MOLDING OF CONICAL CERAMIC ARTICLES
FROM AQUEOUS SLURRY
F. Ya. Borodai,
V. V. Platonov,
and M. A. Volkov
Translated from Novye Ogneupory, No. 12, pp. 27 – 32, December, 2010.
Original article submitted September 16, 2010.
Results of design and construction developments focused on the problem of centering of a core in the cavity of
a gypsum mold, the production of ceramic blanks with thickness variability and specified shape, and ways of
increasing the uniformity of articles in molding of large sheathing for antenna radomes by means of aqueous
slurry casting are presented.
Keywords: ceramic sheathing, slurry casting, plant for molding of sheathing, centering of the core, kinetics of
edging process, homogeneity of material
Aqueous slurry casting in a gypsum mold is the simplest
method of molding of ceramic articles. A method involving
pouring of the slurry cast with the use of an active gypsum
mold and passive core is the basic method in the production
of large articles, in particular, sheathing for the antenna ra-
domes of aircraft made of quartz ceramic and Sital ceramic
. The technological parameters of aqueous suspensions of
these materials and the drying and sintering regimes have
now been selected and optimized, thus assuring integrity of
the articles following molding and roasting as well as guar-
anteeing that the required properties of materials will be ob-
However, in the course of molding of large and lengthy
tapered sheathing there arise a number of problems. These
may be overcome through the development of new designs
of molding assemblies, including the following steps:
– centering of the core in the cavity of the gypsum mold;
– creation of sheathing with thickness variability, above
all, of sheathing that is thicker at the base;
– assuring a high degree of uniformity in the properties
of large sheathing.
A general view of a plant for molding this type of sheath
ing is shown in Fig. 1. The plant comprises a tilter 1,en
abling mounting and rotation of the molding assembly, a
gypsum form (matrix) 2 in a perforated casing with upper
and lower flanges, passive core 3 with bearing flange, pour
ing gate 4 which serves to center the core and assure uniform
maintenance of the level of slurry on all faces of the molded
billet, feeder tanks 5, a feed pipe 6 for filling the mold and
feeder tanks with slurry, an extractor 7, and stage 8 for re
ceiving and transporting the article. There is no model here
that would function like a core and would be inserted into the
mold as the gypsum was being poured.
Refractories and Industrial Ceramics Vol. 51, No. 6, March, 2011
1083-4877/11/5106-0447 © 2011 Springer Science+Business Media, Inc.
FGUP ONPP Tekhnologiya, Obninsk. Kaluga Region, Russia.
Fig. 1. General view of plant for molding ceramic cores by means
of aqueous slurry casting.