Rubber Compound: Raw Rubber Washed, Dried and Mixed with Sulphur on Hot Rolls (Thorpe, 1913)

How a rubber works of 1913 turned raw rubber into a 'mixing' ready for shaping and curing: the rubber is washed between corrugated rolls under running water, dried on racks, broken down on hot smooth rolls until plastic, and then worked together with fillers and finally sulphur into an even dough. Very few goods were made of rubber and sulphur alone: pure mixings cost too much and are too soft for most uses. Unknown: which fillers, and how much of them and of sulphur. Thorpe names the kinds of materials but gives no mixing. Source: T. E. Thorpe, Dictionary of Applied Chemistry vol. IV (1913), pp. 586-587. Picture: Fig. 1, a washing machine.