BS 1970:2012 pdf free.Hot water bottles manufactured from rubberand PVC – Specification.
BS 1970 The full thickness tensile properties shall be determined on the hot water bottlewithout removing any embossing or ribbing from the test pieces. The strengthshall be calculated as the maximum load in newtons at break divided by thewidth of the central parallel portion of the dumb-bell used.
NOTE The width is normally taken from measurements made on the cutter.
A minimum of three test pieces (preferably five) shall be taken in two directionsfrom the hot water bottle. lf the embossing or ribs are unidirectional, the testpieces shall be taken so that their major axis is parallel to the embossing or ribsand at right angles to the embossing or ribs. lf the embossing or ribs are notunidirectional, take test pieces in two directions at right angles to incorporatethe possible maximum and minimum strength.
Tensile tests for rubber hot water bottlesTensile stress-strain properties before ageing
When tested in accordance with 6.4.1, the tensile strength shall be not less than22.5 N/mm width and the elongation at break shall be not less than 500%.Tensile stress-strain properties after ageing
After ageing the test pieces in an air circulating oven for (168± 2) h at atemperature of (70 ± 1)°C in accordance with BS ISO 188, the tensile strengthshall be not less than 17.0 N/mm width and the elongation at break shall be notless than 425%.
After continuous immersion of the test pieces in distilled water of a temperatureof (70 ± 1) C for (95 ± 1) h, the tensile strength shall be not less than 21.0 N/mm width and the elongation at break shall be not less than 425%.Thetest pieces shall be measured before immersion in the water.After the immersion period, the test pieces shall be stored in water at (23± 2) °C for aperiod of not less than 16 h and not more than 96 h before testing.
When tested in accordance with 6.4.1, the tensile strength shall be not less than12 N/mm width and the elongation at break shall be not less than 150%.
After ageing in an air circulating oven as described in BS ISO 188 for (168± 2) hat a temperature of (100 ± 2) C and, when tested in accordance with 6.4.1, thetensile strength shall be not less than 12 N/mm width and the elongation atbreak shall be not less than 150%.After Soxhlet extraction with water of the test pieces over(168 ± 2) h using anapparatus in accordance with BS 2071, the tensile strength of the test piecesshall be not less than 12 N/mm width and the elongation at break shall be notless than 150% when tested in accordance with 6.4.1.BS 1970 pdf download.