ISO 1795-2017 pdf free download

ISO 1795-2017 pdf free download.Rubber, raw natural and raw synthetic Sampling and further preparative procedures
Caoutchouc, naturel brut et synthétique brut — Méthodes d’échantillonnage et de preparation ultérieure.
accordance with the hot-mill method of ISO 248-1, where specified. Take portions from the material subjected to the determination of volatile-matter content sufficient to carry out the other chemical tests that may be required.
Certain rubbers tend to stick to the rolls during the hot-mill method. If sticking occurs, the oven method of ISO 248-1 shall he used. Even if the oven method is used for the determination of volatile-matter content, the rubber shall still be dried by the hot-mill method prior to carrying out chemical tests. If this Is not possible, then the test samples shall be taken directly from the laboratory sample. When thermogravimetric methods in ISO 248-2 are used for the determination of volatile-matter content, the test samples shall be taken directly from the laboratory sample.
If the procedure given in f,2 is followed, the combined laboratory sample may be prepared by blending together material remaining from each determination of volatile-matter content so that a combined laboratory sample of 250 g ± 5 g is formed. Blend the individual pieces together using the procedure described in 7.3.2.2.
7.3.2 Mooney viscosity
7.3.2.1 Preparation without milling This is the preferred procedure.
Cut a test sample of appropriate thickness from the laboratory sample. Prepare two test pieces in the manner specified in ISO 289-1 and measure the Mooney viscosity in accordance with ISO 289-1. The test pieces shall be as free as possible from air and pockets that may trap air against the rotor and die surface. Rubber in chip or pellet form shall be evenly distributed above and below the rotor.
7.3.2.2 Preparation with milling
In some cases, it may be necessary to mass the rubber on a mill prior to testing (for a particular rubber type, the appropriate evaluation procedure specifies whether milling is necessary). Milling shall be carried out in accordance with the following procedure.
Take a test sample of rubber of about 250 g ± 5 g from the laboratory sample. Pass the test sample 10 times between the surfaces of the mill rolls with the nip set at 1,4 mm ± 0,1 mm and with the mill roll surface temperature maintained at 50 °C ± 5 °C (see, however, the special procedures for butadiene rubber, ethylene-propylene-diene rubber and some types of hutadiene-acrylonitrile rubber given below). In passes 2 to 9 inclusive, double the rubber upon itself. On the tenth pass, sheet the rubber without doubling. Prepare two test pieces in the manner specified in ISO 289-1 and determine the Mooney viscosity in accordance with ISO 289-1,
For butadiene rubber (BR), and for ethylene-propylene-diene rubber (EPDM) of low Mooney viscosity (<35), the mill roll surface temperature shall be 35 °C ± 5 °C.ISO 1795-2017 pdf free download.