From conception to casting: Conbraco's greenfield expansion.
Handed a blank drawing board, the employees of Conbraco Industries' Matthews, North Carolina brass foundry were given the opportunity to design their company's new foundry and their new work environment. From the coremaking equipment to the shakeout line and from the fluorescent lights to the floor material, these employees were responsible for product flow, production speed and meeting environmental regulations for the new 170,000-sq-ft greenfield plant (70,000-sq-ft foundry) to be built in Pageland, South Carolina.
"We wanted a foundry built by foundrymen," said David Sherman, foundry manager. "Our employees knew our product and what we were trying to accomplish. They were the best resource for ideas and the best design team for the job."
"If we only let outside foundry engineers design the plant, they wouldn't understand how our product and materials flow," said Glenn Mosack, vice president of operations. "Our foundrymen can look at every aspect of our business to design a foundry that is the most cost-effective for us. Our foundrymen know the core machines, molding equipment and the furnaces and how they must interact during production cycles."
The ideas and resultant foundry design incorporates some of the most advanced systems ever used in a green sand brass foundry, including a completely automated green sand system, computerized core tracking and an automated stopper rod pressure pouring line.
The following profile of Conbraco's new green sand brass foundry looks into the decisions behind building this greenfield plant and how it optimized casting production, efficiency, manufacturing space and environmental compliance while reducing the labor force and overhead costs.
History of Expansion
In 1928, two established brass companies in Detroit - American Lubricator and Brass Co. (est. 1901) and Sterling & Skinner Manufacturing Co. (est. 1899) - merged to form Consolidated Brass Co. (Conbraco), a firm devoted to the manufacturing of water gauges, safety and relief valves, gauge cocks, air cocks and other valves for the plumbing, heating and cooling industries. After the company relocated to Charlotte, North Carolina in 1955 to ease the union burden it was experiencing in Detroit, it built its first brass foundry in Matthews, North Carolina in 1957, and then relocated all operations to Matthews in 1960. From 1969 to 1994, the firm continued with non-foundry expansion in Pageland, including opening: its Apollo Ball Valve Div. testing, machining and assembly plant in 1969; the R-P&C Valve Div. testing and assembly plant in 1989; and the Carl L. Mosack Corporate Distribution Center in 1993. In 1994, sensing the valve market's demand for a higher line of products, Conbraco spent $18 million and established a fully automated investment and nobake foundry in Conway, South Carolina, for the production of stainless and carbon steel and high-alloy valve bodies. The success in design and construction of this foundry with its use of robots and computerization set the wheels in motion for a modernization and expansion of its existing green sand plant in Matthews.
The almost 40-year-old Matthews foundry was deemed outdated from a production and environmental standpoint. Conbraco had additional orders for its own line of brass products and it was looking to bring in outside casting customers.
"The equipment, layout and material handling were pushed to the limit," said Mosack. "Although we were producing the quality and quantity our organization required at the time, we did it with an excessive amount of overtime and a lack of space. In addition, the pending OSHA requirements for airborne lead were going to push us into a predicament."
For the Matthews foundry pouring leaded brass alloys, compliance with the OSHA regulation that calls for lead particles in the air at less than 50 parts/microliter would have meant the purchase and installation of additional baghouses and other air-purifying equipment for a plant not designed to use them. The cost would have been in excess of $2 million simply to comply with the regulations.
In terms of production, its 140 employees producing 14 million lb of valve castings were operating in every "nook and cranny." Conbraco looked at the opportunity to expand the existing facility, but there were five problems staring them in the face:
* the available labor market in Matthews was small and shrinking as the city of Charlotte (12 miles away) was growing and employing any available workers;
* only 10 acres around the Matthews plant were available for expansion, so even if it decided to increase manufacturing space it wasn't going to be able to expand the facilities enough to take on the amount of production (more than 15 million lb) it currently required in addition to having space for future expansion and technology upgrades;
* the layout of the plant already was in disarray so even a small capacity expansion would have required a total redesign of the interior flow;
* a hospital and other medical facilities were built in direct view of the foundry, and Conbraco was worried about the odor and noise that emanates from construction, and more importantly, an operating foundry.
After the determination was made that expanding the existing Matthews foundry wasn't feasible, the first option Conbraco considered for its new facility was Mexico due to the low cost of labor.
"Although the casting costs in Mexico are significantly lower, we had to look at the entire package to finish our castings for assembly," said Mosack. "When the value-added processes such as machining and assembly are factored in with the shipping, the lead times grow tremendously forcing higher inventory carrying costs. When all of these factors are added together, the overall cost are higher. In addition, we are a family-owned business and some of the politics with building a plant in Mexico would have forced us to give up some of that ownership to Mexicans. We didn't want that to happen."
Conbraco also decided, according to Mosack, that its "Made in America" label was an integral part of the foundry and the overall organization and it didn't want to change that image.
