Vulcanite and celluloid : instructions in their practical working for dental purposes / by S. Eldred Gilbert.

  • Gilbert, S. Eldred.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Vulcanite and celluloid : instructions in their practical working for dental purposes / by S. Eldred Gilbert. Source: Wellcome Collection.

Provider: This material has been provided by the University of Toronto, Harry A Abbott Dentistry Library, through the Medical Heritage Library. The original may be consulted at the Harry A Abbott Dentistry Library, University of Toronto.

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    the mercury-bath; C, thermometer; D, screw-plug; E, lam-nut; F, stem of steam-valve ; G, screw-cap; H, large screw for closing the flask; I, I, I, smaller screws for same purpose; K, K, K, L, nickel-plated caps for screws; 0,0, steam chamber. Working Celluloid with the ]Sew-Mode Heater. To secure the best practical results, celluloid should be molded or pressed into the form desired, at the highest possible temperature which will not burn it. To prove this it is only necessary to mold a plate on a metal cast at the lowest temperature at which it can be done, which is about 212° F., and another on the same cast at the high- est temperature possible, say 310° or 320° F., and lay the two aside for a few days, when it will be found that the one molded at the lower temperature will not fit the cast, while that molded at the higher temperature will fit as well as when first made. The reason is that the low tem- perature fails to overcome the tendency of the plate to re- turn to its original form, while the high temperature ren- ders it so thoroughly plastic that this tendency is entirely eradicated. This is proportionally the case with pieces made at intermediate temperatures; the higher the tem- perature to which the plate is subjected in molding, the more exactly will it hold its new form and the less will be its tendency to warp. Celluloid may be readily and safely manipulated in the ISTew-Mode Heater at 320° F., a temperature many degrees higher than is deemed safe in other machines, and which