A Collection of Papers Presented at the 97th Annual Meeting and the 1995 Fall Meetings of the Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 17, Issue 1

216 Pages·1996·24.73 MB·English

Ceramic
Engineering
& Science
Proceedings
Issue 1, 1996
A Collection of Papers Presented af the
97th Annual Meeting
and the
1995 Fall Meetings
of the
Materials & Equipment
and
Whitewares Divisions
April 30-May 3, 1995
Cincinnati, OH
and
September 13-1 6,1995
Virginia Beach, VA
Russell Wood
Proceedings Committee
Published by
The American Ceramic Society
PO. Box 61 36
Westerville, OH 43086-613 6
Copyright 0 1996
The American Ceramic Society
ISSN 01 96-62 19
W. Paul Holbrook, Executive Director
John B. Wachtman, Editor
Mark Mecklenborg, Director of Publications
Lori A. Kozey, Product Manager
Sarah Godby, Production Assistant
Committee on Publications: David J. Green, chaic Marina R. Pascucci; Man F. Yan;
Richard Haber; James W. McCauley, ex officio; Prabhat Gupta, ex officio; Richard M.
Spriggs, ex officio;T imothy M. Robinson, ex officio;J ohn B. Wachtman Jr., ex officio; W.
Paul Holbrook, ex officio.
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CESPDK Vol. 17, No. 1, 1996
The American Ceramic Society assumes no responsibility for the statements and opinions
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Each issue of Ceramic Engineering and Science Proceedings includes a collection of
technical articles in a general area of interest. These articles are of practical value for the
ceramic industries and the general public. The issues are based on the proceedings of a
conference. Both American Ceramic Society and non-Society conferences provide these
technical articles. Each issue is organized by an editor who selects and edits material from
the conference proceedings. The opinions expressed are entirely those of the presentors.
There is no other review prior to publication.
Foreword
The authors of the papers appearing in this issue of Ceramic Engineering and
Science Proceedings have spent a great deal of time and effort to prepare their
papers for publication, and they have our thanks and appreciation for their efforts.
By appearing in print in one of the American Ceramic Society publications, a paper
is widely distributed and available for reference.
The papers included in this volume were given at the 97th Annual Meeting and
Exposition of the American Ceramic Society in Cincinnati April 30 to May 3,
1995, and at the fall meetings of the Materials & Equipment and Whitewares
Divisions in Virginia Beach, Virginia, September 13-1 6, 1995.
Lori Kozey and Godby of the American Ceramic Society were, as usual, a
Sarah
great help in getting the papers ready for publication.
Russell K. Wood
American Standard Inc.
...
111
Table of Contents
Materials & Equipment and Whitewares
.........
Storage Handling of Ceramic Products by Means of AGVs 1
Hermod Allertsen
................................
Kaolins in Southwest England .3
I.G. Attwood
Technological and Product Requirements for Fast Firing
.......................................
Glass-Ceramic Glazes 11
Luisa Barbieri, Cristina Leonelli, and Tiziano Manfredini
Effects of Polyacrylate and Sodium Silicate Dispersant on
................................
Plaster Mold Characteristics. .23
L. Behal and D. Schelker
.............
Oxidation-Reduction Reactions in Fast-Fire Glazes. .30
Robert P. Blonski
A Preliminary Investigation of Sanitaryware Slip and
................
Influencing Factors for a Pressure Cast System. .40
A.K. Bougher, M.D. Etheridge, and C.A. Lombard0
...........................
Cerdec Bulk Bag Doser Evaluation .47
Kenneth R. Brown
..
Floor and Wall Tile Production Through a Multipurpose Body.. .50
August0 Brusa and Andrea Bresciani
Examination of Fast-Fire Frits and Glazes Using a Hot Stage
........................
Microscope at Different Heating Rates .60
Bruno Burzacchini, Mariano Paganelli, and Heinrich G. Christ
...............................
Advances in Isostatic Pressing .67
G. Davies and E. Blanchard
Hectorite as a Critical Element in Manufacturing High-Grade
..........................
Ceramic Slips, Bodies, and Glazes..
.70
Don Dell
Predictive Process Control: Varying Raw Materials Properties
.......................
Can Produce Constant Body Properties
.72
Dennis R. Dinger and James E. Funk
......................
Analyzing the Color of Reddish Glazes..
.77
Douglas R. Eppler and Richard A. Eppler
Al,O,-Strengthened Feldspathic Porcelain Bodies: Effects of the
.........................
Amount and Particle Size of Alumina .88
Ryusuke Harada, Noriyuki Sugiyama, and Hideki Ishida
...............................
Injection Molding of Porcelain
.99
Uwe Haupt
.................................
Colors for Ceramic Bodies
.lo2
K. Hudson, H. Winbow, and J. Cowley
............
