1、FORD LABORATORY TEST METHOD EU-BP 052-01 Date 2001 0822 1994 02 28 OZONE RESISTANCE OF THE TYRE SIDEWALLS Action Revisions Revised Editorial - no technical change A. Cockman Application This method is used to assess the ozone resistance of passenger vehicle tyre sidewalls under static conditions. Ap
2、paratus Required Ozone Generator and Test Chamber Capable of maintaining ozone concentration of 50 p.p.h.m. +/- 5 (by volume) and a temperature of 38 +/- 1 OC with the necessary measuring and control devices, as described in FLTM EU BP 1 O1 - 01. The nominal ozonised air velocity over the surface of
3、 the specimen must be 60 cm per second. Clamping Device As shown in Figure B. Magnifying Glass x2. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 OC and 50 +/- 5 % relative humidity for not less than 24 h pri
4、or to testing and tested under the same conditions unless otherwise specified. Procedure 1. Cut 3 test specimens radially from the sidewall of the tyre under test. The bead wire must not be removed (see Figure A) Note: The part of the specimen adjacent to the shoulder of the tyre must not exceed 10
5、mm thickness, and when necessary the outer face of the part must be ground or cut to give the required maximum thickness. Ensure that the temperature of the ground surface does not exceed 40 OC during the grinding operation. All cut and ground surfaces must be coated with an elastic ozone resistant
6、compound. Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BP 052-01 2. Place the specimens in the test fixture, ensuring that they are a minimum of 20 mm apart (see Figure B). 3. Condition specimens for 72 burs in the dark at 20 +/- 2 OC, in an atmosphere substantially fr
7、ee of ozone. 4. Immediately place the fixture into the ozone chamber maintained at 50 p.p.h.m. +/- 5 of ozone, a temperature of 38 +/- 1 OC and a nominal ozonised air velocity over the surface of the specimen of 60 cm per second, for a period of 70 hours. Evaluation After exposure, remove the specim
8、ens retained in the fixture and examine. Classification of Ratina Interpretation O No checking or cracking visible under 2X magnification. 1 Checking or cracking not visible to the unaided eye but visible at 2X magnification. 2 Small cracks visible to the unaided eye. 3 Medium size cracks or checks
9、visible to the unaided eye. 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. Page 2 of 3 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST MET
10、HOD EU-BP 052-01 OZONE RESISTANCE OF THE TYRE SIDEWALLS Sketch “A Material: non-ferrous metal or wood provided with an ozone resistant cover The specimen length (Y) is limited by the height of the tyre sidewalls and will be chosen as the maximum value as stated below: Dimension X Dimension Y 90 80 7
11、0 140 125 110 Note: In cases where no specimen with the side length (Y) of 11 O mm can be prepared out of the sidewalls, the maximum possible specimen length must be chosen. The dimension X is taken equivalent to the proportion 0.65 (X) to 1 .O0 (Y). Page 3 of 3 Copynght02001, Ford Global Technologies, Inc
