Plastic ball density and hollow plastic ball volume calculation formula by Dongguan Jiaji plastic products limited company provides welcome http://www.airsoft-bbschina.com/ plastic hollow plastic ball ball density and volume are as follows: firstly, the plastic ball density instrument need: hydrometer, balance plastic density instrument: preferred usage balance calibration, and then return to zero 10, the grain of 12MMPP plastic ball after drying alcohol wash into balance, weighed 11.5 grams of weight, and then put the plastic ball into the liquid density meter, scale density measuring cup on display is about 0.915, so the proportion of 0.915. PP plastic ball is hollow plastic ball volume formula: first of all we know that the metal ball volume formula is V=4 PI R fand /3, metal ball volume calculation formula and hollow plastic ball volume formula completely The same, assuming that the diameter of a hollow plastic ball is 50mm, then the volume of this hollow plastic ball is: 4*3.14* (50*50*50) /3 the final result is 65416.6667 cubic mm.