. Rubber hand stamps and the manipulation of rubber; a practical treatise on the manufacture of India rubber hand stamps, small articles of India rubber, the hektograph, special inks, cements, and allied subjects . ld. The purer gum floats; suchpieces as have stones, dirt, iron, etc. in them, per-haps placed there purposely from fraudulent motives,sink and can be jDicked out for separate treatment. The lumps are next cut up. A revolving circularknife driven by power is often used, and sometimesan ordinary knife is adopted. At this part of theoperation there is frequently need for sorting, as t
. Rubber hand stamps and the manipulation of rubber; a practical treatise on the manufacture of India rubber hand stamps, small articles of India rubber, the hektograph, special inks, cements, and allied subjects . ld. The purer gum floats; suchpieces as have stones, dirt, iron, etc. in them, per-haps placed there purposely from fraudulent motives,sink and can be jDicked out for separate treatment. The lumps are next cut up. A revolving circularknife driven by power is often used, and sometimesan ordinary knife is adopted. At this part of theoperation there is frequently need for sorting, as thegrades received may have inferior joieces mixed withthe good. The cutting is mainly to secure goodgrading, and to remove concealed impurities. Thegum then goes to the washing rollers, called thewasher and sheeter. (See cut, p. 37.) ANH THE MANIPULATION OF BUB BE R. 87 These are heavy corrugated rolls made very short,9-18 inches in length, to prevent springing. Theyare grooved or corrugated and have a screw adjust-ment for regulating their distance apart. Theyare geared together so as to work in correspondingdirections, like a clothes wringer or a rolling millof any kind. The pieces of gum are fed into the. Washkr and Sheeteb. rolls and are drawn between and through friction tends to heat the gum. To preventthis and also to effect the washing, a supply ofwater, either hot or cold, is kept playing upon themass. This dissolves out all soluble matter andwashes away mechanically the chips, dirt, may be present. The whole operation is oneof main force. The caoutchouc is torn and dis-tended and delivered as a rough perforated is passed repeatedly through the machine, therollers being gradually brought closer together, orelse different sets of rolls are used, set to different 38 RUBBER HAND STAMP MAKING degrees of fineness. The wash water passes througha screen which catches any small detached frag-ments of gum. Other types of machines have been introduced
Size: 1932px × 1294px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1800, bookdecade1890, bookidrubberhandstamps01sloa
