1、 FORD LABORATORY TEST METHOD BO 151-02 Date Action Revisions 2001 04 02 Revised Editorial no technical change A. Cockman 2000 02 29 Editorial no technical change A. Cockman 1996 10 25 Printed copies are uncontrolled Page 1 of 4 Copyright 2001, Ford Global Technologies, Inc. LOW TEMPERATURE IMPACT TE
2、ST FOR PLASTICS Application This method is used to determine the low temperature impact resistance of various plastic parts. It was developed to provide a repeatable evaluation of foamed instrument panel assemblies Test Equipment The impact equipment consists of a pendulum arm with the impact ball,
3、and a adjustable milling table capable of holding sample fixtures securely during the test. The milling table should be grooved to hold the sample fixture horizontally or vertically depending on the requirements of the part tested. The pendulum should have the capability to be stopped at any specifi
4、ed angle between 0 and 90 to apply the required impact velocity to the part. The impact ball has a hollow center partially filled with shot to prolong the impact time. The weight of the ball is 4.5 kg; the resultant weight of the ball and pendulum arm is 6.5 kg. A sketch of this equipment is shown i
5、n Figure 1. Engineering drawings on how to construct this equipment are available from: Body Interior Materials Engineering Materials, Fasteners and Corrosion Protection Engineering Advanced Vehicle Technology Sample Fixture The sample fixture consists of a steel plate with a steel substrate that co
6、ntains a sufficient number of original mounting holes to securely hold the test specimen during the test. The length of the substrate and test specimen should not be less than 200 mm. The substrates should be welded to the steel plate so that the impact area of the specimen will be normal to the pen
7、dulum ball face. A minimum of three fixtures should be made in order to allow repeat testing (see relevant Engineering Document for specific number of assemblies to be tested). Convection Oven Capable of maintaining a temperature of 80 +/- 2 C. Cold Box Capable of maintaining temperatures to -40 +/-
8、 2 C. Gloves Insulated, strong fabric. FORD LABORATORY TEST METHOD BO 151-02 Page 2 of 4 Copyright 2001, Ford Global Technologies, Inc. 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 not le
9、ss than 24 hours prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Remove a test specimen from the component with a length sufficient to fit in the sample fixture. The length of the test specimen should not be less than 200 mm. 2. Mount the test specimens
10、 to the steel substrate on the fixtures using the production approved fasteners to form a test assembly and condition for 24 h at 23 +/- 2 C and 50 +/- 5 % relative humidity. The number and location of fasteners should be sufficient to provide a rigid mount. 3. Slide one of the conditioned assemblie
11、s into the grove in the milling stand and slowly lower the pendulum head onto the sample surface. 4. Adjust the vertical position of the milling stand so that the pendulum will fall on the target area of the sample. 5. Adjust the height of the milling stand so that the arm of the pendulum is at 0 de
12、grees (horizontal) while resting on sample surface. 6. Raise the arm to the required number of degrees as stated in the specification and apply the arm brake. 7. Place the assemblies into the oven for 24 hours at 80 +/- 2 C. 8. Using gloves, remove the assemblies from the oven and condition them for
13、 2 hours at 23 +/- 2 C and 50 +/- 5 % relative humidity. 9. Place the assemblies into the cold box for 5 hours at the temperature stated in the relevant Engineering Document. 10. At the end of the cold conditioning, using the gloves, remove one of the assemblies from the cold box and quickly slide i
14、t into the groove in the milling stand. 11. Immediately release the pendulum arm, allowing it to fall and come to rest on the surface of the sample. Steps 10 and 11 must be completed in less than 10 seconds to prevent the surface of the material from warming up. FORD LABORATORY TEST METHOD BO 151-02
15、 Page 3 of 4 Copyright 2001, Ford Global Technologies, Inc. 12. Raise the pendulum to the required number of degrees as stated in the specification and apply the arm brake. 13. Allow the sample to reach room temperature and observe it with the unaided eye from a distance of 300 mm. Rate the severity
16、 of cracking according to the following scale. Rating Observation 0 No visible cracking 1 Slight cracking, hairline cracking that does not extend beyond the impact area. 2 Moderate cracking, cracking that extends beyond the impact area. 3 Severe cracking, the material cracks severely but no pieces h
17、ave broken off the specimen. 4 Catastrophic failure, pieces of the material separate from the specimen. 14. Repeat steps 10 through 13 for each test specimen. Report 1. The report should include: a) Material description b) The number of samples tested c) The test conditions: temperature, angle of pe
18、ndulum, painted or unpainted, etc. d) The mean rating for each sample tested e) Photographs before and after the test Note: For foamed instrument panels the standard conditions include a -35 C test temperature, and an impact velocity of 2.4 m/s (22 pendulum angle), unless otherwise specified in the
19、Engineering Material Performance Specification. Foamed instrument panels shall be tested on the rear edge (nose areas) of the panel. 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 BO 151-02 Page 4 of 4 Copyright 2001, Ford Global Technologies, Inc. LOW TEMPERATURE IMPACT TEST FOR PLASTICS Figure 1
