Scientific American Supplement, No. 620, November 19,1887 by Various
page 40 of 138 (28%)
page 40 of 138 (28%)
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the filaments are found to adhere to it, having been swept against it
by the scouring action of the water. The cleaning of the cocoons is performed by means of a mechanism also entirely new. In the brushing machinery the floss is loosened and partially detached from the cocoon. The object of the cleaning machine is to thoroughly complete the operation. To this end the cocoons are floated under a plate, and the floss passed up through a slot in the latter. A rapid to and fro horizontal movement is given to the plate, and those cocoons from which the floss has been entirely removed easily give off a few inches of their filament, and allow themselves to be pushed on one side, which is accomplished by the cocoons which still have some floss adhering to them; because these latter, not being free to pay off, are drawn up to the slot in the plate, and by its motion are rapidly washed backward and forward in the water. This washing soon causes all the cocoons to be freed from the last vestiges of floss without breaking the filament, and after about twenty seconds of movement they are all free and clean, ready for reeling. We have now to explain the operation of the machine by which the thread is formed from the prepared cocoon. At the risk of some repetition, however, it seems necessary to call attention to the character of the work itself. In each prepared cocoon are about a thousand yards of filament ready to pay off, but this filament is nearly as fine as a cobweb and is tapering. The object is to form a thread by laying these filaments side by side in sufficient number to obtain the desired size. For the threads of raw silk used in commerce, the sizes vary, so that while some require but an average of three filaments, the coarsest sizes require twenty-five or thirty. It being necessary keep the thread at as near the same size as possible, the work required is, in effect, to add an additional cocoon filament to |
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