Foundrymen Focus on Ways to Improve Production at Regional.
During the 19 technical presentations given by foundrymen, suppliers and casting end-users, attendees were presented with new ideas relating to solidification modeling, patternmaking, computerized melt and sand systems, and the increasing expectations of casting customers. The 3-day supplier exhibition that featured more than 40 companies allowed attendees to peruse some of the newest innovations in metalcasting technology. Attendees also had the opportunity to visit local plants including Thomas Machine & Foundry, Marysville, Washington, Western Steel and NorthStar Casteel, Seattle, which all had undergone recent modernizations and expansions.
In one of the conference's panel presentations titled "Automation for the New Millenium," Cameron Girton, Spokane Steel, Tom Lochman, Romac Industries, Bill Gibb, NorthStar Casteel, and Robert Alexander, Western Steel, spoke about recent modernization projects at their foundries.
Girton's presentation focused on his plant's installation of a new flaskless nobake molding and pouring system for casting high- and low-alloy steel. Due to an increase in the size of components for its military, transportation and rock-crushing industry customers, the foundry was forced to shift from green sand to nobake molding.
During planning for the modernization in 1997, Spokane Steel visited six local foundries to develop an understanding of all the variables that must be addressed in the start-up of a nobake line. The variables Spokane identified were: pattern staging, fast-loop molding, coating, coresetting, automatic closing, pouring and cooling, shakeout and sand reclamation, material handling and throughput, a management control system, and system diagnostics.
The result for Spokane Steel was a flaskless system that handles mold dimensions from 32 x 38 x 8/8 in. to 48 x 84 x 23/23 in. The system has a production rate of 10 molds/hr for its maximum size molds and 20 molds/hr for its minimum size molds. The footprint for the system is 18,000 sq ft, and it requires six workers to operate.
"Most nobake systems have mold staging areas to build up molds for pouring," said Girton. "In this system, we have a 3-min cycle for molds."
Lochman discussed his foundry's upgrade to vertically parted high-production molding. In 1993, Romac's 5-year sales forecast projected a 70% increase in demand for cast iron couplings and fittings by its main customer, the waterworks industry. To meet this demand, it needed to expand its operation. In an engineering study, the foundry compared the advantages and disadvantages of adding two horizontal molding lines vs. adding a vertically parted molding line to the operation.
After examining sand delivery, melt rate, metal delivery, pouring, training, patterns, workers and a host of other factors, the foundry decided to add vertically parted molding. As a result, it required a new sand system (100 tons/hr with temperature control), two furnaces (one to hold and pour and one to melt) and a shakeout system. Initially, the foundry decided to manually pour this new high-production line. However, after experiencing consistency problems with the pours as well as metal delivery problems, the foundry switched to automatic pouring.
The keys to the foundry's start-up of the new system were the up-front planning and extensive employee training. In addition, the foundry purchased top-quality tooling for the new molding line that paid for itself in reduced finishing costs.
The third presentation on the panel by Gibb discussed NorthStar Steel's development of work cells in its cleaning and finishing operation to eliminate the bottleneck that had developed over the years.
The first step was to increase the space for the department from 40 x 60 ft to 120 x 100 ft. Then, the foundry eliminated its previous method of casting transport using forklifts and metal bins and added a conveyor system. Each worker then was given his own workstation with all the tools he needed to weld, grind or perform other finishing duties. Each cell also was equipped with the proper environmental equipment to improve air quality as well as ergonomics. These cells then were connected via a conveyor system. The result for NorthStar was improved flexibility for the workers and increased productivity.
The last presentation for the panel was Alexander's discussion on Western Steel's installation of a sand reclamation system. In 1998, the foundry installed a rotary reclamation system with a fluid bed classifier for its silica and zircon sand. The reclamation system has a throughput of 3.3 tons/hr and the foundry passes its sand through the system four times before reusing it.
The new system required an investment of $390,000. However, from 1998-99, the foundry saved $132,000 in new sand purchases.