(rums, Resins, 



296 



[Oct. 190o. 



for wearing apparel. This is one of the very important uses of rubber and is respon- 

 sible for the consumption of a great part of the fine Para imported. Here probably 

 plantation rubber would be of great use, being pale in colour, clean and free from 

 offensive odour, provided that the lasting properties of the rubber are not injured 

 in the preparation. 



Fabrics are coated with rubber in two ways. The rubber may be made into 

 dough by masticating and mixing with sulphur and other ingredients and spread 

 in this condition on the fabric by means of heated rollers ; or the rubber, sulphur 

 and mixings are made into a paste with a rubber solvent, and this paste is spread on 

 the fabric by the aid of rollers, and the solvent dried off by passing the fabric over 

 plates heated by steam. 



For vulcanisation, the heat cure, using steam or water, is usually adopted. 

 The machinery necessary for spreading rubber is heavy and costly, the rolls are 

 of polished steel about 2 feet in diameter, and each machine has at least three, 

 and may have four, rollers arranged vertically above each other on horizontal 

 axes. The fabric is rolled over the top roller, round between this and the second, 

 an even tension being thus given to the cloth, and finally it emerges between 

 the second and third. The rubber as dough or paste is spread on to the fabric 

 from the face of the third roller, as the cloth passes between it and the second. 

 There are machines for spreading simultaneously on both surfaces of the cloth, 

 and many different details in the actual mechanism of the spreading. The rolls 

 are called calanders, and the machines are very similar to the calandering machines 

 used in paper manufacture. 



31. There are many forms of India-rubber goods which cannot justly be 

 placed under any of the three previous clauses, but which deserve some mention 

 here, especially as they are made for the great part from rubber of the finest 

 quality, and for which plantation-grown rubber is at present never used. 



CUT-THREAD AND SHEET. 



32. Out-thread is the name given to rubber in the form of thread, or strands 

 of square cross section cut from solid sheets of rubber already vulcanised. This 

 rubber thread which when fine is woven into elastic webbing, is all of the best 

 possible quality, and special nerve, elastic and keeping properties are demanded. 

 The amount of labour which is actually spent on the rubber would make it a false 

 economy to use untried cheap rubber, and makers of cut-thread will not use at 

 present plantation rubber for this process. Each manufactory has its own special 

 methods for actually cutting the thread, and details of the machines are jealously 

 guarded as secrets. I was, however, admitted in several instances and saw rubber 

 being actually cut into threads by multiple scissors and knives, the thread after- 

 wards being powdered and spooled and wound into hanks. The details of the 

 cutting I shall not attempt to describe. 



Cut-sheet is made from large blocks or cylinders weighing about half a ton, 

 the cutting being done by a blade four to six feet long, which is rapidly oscillating 

 with a saw-like movement, and which is well lubricated with water or soap and 

 water. Sheets cut in this way show a fine striation due to the little ridges which 

 mark the progress of the knife at each stroke along the block or cylinder. A good 

 tobacco pouch is usually made from this cut-sheet and shows the appearance 

 described. The most interesting feature in making cut-thread or sheet to the man 

 interested in rubber is the process of preparation of the rubber into blocks ready 

 for the knife. The utmost care must be taken in the preliminary washing, and if 

 any grit be in the raw rubber the washed sheet is subjected to a final cleaning 

 between smooth and hardened steel rollers which crush the grains of sand which 

 are then washed out. The rubber is then well masticated and mixed with sulphur 



