FORD FLTM BV 115-1-2000 FLEXIBILITY OF SEALERS (Replaces FLTM BV 015-01 FLTM EU-BV 015-01).pdf

1、 FORD LABORATORY TEST METHOD BV 115-01 Date Action Revisions 2000 12 11 Revised Editorial no technical change A. Cockman 1993 07 27 Printed copies are uncontrolled Page 1 of 6 Copyright 2000, Ford Global Technologies, Inc. FLEXIBILITY OF SEALERS Application This procedure is used to determine the fa

2、tigue life (adhesion and cohesion) characteristics of cured sealers for typical coach joint applications. Apparatus and Materials Required Flexing Fixture (See Figure 1) Used to flex the test panel from 0 - 4 +/- 0.5 mm outward from normal position, at a rate of 350 +/- 50 cycles per minute as measu

3、red at the coach joint. The test panel A is clamped at both ends (B1 and B2 ) and flexed by means of a motor driven eccentric cam (F) and connecting rod (E). The flexing distance X can be adjusted by means of the eccentric cam. Mechanical Convection Oven, Temperature Recorder, Thermocouples Accordin

4、g to FLTM BV 150-05. Test Panel Assemblies Steel body skin panel, for dimensions see Figure 2. Electrocoated surfaces prepared after spot welding according to the technique outlined in FLTM BI 120-01, using a released material. Alternative: Panels can be electrocoated by use of normal production pro

5、cess. Magnifying Glass 5X - flash light type. Template (disc-ended) 12 mm diameter. Naphtha Lint Free Cloth 360 Abrasive Waterproof Sanding Paper Deionized Water Chamois Cloth FORD LABORATORY TEST METHOD BV 115-01 Page 2 of 6 Copyright 2000, Ford Global Technologies, Inc. Conditioning and Test Condi

6、tions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure A. Normal Flexibility (6 assemblies re

7、quired) 1. Take 6 prepared test assemblies, and cool to 23 +/- 2 C. 2. Apply a bead of sealer 3 - 4 mm diameter to the joint of the test assembly. Using the template, mold the sealer into the assembly to provide a slightly concave ribbon over the joint. Care must be taken to prevent excessive remova

8、l or wipe-off of material at either end of the joint. 3. Spray coat the assemblies with currently released production primer wet on wet. After 10 minutes flash off time bake as follows: (a) 3 assemblies in accordance with FLTM BV 150-05, Table 2 minimum curing cycle - Phase 1; or as specified by the

9、 relevant engineering document. (b) 3 assemblies in accordance with FLTM BV 150-05, Table 2 maximum curing cycle - Phase 1; or as specified by the relevant engineering document. Record the assembly temperature by placing a thermocouple on the seam, as shown in sketch, but not in the material under t

10、est. 4. After conditioning the assemblies for 1 hour at 23 +/- 2 C, wet sand the coach joint surfaces as follows: Water sanding of assemblies is performed with No. 360 waterproof paper. The operation is performed in one direction only. After water sanding prime coated assemblies are rinsed with deio

11、nized water and wiped with chamois leather. Then each assembly will be wiped in the sanding direction with a lint-free rag wetted with naphtha and subsequently dried for half an hour at 23 +/- 2 C. Note: Step 4 may be omitted if agreed upon by the affected Materials Engineering Office. FORD LABORATO

12、RY TEST METHOD BV 115-01 Page 3 of 6 Copyright 2000, Ford Global Technologies, Inc. 5. Spray the assemblies with a light colored production enamel and bake as follows: (a) For assemblies prepared in para 3a - in accordance with FLTM BV 150-05, Table 3, minimum curing cycle; or as specified by the re

13、levant engineering document. (b) For assemblies prepared in para 3b - in accordance with FLTM BV 150-05, Table 3, maximum curing cycle; or as specified by the relevant engineering document. Record the assembly temperature as described in para 3. 6. Condition the assemblies for a minimum of 4 hours a

14、t 23 +/- 2 C. Mount an assembly in the flexing fixture as shown in Figure 1 with the flange pointing downwards and centered in the middle of the clamps (B1 and B2). The clamp (D) must be 6 mm away from the underside of the panel. 7. After clamping the assembly in place, deflect the panel to the maxi

15、mum of 4 mm, or according to the relevant Engineering Specification, by moving the eccentric cam by hand and inspect and note any pin holes or small cracks. 8. Start the flexing machine and continue the test for the total number of cycles required by the relevant Engineering Specification, or until

16、failure occurs. On completion of every 500 cycles, interrupt the test with the assembly in the extended position and using the magnifying glass, examine the joint for metal failure and/or sealer adhesive or cohesive failure. 9. Repeat procedure as outlined in para 6 - 9 using the other assemblies. E

17、valuation: Sealer failure is defined as a crack or number of cracks, including those initiated by pin holes, that have a total length in excess of 12 mm. Cracks which occur only in the paint coat and do not penetrate the sealer shall not be considered a sealer defect. All test assemblies must pass t

18、he required number of flex cycles specified in the material specification. B. Aged Flexibility Test (6 assemblies required) 1. Follow Procedure A, para 1 - 5, and age the assemblies in the oven at 70 +/- 2 C for 2 weeks. 2. Mount and test the assemblies as described in Procedure A and follow Procedu

19、re A, para 6 - 9. Evaluation: As described under Procedure A. FORD LABORATORY TEST METHOD BV 115-01 Page 4 of 6 Copyright 2000, Ford Global Technologies, Inc. C. Normal Flexibility without Paint Overlay (6 assemblies required) 1. Take 6 prepared test assemblies and cool to 23 +/- 2 C. 2. Apply bead

20、of sealer 3 - 4 mm diameter to the joint of the test assembly. Using the template, mould the sealer into the assembly to provide a slightly concave ribbon over the joint. Care must be taken to prevent excessive removal or wipe-off of material at either end of the joint. 3. Subject assemblies to the

21、following heat curing cycles: (a) 3 assemblies in accordance with FLTM BV 150-05, Table 2, Minimum Curing Cycle - Phase 1; or as specified by the relevant engineering document. (b) 3 assemblies in accordance with FLTM BV 150-05, Table 2, Maximum Curing Cycle - Phase 2; or as specified by the relevan

22、t engineering document. Record the assembly temperature by placing a thermocouple on the seam, as shown in drawing, but not in the material under test. 4. Continue testing as outlined in Procedure A, para 6 - 9. Evaluation: Sealer failure is defined as a crack or number of cracks, including those in

23、itiated by pin holes, that have a total length in excess of 12 mm. All test assemblies must pass the required number of flex cycles specified in the material specification. D. Aged Flexibility without Paint Overlay (6 assemblies required) 1. Follow Procedure C, para 1 - 3, and age the assemblies in

24、the oven at 70 +/- 2 C for 2 weeks. 2. Continue testing as outlined in Procedure A, para 6 - 9. Evaluation: As described under Procedure C. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BV 115-01 Page 5 of 6 Copyright 2000, Ford Global Technologies, Inc. Figure 1 FORD LABORATORY TEST METHOD BV 115-01 Page 6 of 6 Copyright 2000, Ford Global Technologies, Inc. Figure 2