Polyacrylate Developments in Sanitaryware Slurries.
111
Bill Leach, Hal Wheeler, and Trent Busch
.......
Pressure Casting Rate Analysis Using a Baroid Filter Press
117
Bill Leach, Hal Wheeler, and Brad Lynne
International Standards for Lead and Cadmium Release from
................................
Ceramic Foodware Surfaces
.129
Richard L. Lehman
......
Variables Encountered in Dry Pressing Technical Ceramics.
137
Wesley A. Lewis Jr.
In Situ Liquid Pressure Measurements Using a Hypodermic
......................
Needle: Constant Rate Pressure Casting.
144
Ching-Yao Lin and B.J. Kellett
............
The Effect of Ball Clays on Tile Body Formulations
.156
Christopher A. Lombardo
.......................
Optimizing Throughput in Tile Plants.
.163
Christopher A. Lombardo
vi
Coloring Effects of Synthetic Inorganic Cobalt Pigments in
..............................
Fast-Fired Porcelainized Tiles. .167
G. Monari and T. Manfredini
.........
The Chemical Durability of a Boroaluminosilicate Glass 173
Dechun Fu and E.J. Pawlicki
Wollastonite, Pyrophyllite, and Talc for Rapid-Fire Wall Tile
...................................................
Bodies 180
Konrad C. Rieger
.................................
Designing in Ceramic Tile. .183
Pierangelo Righi
Recent Advances in Understanding Gelation in Sanitaryware
.....................................................
Slips 187
D.H. Schelker, F.A. Planchart, and R.J. Thomas
......................................
Evolution in Presses. ,194
Alfred0 Tordi and R. Caruso
Using a Simple Feedback Loop to Accurately Count and Track
..........................................
Work in Process .198
Jeffrey Wagar
.......
Effect of Drying Air Pressure on the Slip Casting Process. .200
A.J. Yarosh and R.A. Haber
.......................................
ColorTrends1995-96 210
Eric Young
vii
Ceramic Engineering Science Proceedings
C?
Editor John B. Wachtman
Copyright@1 996 The American Ceramic Society
Ceram. Eng. Sci. Proc., 17 [l] 1-2 (1996)
Storage Handling of Ceramic Products by Means
of AGVs
HERMODAL LERTSEN
Gruppo Barbieri & Tarozzi SRL, Formigine, Italy
Gruppo Barbieri & Tarozzi began studying the AGV (automatic guided vehicle) system in
1985. This new system, studied to replace traditional handling, is equipped with tracks and
transfer cars. It has obtained considerable success.
This new system, which allows handling boxes or tile containers from storage to the pro-
duction cycle, owes its success principally to the simplicity of installation, economy, plant
flexibility, safety, and rationalization of the space occupied by the equipment.
Installation is simple because it does not require foundation work for tracks and transfer
cars-it uses a flat floor that makes easy any operation during and after the installation.
The costs, globally analyzed (machines, brickwork and civil engineering work, space
occupied, energy costs, and various costs), are lower or sensibly low with respect to tradi-
tional systems.
Plant flexibility means being able to manage the storage in relation to the production in
the most convenient and opportune way according to the requirements (production changes
in real time; use of the same areas for storage of green material, fired material, or empty
boxes; simple extensions or modifications of the plant; more accessibility to the machines;
etc.).
Improved safety is the result of the various devices with which the AGV system is
equipped and the flat floor that allows the operators to move in the plant with fewer hazards.
Since the system does not need tracks and transfer cars, space can be optimized.
The AGV moves autonomously, following pre-established routes because of a battery. The
management of the AGV movements is entrusted to a personal computer, which communi-
cates orders to individual cars by radio.
The functions of the system are management of machine calls with priorities and com-
bined calls, assignment of every call to the nearest vehicle to carry out the service, and con-
trol of the vehicle traffic inside the plant.
The integrated management functions in the system are graphic synoptic scheme of the
plant; product coding; creation of a production plan for each machine the plant, which
allows a completely automatic and computerized production change; management of the
information about the products contained in every box in storage; total content of the storage
area by product; and production data by machine.
The diagnostic functions are video checking of all system YOs, checking the operations of
every vehicle, checking the alarms of every vehicle, checking the radio dialogue of every
vehicle, and registration of all operations and alarms in order to collect statistics.
This leads to an automatically managed plant as far as the production is concerned, and
maintenance control improves.
Laser-navigated AGV systems enable quick adjustments. One important long-term eco-
nomic aspect is the simplicity of making changes and expanding the system. Most industries
often need to modify their material flows but are reluctant to do this because of high invest-
ment costs. The total economy of a production process is often improved if the material
flows easily can be adjusted to meet dynamism and customer requirements.