The solution for Conbraco became a 90-acre site in Pageland the company had purchased 5 years earlier in anticipation of expanding one of its non-foundry divisions (which never happened). A relationship with the community already had been developed by the company's Apollo Ball Valve assembly plant, and the state and local governments were offering tax and employment credits in addition to reduced electricity rates through a local co-op. In addition, "the Matthews foundry already was shipping 80% of its castings to the existing Pageland plant for testing, machining and assembly, so the savings in handling costs were the clincher," said Mosack. Although the company took out a loan to finance the construction and equipment costs (with current production paying the loan off in 8 years, but projected production increases could result in a 4-year payoff), the land that was previously a watermelon patch became the drawing board for Conbraco's foundrymen.
By starting with a blank page, Conbraco was able to set up its new foundry how it wanted - with computerized automation and without compromises. Although the foundrymen knew the equipment they wanted and knew how the foundry must flow, they also knew that they needed outside help. With a brand new sand system and environmental controls and the need for a design that could accommodate an increase in outside jobbing work as well as capacity and technology expansion, Conbraco enlisted the help of Vulcan Engineering, Helena, Alabama, to ensure a trouble-free start-up. It was vital that Conbraco's foundrymen continued full capacity production at its Matthews plant throughout the new plants construction, and this outside help in engineering and design would ensure it.
"Casting demand never stops," said Sherman. "Even though our hearts and minds were focusing on the new plant, we couldn't fall behind on production at Matthews. The help in engineering and design allowed us to focus on both jobs successfully."
The groundbreaking that occurred in April 1997 resulted in a $25-million, 70,000-sq-ft foundry and 100,000-sq-ft machine shop that, according to Sherman, "hasn't had a major problem since the initial learning curve during start-up in early 1998."
Due to the tight layout of the plant in Matthews, space for its employees and the equipment was the number one priority in Pageland. It also was determined that the new foundry must have straight-line product flow that placed the core lines at the beginning of the plant and shipping and receiving at the end.
The heart of the new foundry design for Conbraco is its green sand system. At the old foundry, the sand system was worn out and not providing a consistent product. Vulcan took charge of this and designed a fully-automatic system composed of a new 250-ton storage unit, two mullers (one new and one from the old foundry), new sand makeup controls with auto analysis, a new overhead delivery system, and a new below-floor-level spill and shakeout return system. The system processes in excess of 1.5 million lb/day.
The sand system has a centralized PC in the sand lab (located above the foundry floor) with touch-screen control for start-up and real-time graphical representation of the entire system as well as each individual component. This PC is networked with Vulcan's system in Alabama, allowing the engineering firm to troubleshoot from its home base without sending engineers to South Carolina. The system maintains the makeup (water and bentonite levels, etc.) of the sand and the sand levels in the molding hoppers by automatic testers and sensors, while also screening the return sand before it is returned to the muller. Although the second muller is rarely used, Conbraco installed it so the system wouldn't ever be down due to maintenance.
Conbraco's shell core system, which is composed of six manual and 10 automatic machines, is controlled by a central PC in an office located on the plant floor. This PC-controlled core system was conceived by Conbraco and networked and programmed to the automatic core machines by a local software company. The core machines' PLCs were retrofitted with a module that has a cable running to the central PC. The PC monitors the core machines' cycle time, idle time, total life period and scrap rates and provides a graphical representation of the status of each machine. In addition, the curing time for each shell core machine is set on the PC to ensure a thorough processing of the sand. Although the main function of this PC-controlled core system is to maintain accurate count of core production and ensure steady product flow to molding, the system also maintains consistency in the coremakers' actions and processes.
Conbraco's molding is made up of six Hunter lines (two new HMP20Es, two HMP10Es from the old plant and two HMP10Cs from the old plant) that feed three Hunter turntables (a new HV20 and two HMH210s from the old plant) for indexing and pouring of molds. Melting is accomplished in four new 10,000-lb 500kW channel furnaces and two new 3000-lb coreless induction furnaces with a tapping temperature of 2100-2325F (1148-1273C) and pouring temperature of 2050-2275F (1121-1246C). The foundry melts primarily three copper-based alloys - 85% of its melts are CDA123, 13% are CDA115 and less than 2% are CDA245, a highly corrosion-resistant metal.
The workhorses of the Hunter molding lines are the two HMP20Es and the HV20 turntable [ILLUSTRATION FOR FIGURE 1 OMITTED], which are fed molten metal with stopper rod pouring by a 6500-lb pressure pour unit (bought used for the new foundry) that was redesigned by Duca Manufacturing & Consulting and is controlled by a CMI-Equipment and Engineering PLC system. While stopper rod pouring is common in iron foundries, it is unique for a brass operation due to the propensity for copper-alloy buildup around the nozzle. Conbraco, Duca and CMI eliminated this problem by heating the nozzle and developed an automatic system that pours 200 molds/hr (80% of overall production), with a pour weight from 20-75 lb and a pour rate of 12 lb/sec.
