The manufacture of rubber goods : a practical handbook for the use of manufacturers, chemists, and others . le,elastic varnish is difficultto prepare. It consistsin general of linseed oil,litharge, and sulphur, witha little oil of turpentine,and is painted over thewhole of the shoe, includ-ing the sole, by meansof a large martens-hairbrush, the solution beingmade sufficiently thin notto froth. If frothing takesplace the solution mustbe diluted. Varnishescontaining a ready-madeblack ingredient, such asasphaltum, are not, as arule, so valuable, and aregenerally used only forafte^r-varnishing. In
The manufacture of rubber goods : a practical handbook for the use of manufacturers, chemists, and others . le,elastic varnish is difficultto prepare. It consistsin general of linseed oil,litharge, and sulphur, witha little oil of turpentine,and is painted over thewhole of the shoe, includ-ing the sole, by meansof a large martens-hairbrush, the solution beingmade sufficiently thin notto froth. If frothing takesplace the solution mustbe diluted. Varnishescontaining a ready-madeblack ingredient, such asasphaltum, are not, as arule, so valuable, and aregenerally used only forafte^r-varnishing. InAmerica shoes are var-nished in the followingway. The shoes arearranged on their lasts oniron racks, and are takento the varnishing - room,where they are removedfrom the racks; the topedge is rapidly run overwith the brush, and thew^hole shoe is then dijDjDedin the thin solution ofvarnish, and immediatelyafterwards is put back onthe rack. It is essentialthat the lacquer should notflake off, and the pliabilityof the upper is a valuable factor in this connection, since the varnishes make intimate contact. MANUFACTURE OF SOFT-RUBBER ARTICLES. 187 with it. The varnish has to go through the vulcanising process,and is therefore subjected to a very high temperature; all volatileconstituents (with the exception of the very volatile benzine withwhich it was diluted) must therefore be completely driven off byheat before it is used, so that no vapours can possibly be given offduring vulcanisation, and form blisters. In spite of this precautiona varnish may go wrong on heating so that to make absolutelysure that it is all right it is tested before actual use, by coating a smallpiece of the shoe rubber with it, and subjecting this to .vulcanisation,(f) Vulcanisation of Galoshes.—This is carried out exclusively t--Sr?r- 1 rJl^ ^S^—, M ,g^ 4?, il .Mj^^. ~~j2 i ^\^\l • • \ - —- 1 • • iL^^ti: &^ ^ T® m. or r^ -^HFl>>.*VWLW^J^ll « Fig. 87. in hot-air chambers, since the sho
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Keywords: ., bookcentury1900, bookdecade1910, bookidmanufactureo, bookyear1919
