Society of Glass Technology · [Sheffield] · leaf 547
25, in whichit is blown to articles of thedesired shape, 26. The hotcore keeps the quartz hot whilstit is being transferred and whilstit is in the mould. The blowing is accomplished by a hot gas orsteam under pressure, so as to avoid any appreciable chilling. S. E. 209. Making- Sparking-plug… … Fig. 103. GLASS : MANUFACTURE AND PROPERTIES. 117 sparking-plug insulators from silica glass. Two tubes or rods offused silica are heated by rotating them in close proximity toelectric arcs. When the rods arc soft, a core, preferably of woodand therefore combustible, is introduced between the rods,…
Glass
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