Beyond the buildup problem, the automatic pouring system had to overcome another obstacle - it must read and adjust to the varying sprue hole positions of the molds fed to the turntable by the two molding lines (often running different patterns). To accommodate this, the molder feeds new job data to the system during every pattern change and the PLC system pulls up the data for metal weight, rate of pour, sprue location, etc. to control the pouring system based on the mold production. Basically, the PLC system (because of the data entered) knows what kind of mold is being poured and adjusts the stopper rod pressure pour system automatically to properly pour the mold.
The control station for this pouring system provides display screens for monitoring and guiding the operator through the start-up and entering and retrieving of pouring data, as well as the controlling and monitoring of the pouring vessels pressurization. When the operator is first programming the PLC with the pouring data for each of the foundry's patterns, he uses a joystick networked to the stopper rod pouring to teach the pouring profile to the PLC. Once a successful pour has been performed by the operator using the joystick, the information is saved to the PLC to automatically imitate and use during production. The PLC system also has maintenance and production screens for the pouring and molding lines that provide information on hydraulics, pneumatics and mold production.
Once the molds are poured, they are transferred to vibratory shakeout, which was constructed underneath the turntables and below the plant floor, at the end of which initial manual inspection and separation of gating systems and castings is performed. The gating system is automatically removed from the castings during shakeout because of the kiss gating design and notches engineered into the casting. The gate-free castings are automatically fed into the shotblast, and then sent for in-house machining and final inspection. Conbraco constructed a 100,000-sq-ft machining operation adjacent to the new foundry where 100% of the foundry's castings are machined before assembly.
"The layout, material flow and efficient production of castings in this plant tell us the right decisions were made when designing the facility," said Mosack. "From the time we start an order, we ship 90% of our casting orders within 3 days. The operations are perfect for our captive product mix, but also open the door for outside jobs."
The plant's full first shift and partial second shift production cast more than 14.5 million lb of components in 1998 (a 5.8% increase over the old foundry production in 1997) and is projected to produce well over 15 million lb this year (a more than 10% increase over the old foundry's capacity). As Conbraco begins to build its non-captive customer base beyond the current 5% of production, the additional 20% of capacity available on second shift and the additional 50% of capacity available on a yet-to-be-started third shift will be used. With three full shifts, Conbraco projects a capacity of more than 25 million lb/year at the Pageland plant with its current technology. However, further enhancement of the current technology will provide even further gains in capacity.
When Conbraco set out to increase its brass casting capacity, it knew that environmental compliance was going to be important whether it expanded the plant in Matthews or built a new plant elsewhere. As the air and waste leaving the plant are being tested, the specifications for this greenfield brass foundry are steep (more so than for an addition to the existing plant at Matthews). In addition, Conbraco wanted to be viewed as a good neighbor to the Pageland community that works in the foundry and in the Apollo Ball Valve assembly and machining plant.
For Conbraco, the first concern was lead in the air. Since all the alloys poured at Conbraco are leaded, particles are released during melting, from the poured molds and during machining. The foundry built three large baghouses - one for the furnace area (45,000 cfm), one for the pouring stations (45,000 cfm) and one for the sand system (60,000 cfm) - to control the lead in the air and collect the airborne sand particles, as well as several smaller baghouses for the shotblast, grinding and machining areas.
Another area of concern was the neighboring communities and the noise generated by the foundry. In response, Conbraco added: silencers to its baghouses; curtains around its air blower; and a noise abatement wall, made of a special noise-dampening material, around its air compressor.
In addition, the foundry installed a sand reclamation system in-house to process 25% of its green and shell core sand, and it also has an arrangement with a local coremaker to reuse an additional 25% of its excess sand. One of Conbraco's priorities when it began to build on the former watermelon patch was to avoid adversely affecting the environment or community any more than those watermelon did.
"We have developed a relationship with South Carolina that has been beneficial to us and our community," said Mosack. "We want to keep it that way."
Conbraco Industries, Inc.
Pageland, South Carolina Foundry
Manufacturing Space: 170,000 sq ft.
Casting Data: copper-base alloys (primarily CDA123, 115, 245).
Expected 1999 Shipments: more than 15 million lb.
Processes: green sand molding; shell coremaking; induction melting.
Value-Added Processes: machining and assembly.
Markets Served: ball valves (95% captive) and valve castings (5% jobbing).
Year Established: 1997.
Top Staff Officials: Carl L. Mosack, president; Glenn L. Mosack, vice president-operations: David Sherman, foundry manager.
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|Title Annotation:||Conbraco Industries, Inc.|
|Comment:||From conception to casting: Conbraco's greenfield expansion.(Conbraco Industries, Inc.)|
|Author:||Spada, Alfred T.|
|Date:||Jul 1, 1999|
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