If production process involves a thick and complex route network, optimization of the
number of vehicles, the possibility of changing the routes and spaces occupied, expansion of
1
andor changing the plant in limited time, then laser-navigated vehicles might be considered.
Until today, the problems of handling, storing, and transporting pallets of finished prod-
ucts always have been considered individually and solved with separate, incompatible solu-
tions.
The AGV system enables driving and management, with a single control unit, of the vari-
ous vehicles used to transport roller boxes (from glazing to storage, from storage to firing,
from firing to storage, and from storage to sorting), pallets of fired product (from firing to
storage and from storage to sorting), and pallets of finished product (from sorting to the fin-
ished product store). This enables the production to be controlled from a central point.
2
Ceramic Engineering Science Proceedings
C?
Editor John B. Wachtman
Copyright@1 996 The American Ceramic Society
Ceram. Eng. Sci. Proc., 17 [l] 3-10 (1996)
Kaolins in Southwest England
I.G. ATTWOOD
ECC International Ltd., Cornwall, United Kingdom
Introduction
Recent statistics suggest that total world production of kaolin is around 26 million tonnes
per year, of which 9 million tonnes are produced in the United States and 3 million tonnes
are produced in the United Kingdom. The ceramics industry consumes about 0.5 million
tonnes, both in the United States and the United Kingdom. Kaolin is produced in southwest
England in Devon and Cornwall counties and 70% of kaolin for the ceramic industry is pro-
duced by ECC International. The southwest kaolins are classified as primary residual and
the deposits have been formed as a result of hydrothermal alteration of the granites. Figure 1
shows the principal intrusions of granite in the region, although some kaolin is found in all
of these intrusions, only the twin intrusions near St. Austell and the southwest sector of the
Dartmoor massif have been extensively kaolinized. The process of hydrothermal alteration
occurred some 275 million years ago, and kaolinization was the result of the successive
effects of high-pressure steam and hot acidic vapors and solutions on the feldspars contained
in the granite. Kaolinization extends to depths in excess of 300 m, the degree of kaoliniza-
tion; therefore, the mineralogical composition of the matrix varies widely. The matrix is an
intimate mixture of kaolin, quartz, mica, and traces of unaltered feldspar. A typical matrix
composition or extraction breakdown is 15% rocks, 70% quartz sand, and 15% kaolin. Some
coarse mica will be present in the sand fraction and some fine mica will be present in the
kaolin.
Figure 1. The principal granite areas of Cornwall and Devon.
3
Production Process
The ECC International production process divides conveniently into three main parts: pit
operations, refining operations, and blending. All of these are subject to comprehensive
quality control procedures, which are registered to IS0 9000. Quality control will be
reviewed as an overlay of the whole process.
Pit Operations
Kaolin is extracted using open-cast mining, and operations commence with stripping over-
burden. This overburden consists of soil, peat, and a hard rock capping. The exposed
kaolin-bearing matrix is loosened by explosive charges, and the face is then washed using a
high-pressure water jet. During the production process, the majority of the other minerals
present are removed by particle size separation techniques: the particle size distribution of
the minerals present in the crude kaolin is shown in Fig. 2. Refining techniques will remove
all the quartz and a large proportion of the mica. The particle size distribution of the latter,
however, results in the presence of a significant level of mica in the finished product. The
typical mineralogy of a kaolin product is 84% kaolinite, 14% mica, 1% feldspar, and 1%
quartz.
Figures 3 and 4 show a schematic flow sheet of the production process. The remote con-
trolled water jet delivers approximately 2000 gal/min at a pressure of 280 psi. The kaolin
wash descends to the bottom of the pit where it is pumped into either spiral or bucket-type
sand classifiers. The coarse quartz is removed at this stage and is transferred to the sand tip.
The kaolin wash is then pumped to the pit hydrocyclones, which remove all particles greater
than 60 pm. The residue is mainly coarse mica and some sand, which is pumped to the mica
dam.
On leaving the pit hydrocyclones, the kaolin wash is pumped to the surface for dewatering
prior to the refining stage. The pit wash is around 5 tonnes of solids content and dewaters in
140-ft diameter tanks to a solids content of 25%. The kaolin is in the natural flocculated
state and settles readily. The tanks have a conical base and are fitted with rakes that move
very slowly and concentrate the dewatered kaolin to the center of the cone, where it is
removed. Each tank holds the equivalent of 1000 tonnes of dried product.
The finished kaolin product will be made up of a number of kaolin components from dif-
ferent pits, each of which will pass through a refining process. The four major pits in the
Cornwall area produce more than 20 different kaolin components: the blending process is
then used to combine specified components together to produce a final kaolin product.
100
80
%
60
z
K
$ 40
20
0
100 10 1
Figure 2. Minerals distribution: crude clay.
4