Ceramic Industry

SPECIAL SECTION/BRICK & CLAY RECORD: Product Profile: Molded Brick-Making Machines

February 1, 2008
Kercher Industries, Inc. recently undertook a major redesign of its Lancaster AutoBrik Machine line.

The Lancaster AutoBrik Model 24HC at Watsontown Brick, with safety fencing.


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.  

Control stand (left), mold injector (center) and hydraulic pack (right).

Improved Design

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.

Empty wooden molds.

Flexibility

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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