39 (#75) ############################################## CARDING AND CONDENSING The production of a carding set is dependent upon : (a) the depth of material of any given type which the cylinders will readily control, truly card, and pass forward ; (6) the number of threads taken off the machine and the skeins condensed to, and (c) the speeds at which the several controlling cylinders may be run. Taking (6) first, it is obvious that if 60 threads of, say, 8 skeins are taken off a set of machines (running at the highest economic speed) the maximum weight of condensed sliver delivered is absolutely fixed; and further, that if 16 skeins be the count taken off, for the same number of threads, the weight delivered will be half this, and that if 4 skeins be the count taken off the weight delivered will be double this weight. But the question may be asked, if 40 lbs. per hour of 8 skeins shows satisfactory and economic carding, will not 20 lbs. per hour of 16 skeins be uneconomical, and 80 lbs. per hour of 4 skeins unworkable? This latter question brings up (a) the problem of the depth of material of any given type which can be satisfactorily worked. This problem is treated fully when dealing with double-film cards such as Josephy's ; at this junc- ture it is only necessary to realize that this is a funda- mental problem. It has just been suggested that "speed of delivery' will also affect output. To exaggerate: if the condensed sliver rollers, running at 15 revolutions per minute, give 40 lbs. of 8 skein yarn per hour, the same rollers running at 30 revolutions per minute will give 80 lbs. per hour; or run at 73 revolutions per minute will give 20 lbs. per hour, provided the same weight of film is supplied to them. What then really fixes the speed of these rollers > 39
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