SPECIAL SECTION/BRICK & CLAY RECORD: Product Profile: Molded Brick-Making Machines
February 1, 2008
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| The Lancaster AutoBrik Model 24HC at Watsontown Brick,
with safety fencing. |
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Kercher
Industries, Inc. recently undertook a major redesign of its Lancaster AutoBrik Machine line.
This year, the Lancaster AutoBrik Machine
(ABM) will celebrate 150 years of automated molded brick production. The
current machines produce approximately 500 million sand-molded and water-struck
brick annually. Kercher Industries, Inc., manufacturer of the Lancaster
Products line of process equipment, recently undertook a major redesign of its
Lancaster AutoBrik Machine line, introducing the AutoBrik Machine Model 24HC in
2007.
Improved Design
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| Control
stand (left), mold injector (center) and hydraulic pack (right). |
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The Lancaster Model 24HC ABM is designed for
the manufacture of special shapes and low-volume runs of either sand-released
or water-struck standard brick, as well as pavers, flat roofing tile and
refractory brick, in a variety of sizes and shapes. The mold box area is large,
and the brick die plate is simply constructed. Both are easily changed, as is
the mold table elevation. The PLC control allows for special filling of the mud
box and for double-pressing of one mold box for the efficient filling of almost
any size or shape of mold.
The primary goal of the design of these systems is to keep their
maintenance and operation as simple, safe, clean and quiet as is practical,
while providing a system that is tough enough to withstand the rigors of
operating in a brick-producing environment. The major design changes to the new
Model 24HC are in the system’s electronic controls and the hydraulic feedback
to the controls, which allow for more automated control of the AutoBrik system.
All cylinder strokes can be set on-the-fly by the operator through the AB
Panelview, and the adjustment of the press can be varied automatically for
changes in mud consistency. Various other control and mechanical improvements
have also been made in the new machine.
Principle of Operation
In its simplest form, a Lancaster AutoBrik
System consists of the Lancaster ABM with a pugmill/feeder to premix and feed
the clay into the vertical pugmill, which feeds the press box. The
semiautomatic Model 24HC provides for automatic mold injection, mold bumping,
pallet placement, mold and pallet inverter, and a takeoff conveyor, with manual
circulation of the molds.
The entire Lancaster Model 24H AutoBrik Machine System is controlled by an
Allen Bradley PLC, and the PLC-based controls operate all major functions of
the system. The PLC provides for the changing of the system timing to most
efficiently handle the different styles of brick that can be produced on the
Lancaster ABM, and it also helps compensate for mud variances in the press box.
The system features PLC-controlled linear hydraulic action for the press and
the pushout. Individual motor action drives the standard single-shaft pugmill/feeder,
the vertical pugmill and the bumpers. The press can be programmed to double- or
quad-wipe mud into the press box. It can also be programmed to double-press on
one mold, which is especially useful in filling large and deep molds that are
often hard to fill.
If required, the raw material is first introduced into a pre-pugmill that is
attached to the ABM. This pre-pug mixes the material and introduces it to the
pug-feeder on the machine. In a basic ABM, the material is mixed and brought
forward in the integral pug-feeder, which discharges directly into the vertical
pugmill. The vertical pugmill continues to mix and densify the material as it
is brought downward to the large wiper blades behind the press box. When the
press is elevated, material is forced into the press box. The press then
descends and forces the mud out of the press box, through the brick die and
strike-off plate, and into the sanded empty wooden mold.
The mold injector takes the sanded empty mold and injects it into the AutoBrik
24HC, and the empty mold is then pushed under the press box. The empty mold
pushes the filled mold forward as it moves under the press box. As the filled
mold moves forward, the strike-off plate under the press box removes excess mud
from the mold and retains the mud within the press box.
While the filled mold is pushed from under the press box and onto the exposed
mold table, two sets of mechanically driven bumpers impact the sides of the
molds to aid in the release of the mud from the molds. The timing, the number
of bumps and the force of the bumping action can all be adjusted through
changes to the mechanical and electrical drive of the bumpers.
After the molds are bumped, a pallet is dropped onto the top of the
single-piece mold containing the green brick. The mold is then pushed into the
mold inverter, and this mechanism turns the mold with the pallet upside down so
that the mold opening faces downward on the pallet. The mold and pallet then
move down the dual belt mechanism of the take-away conveyor and are staged for
introduction to the demolding position. The mold is then manually removed from
the green brick, which are then moved to the dryer car. Electrical drives are
used on the inverter and the conveyor drive.
The molds are manually placed into the enclosed sander for one pass through the
sand bed. The sanded molds are then manually returned to the mold injector
position. The molds can be periodically washed in an automatic mold washer; the
frequency is determined by the raw material and sand being used.
Flexibility
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| Empty wooden molds. |
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The Lancaster Model 24HC AutoBrik Machine
System was recently installed at Watsontown Brick Co. in Watsontown,
Pa. Watsontown Brick is a 100-year-old
facility located along the Susquehanna River.
Previously, Watsontown Brick exclusively produced extruded brick, but the
company is currently building a new production facility that will be devoted to
molded brick production. A Lancaster AutoBrik Model 46H will be installed in
this new facility.
While the new plant is being constructed, Watsontown ordered a Lancaster
AutoBrik Model 24HC to be temporarily installed alongside one of the current
extruder lines. When the extruder line production is done for the day, the 24H
AutoBrik can be run using the extruder as a prepug mill for molded production.
The Lancaster AutoBrik Model 24HC uses the same style wooden molds and direct
press action as the larger AutoBrik Model 46H. The brick produced by the new
Model 24HC can have the same style and look as the brick currently being
produced on the high-production Lancaster Model 46H AutoBrik Press.
Some of the changes that were made to the
AutoBrik Model 24H were made to give the Model 24HC an operating “feel” more
like the large-production AutoBrik Model 46H. Since Watsontown is new to molded
brick production, operating the AutoBrik 24HC in advance of the large-scale
molded production allows the Watsontown Brick organization to become more
familiar with molded brick operations prior to the startup of the new facility.
For more information, contact Lancaster
Products, Kercher Industries Inc., 920 Mechanic St., Lebanon, PA 17046; (717)
273-2111; fax (717) 273-2967; e-mail info@lancasterprd.com; or visit www.lancasterprd.com.
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