnace. . Slowly heat to and maintain at 760 +/- 30 C for 1 h. . Cool crucible in a
9、 desiccator and weigh. 3.6 WEIGHT PER VOLUME 1.3 - 1.6 kg/L (ASTM D 816) The weight tolerance for any one supplier shall be +/- 0.02 kg/L, based on the recorded weight of his original approved production sample. 3.7 VISCOSITY (FLTM BV 3-1, 1.32 mm orifice, 280 kPa) 3.7.1 As Received Viscosity 20 - 4
10、5 s (Unagitated - Method “A“) 3.7.2 Aged Viscosity 80 s (Material aged in closed container for 72 h at 41 +/- 1 C, Unagitated - Method “A“) Final approval of a specific material viscosity for production shipments shall be made by the affected manufacturing activity. In all cases, the viscosity shall
11、 be within specification limits. 3.8 BRIDGING, max 6.4 mm Test Method: . Apply a 13 mm diameter material bead over the 6.4 mm diameter holes shown in the sketch below. . Condition the text fixture with material bead for 15 min at 23 +/- 2 C, then bake fixture at the minimum bake schedule per para 5.
12、3. . Measure the amount of material sag through hole. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 3 of 9 BRIDGING TEST FIXTURE 3.9 SAG RESISTANCE 3.9.1 Horizontal, max 6.4 mm 3.9.2 Vertical, max 6.4 mm 3.9.3 Inverted No loss of material Test Method: . Apply a 3 x 30 x 200 mm ribbo
13、n of material along the center line of three electrocoated panels prepared per para 5.2. . Scribe panels to mark the initial material location. . Position the panels with the material in the attitude above for 1 h. . Immediately after conditioning, place panels in an oven to cure material at the min
14、imum bake schedule per para 5.3. Maintain panels in the specified attitude during baking and cooling. . Allow the panel to cool to 23 +/- 2 C. . Determine the sag by measuring the material movement below the scribe mark. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 4 of 9 3.10 ADHE
15、SION Shall not be peeled off in a continuous film at any thickness. Test Method: . Apply 6.4 - 0 mm tapered material ribbon on two electrocoated panels prepared per para 5.2. See sketch below. . Subject one test panel, to the minimum bake schedule and the other test panel to the maximum bake schedul
16、e identified per para 5.3. . Condition panels after baking at 23 +/- 2 C for 1 h minimum. . Evaluate adhesion by cutting a 25 mm wide strip across the tapered ribbon. Using the tip of a squared spatula, lift the material at both the thin and thick film edges then attempt to hand peel material at 90
17、from substrate. . Save test panels for Heat Stability Test, para 3.10, and Corrosion Resistance Test, para 3.11. TEST PANEL ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 5 of 9 3.11 HEAT RESISTANCE TEST No evidence of blistering, cracking, charring or other deleterious effects Test
18、Method: . Examine the test material prepared for Adhesion Test, para 3.9, for any of the above conditions. 3.12 CORROSION RESISTANCE No corrosion or adhesion loss Test Method: . Expose the panels prepared in para 3.10 for 240 h in the salt spray cabinet described per ASTM B 117. . Condition the test
19、 panels after exposure at 23 +/- 2 C for 24 h. . Evaluate material adhesion as described in para 3.9. Observe for any evidence of corrosion originating directly under material. 3.13 MANDREL BEND TEST No cracking or adhesion failure (FLTM BV 22-1, material bake schedule per par 5.3, heat age test spe
20、cimen 14 days at 70 +/- 1 C before test) 3.13.1 Test at 23 +/- 2 C 3.13.2 Test at - 29 +/- 1 C 3.14 CRACK RESISTANCE, min 5,000 cycles (FLTM BV 15-1, except bake an additional set of panels for 15 min at 135 +/- 1 C for normal and aged test, use substrate identified per para 5.3) 3.15 COMPATIBILITY
21、WITH PRODUCTION PAINTS No tackiness, staining, discoloration or other deleterious effects on topcoats. 3.15.1 240 h weatherometer exposure (Equipment described in FLTM BO 1-1) 3.15.2 96 h dry ultraviolet light exposure (Equipment described in FLTM BV 7-2) ENGINEERING MATERIAL SPECIFICATION ESB-M4G25
22、2-A WP 3948-b Page 6 of 9 Test Method: . Prepare test panels per FLTM BV 53-8, Procedure “A“, except apply primer on three panels only, use a primer bake schedule of 135 +/- 1C for 8 min metal temperature and a topcoat bake schedule of 130 +/- 1 C for 10 min metal temperature. Apply current producti
23、on paints as identified by the Body and Chassis Product Engineering Office. . Condition painted panels at 23 +/- 2 C for 72 h. . Subject one primed and one unprimed panel with topcoat to each exposure listed above. Retain extra panel as control. . After exposure, examine test panels and compare to t
24、he control panel. 3.16 SHEAR ADHESION, min Min Bake Max Bake (FLTM BV 1-6, substrate per Exposure Exposure para 5.2., 3 mm bondline 310 N 800 N thickness material bake schedules per para 5.3) 3.16.1 As received material 3.16.2 Aged material (Material aged in closed container for 72 h at 41+/- 1 C) 3
25、.17 HARDNESS, DUROMETER “A“ 75 - 85 (ASTM D 2240) Test Method: . Apply enough material into a container (such as an ointment tin) to give a 6 mm thickness slab. . Bake material at 135 +/- 1 C for 30 min. . Condition test sample at 23 +/- 2 C for 4 h, then check instantaneous material hardness. 3.18
