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Ât Bell Telephone Laboratories' ceramics department, a great variety of precision-machined, experimental parts have been developed and processed. Parts similar to these play an important role in Bell apparatus—vacuum tub>es, resistors, and others

Ceramics, Tailor Made C E R A M I C S with their many advantages—versatile structural qualities and

unusual electrical, magnetic , and piezoelectric properties—serve the telephone industry, in weather resistant insulators on pole lines, in underground conduits of vitrified clay, in the porcelain enamel finish inside the new telephone booth, and in many other ^vays, To find n e w and better methods and materials for these uses. Bell Telephone Labora­tories is applying scientific knowledge to the ancient art of ceramics.

After lab tests, a ceramic faces larger scale testing in the d e ­velopment shop. First, raw materials are poured into a ball nrnill

A new ceramic material undergoes man tests in its development, as here in a coi stant-temperature, specific gravity bat

After grinding and mixing, the ceramic is filtered, then drii in an oven; finally, the cakes are reground to a fine powd

4218 C H E M I C A L A N D E N G I N E E R I N G N E W S

iORIAL PRESENTATION

etal-bonded d i a m o n d grinding wheels 3 used in gr inding ceramic surfaces r the c lose to lerances necessary in *h frequency electronic equipment

Ground powder can also b e extruded 5mto rods for later fabrication into special parts for v a c u u m tubes. At left, rods are readied for firing; a b o v e . thev are fired in a vertical tubular

In preparing mol ten glass foer use in a n e w glaze, the lat> worker above removes a c r u ­cible conta in ing the glass fronça a gas-fired pot furnace. Α_ΐ right, h e pours it into cold \vate 3· which fractures it into fine paro­t ides . The result ing glass frLt is then ball mil led with wate-τ a n d other materials to form t h ^ glazing material

In one jprocess- a hydraul ic rtt.ni presses the ground p o w d e r into slugs. Later they are fabricated into electrical insulators

V O L U M E 3 1 , N O . 4 1 O C T O B E R 1 2 , 1 9 5 3 4219