BS ISO 2781:2018,Rubber, vulcanized or thermoplastic – Determination of density.Now you can download BS ISO 2781:2018 pdf file.The size is 1.6M.
BS ISO 2781:2018 specifies two methods of test for the determination of the density of solid vulcanized and thermoplastic rubbers
Such determinations are of importance in the control of the quality of a rubber compound and in the calculation of the mass of rubber required to produce a given volume of material.
BS ISO 2781:2018 does not cover the determination of the relative density of rubber, which is the ratio of the mass of a given volume of rubber to the mass of an equal volume of pure water at a given temperature.
2 Normative references
ISO 18899: 2013, Rubber-Guide to the calibration of test equipment.
ISO 23529, Rubber – General procedures for preparing and conditioning test pieces for physical test methods.
8 Time-interval between forming and testing
8.1 Unless otherwise specified for technical reasons, the following requirements for time-intervals shall be observed.
8.2 For all test purposes, the minimum time between forming and testing shall be 16 h.
8.3 For non-product tests, the maximum time between forming and testing shall be 4 weeks and, for evaluations intended to be comparable, the tests, as far as possible, shall be carried out after the same time-interval.
8.4 For product tests, whenever possible, the time between forming and testing shall not exceed 3 months. In other cases, tests shall be made within 2 months of the date of receipt by the customer of the product.
11 Procedure
11.1 Preparation of sample
If fabric is attached to, or embedded in, the sample, it shall be removed before cutting out the test pieces. The method of removal shall preferably avoid the use of a swelling liquid, but, if necessary,a  suitable non-toxic liquid of low boiling point may be used to wet the contacting surfaces. Care shall be taken to avoid stretching the rubber during the separation from the fabric, and the liquid, if used, shall be allowed to evaporate completely from the rubber surfaces after separation. Cloth-marked surface shall be made smooth by buffing in accordance with ISO 23529.