26、ABRASIVE None Test Method: . Dilute a 1 g sample of the material with 1 g of M14J167 special spirits or equivalent, and mix thoroughly. . Rub a portion of the diluted material 100 times between 2 pieces of flat, clean plate glass. The appearance of scratches on the glass plate shall be considered fa
27、ilure. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 7 of 9 3.19 SPRAYABILITY Shall be suitable for use in the airless spray equipment designated by the B&AGO Paint Operation Activity. 3.20 ABRASION RESISTANCE The coating shall protect body substrates from stone abrasion when subjec
28、ted to 5500 cm3 of gravel per SAE J400, and corrosion after exposure to 1000 h salt spray per ASTM B 117. There shall be 100% coating retention to all substrates after the abrasion test with no corrosion extending more than 3.0 mm from scribed or abraded areas after salt spray exposure. Test Method:
29、 . Prepare panels with spray applied sealer to a minimum wet film thickness of .050 mm. . Scribe an “X“, with approximately 100 mm legs, through to base metal on the top portion of all prepared panels. . Allow panels to set for 72 h at 23 C, then check coating adhesion before environmental exposure.
30、 Evaluate the adhesion by cutting a 25 mm wide ribbon along the bottom edge of the panels. Grasp the ribbon and attempt to peel at 180. Acceptable adhesion requires a minimum 440 N/m peel strength or 90% minimum cohesive failure at film thicknesses greater than 0.50 mm. . Subject the bottom portion
31、of the 0.50 mm coated panels to 5500 cm3 of gravel. Examine panels for coating retention loss. . Expose the abraded panels to 1000 h salt spray. . After salt spray exposure, allow the panels to dry at 23 C for 48 h and then re-evaluate adhesion as described in the third paragraph above. Remove the c
32、oating from the lower half of the test panels and along the scribed area. Examine for evidence of corrosion and corrosion extension from the scribe. 3.21 STORAGE STABILITY The material shall be stored at temperatures below 41 C away from all sources of heat and sunlight. Heat greatly accelerates agi
33、ng. Under these storage conditions, the shelf life of the material shall be 3 months. When these materials are stored at temperatures below 23 C, they shall be conditioned at room temperature prior to application. Adequate conditioning permits the material to obtain its optimum application propertie
34、s. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 8 of 9 3.22 QUALITY Shall be a smooth, homogeneous mixture free from foreign materials and properties detrimental to normal production operations. 3.23 FUNCTIONAL APPROVAL Materials being evaluated for initial specification shall be s
35、ubjected to a production trial. Functional trial results should be available to Design and Materials Engineering prior to material approval and release. 3.24 SUPPLIERS RESPONSIBILITY All materials supplied to this specification must be equivalent in all characteristics to the material upon which app
36、roval was originally granted. Prior to making any change in the properties, composition, construction, color, processing 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 Supp
37、lier shall notify Purchasing, Toxicology and the affected Materials Engineering activity of the proposed changes and 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 i
38、mposed by law, regulations or Ford, apply to the materials addressed by this document. The restrictions are defined in 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
39、: Materials defined by this specification must have prior approval by the responsible Materials Engineering activity. 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
40、 Supplier shall submit to the affected Materials Engineering activity its own laboratory report to the specification (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 Mate
41、rial Approved Source List. 5. GENERAL INFORMATION: The material data included herein is for information only and is not a requirement for the supplier. ENGINEERING MATERIAL SPECIFICATION ESB-M4G252-A WP 3948-b Page 9 of 9 5.1 MECHANICAL CONVECTION OVEN The mechanical oven(s) used to cure the materia
42、l shall be capable of obtaining 205 C metal temperature on body steel (0.8 - 0.9 mm thickness within 8 - 10 min. 5.2 SUBSTRATES Nominal panel dimensions are 0.8 x 100 x 300 mm. Electrocoat primed steel panel: Prepared per ESB-M2P4 performance specification. Use current production paints as identifie
43、d by the Body and Chassis Electrical Product Engineering Office. 5.3 MATERIAL CURE SCHEDULES 5.3.1 Minimum (includes two bakes): First Bake: 8 min at 135 +/- 1 C metal temperature Second Bake: 8 min at 120 +/- 1 C metal temperature plus 3 min at 130 +/- 1 C metal temperature 5.3.2 Maximum 20 min at 177 +/- 1 C metal temperature 5.4 COLOR Gray or as specified by B&AGO Paint Operation Activity
