_______________________________________________________________________ | | | | | | Tenacity | Elasticity | | | (grammes) | (% elongation) | |__________________________________________|___________|________________| | | | | | Nitrocellulose according to Chardonnet | | | | German Patent No. 81,599 | 150 | 23 | | The same after denitration | 110 | 8 | | Denitrated fibre moistened with water | 25 | -- | | Nitrocellulose: Bronnert's German Patent | | | | No. 93,009 | 125 | 28 | | The same after denitration (dry) | 115 | 13 | | The same after denitration (wetted) | 32 | -- | | Natural silk | 300 | 18 | |__________________________________________|___________|________________| 1. Tenacity is the weight in grammes required to break the thread. 2. Elasticity is the elongation per cent. at breaking. The numbers are taken for thread of 100 deniers (450 metres of 0.05 grammes = 1 denier). It must be noted that according to the concentration of the solution and variations in the process of denitration the constants for the yarn are subject to very considerable variation. In regard to the manufacture a number of very serious difficulties have been surmounted. First, instead of drying the nitrated cellulose, which often led to fires, &c., it was found better to take it moist from the centrifugal machine, in which condition it is dissolved (5). It was next found that with the concentrated collodion the thread could be spun direct into the air, and the use of water as a precipitant was thus avoided.