September i, 1906 ] 



THE INDIA RUBBER WORLD 



383 



RESULTS OBTAINED FROM BELTS. 



^1^1 li; |)oiiiilaiity of automobil 



I veliicles has iiuule itself 



conimerce that would ai 



Hilarity of automobiles as pleasure and business 

 If felt in many hranclies of 

 appear in no niaj- related to 

 the motor car industry. This is true, for examijle, 

 of makers and users of conveyor belts. So much rubber is 

 used for motor vehicle tires, and .so rapidlj' is the consump- 

 tion increasinjj. that crude rubber has attained a much lii.u;her 

 priced level than would, a few years ago, have seemed possi- 

 ble. Tliis has had, of course, an eftect ujjon the conveyor 

 belt trade, and a short time ago the large users of these de- 

 vices were rendered uneasy by an intimation from manufac 

 turing sources that the^■ might expect a slialp juni]) in prices 

 in the near future. 



It is conceded that rul)ber makes the best conve\iir l)elt 

 for .many purposes, though cotton duck answers very well 

 for some work. The term " rubber belt, " by the way, does 

 not alwaj's mean exactly- vehat it says. Rubber alone has 

 not the necessary tensile strength and is too elastic to admit 

 of its being used for belting, .so it is combined w'ith strong 

 canvas duck of the thickness to make a belt of the reipiired 

 size. There are many modifications of the rubber belt, even 

 for conveyor purposes. 



Opinions as to which is the best belt for conveying pur- 

 poses are almost as many as there are users and makers. 

 .•\ bolt that would do good .service in one place might prove 

 unsuited to another, even where the material to be moved is 

 the same. There is realU- no way of determining in ad- 

 vance what the life of any conveyor belt will be; it must be 

 tried out on the work for which it was intended. Each belt 

 is, and must be, subject to conditions peculiar to itself. No 

 two are identical no more than any two men are absolutely 

 alike. Two belts of the same quality and make may be in- 

 stalled the same daj' in a stone crushing plant, for example. 

 Two men will have charge of the operation of the belts. 

 One of the belts may be worn out in a few day.s, while the 

 other ma3' last a year. This difference may be due to any 

 one of a dozen causes, or there may be a number of contrib- 

 utory elements ; but the chances are that the chief fault is 

 most likely in the operator in charge of the belt that gave 

 out first. 



* * * 



In discussing this point with an India Rubber Woki.Ii 

 representntive. a large user of conveyor belts said : " Until 

 we get e.xact uniformity' of conditions, and until all men are 

 exactly .dike, there can be no such a thing as uniformity in 

 the life of conveyor belts. We use manj' belts from 24 to ^o 

 inches wide for conveying raw ores. On general principles 

 we have found the rubber belt the best for our purposes, 

 though we have had excellent results from others. After the 

 ore is crushed we use a smaller belt, and find that for this 

 purpose it is not necessary to use the highest grade rublier 

 belt ; in fact we are getting satisfactory service from canvas. 



■' As a rule, we have been unable to buy belting covered 

 by either a carriage or time guarantee, though we have done 

 so in some instances. Competition is brisk and manufac- 

 turers are willing to make greater concessions than formerly. 

 Just what we shall do if prices go much higher we do not know. 

 It will be time enough to think of that when we have to. 



Ill the first place no one knows to-day which is the best 

 belt. Each manufacturer claims that honor for his product, 

 but his opinion is likely to be biased. We hope to be able 

 to settle this question, to our own satisfaction, at least. We 

 have had a belt made up of sections of the leading brands of 

 conveyor belts, and are running it on our most trying work. 

 Our experts are watching this experiment closelj' and noting 

 the condition of the various sections every daj'. In the end 

 we shall be able to tell what belt is best suited to our work, 

 for it will enable us to make a comparison of belts o])erated 

 under exactly the same conditions." 



* * -K- 



Onk of the severest tests that can be put upon a conveyor 

 belt is that of carrying crushed stone. A representative of 

 one of the biggest concerns in the business said his comi)any 

 used many belts of several makes and varying in width from 

 S to 30 inches. 



"We have had a hint that prices of rubber belts would 

 soon go up, " said he, " but we do not think the advance will 

 be sufficient to be prohibitive. We are using a cotton duck 

 belt that is doing fair work, but we do not believe it will 

 take the place of rubber. The objection to this type is that 

 it is susceptible to expansion and contraction. When a 

 canvas belt gets damp it contracts and 3'ou have to ' set ' in 

 a piece. As it dries out it expands and becomes loose and 

 you have to take the piece out again. 



" There is no way to get at the probable life of a bell any 

 more than there is to get at the probable life of a human be- 

 ing. We have got a few guarantees of conve3'or belts, but 

 they were governed entirely by conditions applying to each 

 belt. A time guarantee depends wholly upon where the belt 

 is to be used and the conditions governing its use. We buy 

 a 36 inch rubber belt 194 feet long, expecting it to carrj' 

 250,000 cubic yards of crushed stone. If it does that we are 

 satisfied; and about two-thirds of our belts do that. Under 

 the most favorable conditions we are getting 350,000 cubic 

 yards from a 30 inch belt 500 feet long. This belt, like mo.st 

 of the others we use, is run flat. We run between 5000 and 

 10,000 feet of belting and about 75 per cent, of it has to be 

 renewed each year. 



" While we prefer rubber conveyor belts for most of our 

 work, there dovibtless are .some places where we could use a 

 substitute advantageouslj- if we were forced to it by high 

 prices, though up to date I have not seen any but rubber 

 belts that would come up to our requirements. There is a 

 belt made of canvas filled with a compound that has the ap- 

 pearance of rubber, that does good work. Its makers claim 

 the filler is not rubber, but it looks and feels like rubber. 

 This belt is not regarded as a competitor of the rubber arti- 

 cle ; it costs less than rubber, but is more expensive than 

 canvas. " 



* » * 



"There is a marked upward tendency in the prices of 

 crude rubber and cotton duck such as are used in making 

 belting." a leading manufacturer said, "and that means 

 that belting must go up. A special compound of rubber 

 and a special weave of duck are required for this purpose. 

 We have made no substantial advance as j-et, but we maj' 



