ISO 3865:2020 pdf download.Rubber, vulcanized or thermoplastic一Mlethods of test for staining in contact with organic material.
6 Test pieces
6.1 Rubber test pieces
Rubber test pieces shall be rectangular in shape, of uniform thickness and preferably cut from sheet
2 mm ± 0,2 mm thick. The minimum dimensions shall be:
— for method A: 12 mm x 25 mm;
— for method B.1: 25 mm x 150 mm:
— for method B.2: 3 pieces with a total mass of 5 g ± 0,2 g;
— for method C: 12 mm x 25 mm.
Test pieces for method C shall be cut from samples prepared in accordance with .&3.
Test pieces may also be cut from finished products, in which case they may be cleaned of extraneous
contamination before test with a 2 % non-alkaline soap solution.
6.2 Metal or plastics panels for methods A and B
The dimensions of metal or plastics panels shall meet the requirements specified in J. or 82. but otherwise are not critical.
Panels shall be coated with a material to be agreed between purchaser and supplier. Unless otherwise specified, a white acrylic-based stoving enamel shall be used. This lacquer shall be dried in the oven (5J,) for 30 mm at 125 °C and tests shall commence between 24 h and 48 h after drying. If other times are used, these shall be stated in the test report.
6.3 Test piece preparation for method C
6.3.1 General
A white or light-coloured non-discolouring rubber veneer, of a composition to be agreed between purchaser and supplier, shall be applied under pressure to a sheet of the test rubber. The veneer shall either be vulcanized with the test rubber or be applied as a paint on a previously prepared sheet of vulcanized or thermoplastic rubber.
As agreed between the interested parties, test pieces may be taken from finished products with lightcoloured veneered or lacquered surfaces, such as white tyre sidewalls. The method of construction and the sample thickness shall be mentioned in the test report.6.3.2 Vulcanized test pieces and veneers
All mixing shall be carried out in a thoroughly cleaned mixer, preferably in accordance with Iso 2393. The rubber shall be sheeted out to a thickness of 2,0 mm ± 0,2 mm, and protected on both sides by an inert material, such as starched cambric fabric or polyethylene sheet, until tested. A test piece shall be cut out to the required mould dimensions.
The rubber veneer shall be calendered to a thickness of 0,5 mm ± 0,05 mm and stiffened on at least one side with a protective aluminium sheet.
At the time of coating, one protective layer shall be removed from both the test rubber and the veneer, and the two exposed surfaces pressed firmly together, ensuring that the aluminium sheet remains on the external side of the rubber veneer. Pressure may be applied by a platen press or by rollers.
The composite body, including the aluminium sheet, shall be moulded and vulcanized in a platen press, taking care that the veneer and aluminium sheet are situated at the bottom side of the mould. The conditions of vulcanization shall be included in the test report. The protective surface on the veneer shall be left until used.
6.3.3 Lacquered test pieces
Test pieces shall be immersed in a white, non-staining lacquer at a depth of 25 mm. The test pieces shall be hung on a suitable rack and dried. After drying, they shall be immersed a second time in the lacquer, then dried until the surface is non-tacky.
Instead of lacquer, a paste prepared of the unvulcanized veneer in a suitable solvent (volume ratio 1:6) may be used. The procedure shall be the same as for lacquer.
Aluminium foil dipped in the lacquer/paste may be used as a blank.ISO 3865 pdf download.