A 150-year product guarantee makes a confident statement about a company’s engineering, production and quality capabilities. For Palmetto Brick Co., it represents a longstanding commitment to continuous process improvement and strong customer relationships.

Each year, the company produces more than 100 million brick from its base of operations in Cheraw, S.C. To maintain its technological edge and move its quality assurance program into a real-time computing environment, Palmetto Brick recently implemented Synergy 2000^TM statistical process control (SPC) software across its manufacturing network.

Developed by Zontec Inc., the Synergy 2000 software manages quality data so that the Palmetto brand maintains its superior reputation and meets customers’ expectations for durability and aesthetics. According to Todd Butler, process engineer at Palmetto, the SPC software vendor was best aligned with Palmetto’s internal quality strategy. Palmetto preferred Zontec’s off-the-shelf Windows^®-based application (with related rapid implementation and short financial payback) over full-blown enterprise resource planning (ERP) or manufacturing execution systems (MES), which do not offer clear-cut timelines or value.

Harnessing the Process

“To achieve process consistency, we must monitor our raw materials and quality characteristics very closely to reduce or eliminate any variability that can be measured in the process,” says Butler. Brick-making at Palmetto also involves strict adherence to international building and construction standards set forth by ASTM International, as well as independent annual product testing conducted at Clemson University’s National Brick Research Center. “The product tests are an insurance policy to confirm that the research data matches what we recorded on-site in our lab,” adds Butler.

By nature, the composition of clay presents a wide range of performance tendencies that must be monitored, controlled and adjusted to achieve engineering compliance. “Different raw materials cause bricks to fire differently,” notes Butler.

Palmetto mines its clay from more than 1200 acres of company-owned land in the region. “We take advantage of a variety of raw materials in our geographic area to deliver a line of colors that are a distinct competitive edge,” Butler points out. Having access to an abundant source of kaolin, alluvial clay and shale allows Palmetto to create a palette of hues that run the gamut from red, brown, tan and buff to gray and white, all with a variety of sizes.

From the mining of the clay to the slow ride through the kiln, the brick manufacturing operation lends itself to numerous opportunities for statistical process control to introduce refinements very early in the production process. SPC offers a proactive approach based on predicting and preventing adverse events.

“It’s critical that we find out about any problems as quickly as possible and before the molding stage,” Butler says. “Modifications to the process or raw materials can occur anywhere before the molding phase. Otherwise, it’s too late to do anything about it once the product is fired.”

During the work-in-process time (5½ to 6 days), Palmetto’s production team is engaged in such quality control activities as:

• raw material testing
• blending confirmation
• checking for size on extruded but unfired green brick
• performing void tests
• measuring moisture pre- and post-firing
• inspecting for appearance, chippage and other defects
• comparing color runs for consistency
• checking for shrinkage on fired bricks
• deriving a saturation coefficient based on 5/24-hour absorption tests

Timely Information

Figure 1. Green, yellow and red status flags within the SPC software communicate which processes need attention. Users can zoom in on individual quality characteristics to view a chart or the data spreadsheet by clicking a status flag.

The Synergy 2000 software consists of three distinct components (Operator, Engineer and Manager Levels) that complement the functional roles and responsibilities of each type of employee. Operator-Level users enter sample data for the various quality characteristics being monitored. However, the software provides capabilities beyond the capture of raw data.

As data flows into the system, real-time feedback of the process status is displayed using traffic-signal-inspired indicator flags: green for problem-free conditions; yellow for trends that may lead to potential defects; and red for characteristics that are statistically out of control and/or fall outside engineering specifications, thus demanding an immediate corrective action (see Figure 1).

Figure 2. The software generates real-time control charts to indicate when random samples of product are outside SPC limits or to show trends that may lead to out-of-control conditions.

In addition, the software can be customized to automatically display control charts, histograms, process capability indices, and dozens of other SPC charts alongside the process alarms to show patterns in the data and shifts in the process (see Figure 2).

The Engineer Level gives Palmetto the tools needed to set up control plans, configure the system for all users, construct audit trails for traceability purposes, and analyze and report on the data. One specific analytical feature, the Pareto analysis function, is a problem-solving tool used for identifying, ranking and prioritizing production issues to help quantify losses.

The Manager Level enables Palmetto to monitor all of its production activity simultaneously via a multi-plant dashboard view. A series of executive-oriented summary and reject reports are included within the Manager Level of the software.

Going Paperless

Palmetto uses SPC software to monitor raw material properties and shrinkage so the proper green size is extruded to meet final product dimensions.

Prior to implementing Synergy 2000, Palmetto used a combination of paper-based records and Excel^® spreadsheets to provide an overall picture of its quality. Now the data is all on-line and immediately accessible for networked decision support.

To prepare for a successful software launch, Palmetto opted for a comprehensive one-day training session led by a Zontec technical staff member at the brick manufacturer’s facility. Palmetto’s emphasis on technology and real-time SPC is a natural follow-on to its recent $28 million investment in a new commercial plant that incorporates state-of-the-art automation equipment, robotics and stringent emission control systems.

For more information regarding SPC options in brick manufacturing, contact Zontec Inc. at 1389 Kemper Meadow Dr., Cincinnati, OH 45240; (513) 648-9695; fax (513) 648-0805; e-mail spcinfo@zontec-spc.com; or visit the website at www.zontec-spc.com. Palmetto Brick’s website is located at www.palmettobrick.com.