SPECIAL SECTION/BRICK & CLAY RECORD: Tumbled Brick Goes High-Tech
Over the past few years, the development of new products in the U.S. brick industry has primarily been driven by aesthetics. The proliferation of unique colors and textures by brick manufacturers is virtually unmatched by other cladding materials.
One aspect of product development that continues to grow is the demand for the used or antique look. For years, a number of manufacturers have distressed previously fired products by blending and tumbling them in rotating steel cylinders. In many cases, off-quality products are used in this process, which helps relieve inventory problems and reduce discards to the grog pile. Typically, this process produces distinctive, value-added products but is quite labor-intensive and costly.
In another process, green brick are distressed by pushing the extruded slug through the wire bank and dropping the individual brick onto an inclined steel plate. The green brick roll and slide from the plate onto a conveyor, which further distresses the product as it moves to the hand-setting area. This brick distressing technique is also very labor-intensive and expensive as a result of the high labor requirements associated with hand setting and kiln car loading. Improvements to this green tumbling process, primarily related to labor savings, can be achieved with the incorporation of automation.
How it WorksA new approach makes it is possible to mechanically set and unload the embossed brick without the expense of hand labor. The technology can be integrated into an automatic production line, where the arrises on both ends of the clay slug are textured using a newly developed V-shaped stamping device and subsequently pushed through a multi-wire cutter.
As the clay column exits the extruder and heads down the conveyor toward the slug cutter, the bar can be textured. Engobes and other surface coatings can also be applied at this stage. The column is then cut into the appropriately sized slugs for further processing. An individual slug is stopped on a reference point to enable subsequent alignment with the wire cutter bank. With the brick stamping device installed in-line, the stamping tools are able to distress what will become both ends of each individual brick.
The type and degree of distress or distortion can be modified to suit the brick manufacturer’s requirements. For example, the tools could incorporate a V indentation coupled with other possible distress shapes. Once these V-shaped configurations have been stamped on the slug, the indentations align perfectly with the cutter wires, even if the slug is indexed further down the line to align with the multi-wire cutter. As the slug is pushed through the wire bank, the brick are cut exactly in the center of the stamped indentation as a result of the exact positioning of each slug. The distress marks on each brick simulate the flattened or distorted corners that would occur had the brick been produced in a green tumbled process.
The tools incorporating the V shapes are available in a variety of dimensions and shapes. In some instances, the brick manufacturer may want to have several brick in the slug with no distress, which can provide additional variations in the appearance of the final product.
The size range of the multi-wire cutter is 30-50 modular brick long and, therefore, the repetition of the brick distortion is generally not a problem. If the brick manufacturer desires a wider selection of stamped brick to provide a more random appearance in the wall, this new technique offers the possibility of increasing the number of tools that can be automatically exchanged by rotation with each slug. This tool rotation effectively doubles or triples the repetition to as many as 90-150 brick.
The new stamping machine distresses only the four short arrises on the front and back of the brick. This amount of distress or distortion is acceptable for many manufacturers in developing a product that closely emulates a green tumbled brick. However, the addition of distress to the long brick arrises can also be added, if necessary.
A series of sharp-edge flat rolls that incorporate various bumps or protrusions is mounted prior to the cutter bank, with each roll directly aligned with an individual wire. When the slug is pushed toward the wire cutter, these rolls imprint the edge of each brick with the various distress marks. As the slug push continues, the wires precisely align with each chamfer created by the horizontal distress rolls and the stamping for all four vertical corners.
Multiple BenefitsThe newly developed stamping system allows the stamped brick to be precisely pushed through the multi-wire cutter, faced and stacked, and set directly on kiln cars with a simplified robotic setting machine. This seemingly complicated approach to producing a simulated green tumbled brick has been proven sound, reliable and very cost effective. In addition, with this integrated manufacturing unit, maintenance is reduced to a minimum, product handling is vastly improved, and the efficiency of the system nears 100%.
The brick stamping equipment can result in the virtual elimination of the labor requirements currently associated with the production of simulated tumbled brick. An additional benefit is that the compact, integrated unit can be fitted to existing setters, as well as new equipment.
For more information, contact Ceric, Inc. at 7815 Shaffer Pkwy., Littleton, CO 80127; (303) 277-0404; fax (303) 277-0506; e-mail firstname.lastname@example.org; or visit www.cericus.com.