IMPROVING MOLD SETS FOR LARGE-SIZED COMPONENTS
PREPARED FROM AQUEOUS SLIPS.
PART 1. WORKING MATERIAL FOR THE MOLD SET
E. I. Suzdal’tsev, D. V. Kharitonov, A. V. Dmitriev, and T. P. Kamenskaya
Translated from Novye Ogneupory, No. 3, pp. 47 – 52, March, 2006.
Original article submitted December 12, 2005.
Working materials for mold sets used in slip casting technology are reviewed. Benefits and shortcomings of
the materials are discussed and routes towards improving their performance are suggested.
For all varieties of molding techniques currently em-
ployed in the ceramics industry, slip casting into porous
molds is one of the most popular. Slip-casting technologies
for various materials share common features that can briefly
be summarized as the following steps : (i) fabrication of
molds and their preparation for casting operations; (ii) prepa-
ration of the dispersion medium and disperse phase;
(iii) preparation of the slip; (iv) molding to produce green
preforms; (v) extraction of preforms from molds; (vi) drying
of molds and preforms. It can be said that individual steps of
a technological line for the casting of preforms from an aque
ous slip in porous molds are not always easily matched.
Within a systems approach, the updating of mold sets for
aqueous slip casting involves technical, functional, and eco
nomic aspects. Each of these aspects bears upon the interac
tions and relations between elements of the process. A sche
matic of the slip casting process is given in Fig. 1; it de
scribes a general flowchart for manufacture of large-sized
complex-shaped components [2 – 5].
In the target tree diagram in Fig. 1, the mold set takes a
central place as if to emphasize its significance in production
process chart. Still, this implies by no means detracting from
the importance of other properties of the slip casting techno
logy. These properties (parametrized as precursor materials
for fabrication of molds and preforms, molding techniques,
etc.) are shown arranged along the perimeter of the target
In developing a particular mold set, any suitable material
can be used which allows the easy fabrication of a mold
meeting a range of important requirements such as an exact
replication of the model configuration, the ability to accumu-
late liquid phase from the slip, chemical inertness towards
the slip, and durability. The best suited material for that pur-
pose was plaster; currently, it is widely used in the ceramics
industry for molding preforms from aqueous slips.
In this work, concerned mainly with improving the per-
formance of mold sets, a major goal was to prepare large-
sized complex-shaped components in the form of a solid of
revolution using aqueous slips based on quartz and lithium
aluminosilicate glasses. The schematic diagram of a mold set
Refractories and Industrial Ceramics Vol. 47, No. 2, 2006
1083-4877/06/4702-0116 © 2006 Springer Science+Business Media, Inc.
Technologiya Research and Production Enterprise, Obninsk,
Kaluga Region, Russia.
Fig. 1. A target tree for improving mold sets: T (target)) manufac
ture of a high-quality component at a minimum of production, mate
rial, labor, and time costs; P) problem to be solved; LA) level
achieved in the preform molding; AMS and SMS) analog mold sets
and problem-solving mold sets, respectively; MF and PF) prototype
molding fabricability and problem fabricability; MR and PR) proto
type mold set resource and problem mold set resource; MC and PC)
prototype mold set cost and problem cost.