2001 Foundry of the Year: Neenah Foundry Co.

By 'thinking outside the box' while optimizing its green sand systems, this foundry has begun to validate a new process that dramatically reduces production costs and mold emissions and increases mold quality.

Innovation is a game of chance. Sometimes it leads to success for foundries with increased production efficiencies and reduced costs. Sometimes it leads to "learning experiences" and an "investment" ready to be shoved out the back door. Whichever the case, in today's world of intense global competition when the difference between winning a job and "closing your doors" can be separated by pennies, the key for foundries is to continue to search out innovation. It can provide the needed "leg up" on the competition.

Neenah Foundry Co., Neenah, Wisconsin, believes it is one of the foundry industry innovators.

"It is critical to search out new technologies and processes that can improve your plant's operations and contain costs," said Charles Kurtti, executive vice president. "This is a big part of the reason why our foundry can compete and succeed in the markets we do. This is our key now and our key to the future."

To Neenah, innovation is a part of doing business. As the recipient of the 2001 AFS Plant Engineering Award, this fact was brought to the forefront. Neenah's most recent innovation is the advanced oxidation technology it installed and validated on the green sand systems in its two plants. Driven by a need to reduce green sand emissions, the foundry pursued this unproven

technology and developed a success story that resulted in reduced production costs and emissions and increased mold quality.

This article first takes a look at Neenah's sand system optimization program that used techniques foreign to most foundries, including advanced oxidation technology. In addition, in two sidebars--"Neenah Grows Through War-Time Booms" and "Reshaping Production for the Future at Neenah"--the article looks at Neenah's history of growth and the current production practices employed.

Neenah=Innovation

Neenah's dedication to innovation is exemplified in its quest to optimize its sand systems. This process started in the early '90s when Neenah required a solution to increased demands for emissions reductions.

The federal Maximum Achievable Control Technology (MACT) standard and the Wisconsin Best Available Control Technology (BACT) standard were under development to reduce levels of hazardous air pollutants (HAPs) from foundries. Emission limits exist in Wisconsin for organic HAPs. For example, Wisconsin foundries are limited to emitting 300 lb of benzene per year. If these limits cannot be obtained, a variance from the regulatory agency is required. This variance requires demonstrating that the production process meets BACT. Since many of the larger iron foundries in Wisconsin would exceed various organic HAP limits, it became necessary to define BACT specifically for Wisconsin foundries.

The first emissions control-technology option reviewed was the addition of stack burners to incinerate the HAPs. However, foundries move large quantities of air to maintain indoor air quality, which dilutes the concentration of organic HAPs to low levels. As a result, incineration is an unattractive control alternative. In addition, the Wisconsin Cast Metals Assn. estimated the cost of operating incinerators to be "tens of thousands of dollars per ton of VOC emissions burned."

"This was an unacceptable solution for Neenah because of the great disadvantage it would place on us in the global market," said John Andrews, vice president of manufacturing.

Neenah management then decided to pursue a "sand optimization" approach to reducing emissions.

"The goal was to look at the entire sand system and search for ways to improve control, reduce raw material usage and reduce emissions without harming the sand properties or casting quality," said Andrews.

The foundry first addressed Plant 3's sand system. The first change the foundry made was to modify its dust collection drops in critical areas of the return sand system by placing air bleedins in the ductwork. This allowed the foundry to control the amount of suction at each collection point. For the most part, the dust collection system suction was reduced to pulling in only the material (fines, dust, etc.) that it didn't want in the sand system.

The aspect of the sand system most affected by these changes was an increased level of combustibles in thesand. This allowed Neenah to reduce the percentage of seacoal and increase the clay portion in the preblend added to the sand. (This automatically reduced preblend usage). With the reduced suction, the active coal also was staying in the system longer, and the percentage of sand on the 140 screen increased (this previously was evacuated to the baghouses). Although this method served to increase the fines in the sand from 3.54.5%, the foundry experienced no ill effects during molding.

The next step for Neenah in its sand optimization was to reduce the combustible level in its sand from 5.5% to 4. During a period of 13 months, the foundry reduced the coal pre-mix seven times by no more than 2% at a time (from 32% of premix to 22%). Additionally, the bentonite control levels were reduced by 10%. Although the foundry reached 4% on its combustibles, due to product mix changes and increased core sand entering the sand system, it has raised this figure back to 4.4%.

Advanced Oxidation

The final step for Plant 3 was the addition of a Sonoperoxone system (advanced oxidation technology). This technology adds advanced oxidants to the sand through the sand system's water supply. Advanced oxidation technology was initially developed in the water treatment industry and has been introduced to green sand casting as a means to clean the clay, seacoal and other organic additives, and reactivate them.

Advanced oxidants are a combination of intense ultrasonically treated water, less than 10-ppm ozone and hydrogen peroxide. In foundries, this advanced oxidant water is added to the green sand system wherever water is conventionally added, such as sand coolers, blenders, and mullers. It has been hypothesized that advanced oxidants "clean" the clay and seacoal in the sand system. The clay then s better able to adhere to he silica grains and other organics that comprise the mold, and the seacoal is able to better adsorb HAPs being emitted from incomplete combustion of organic material in the sand system.

"When the advanced oxidation is turned on, there is an immediate and dramatic reduction in the smoke from the mold line," said Andrews. "In addition, the molding supervisor sees a measurable reduction in the premix requirement."

Neenah took the next step with the advanced oxidation system (on a prototype level) and began reintroducing baghouse dust material into the sand system. Green sand baghouse dust can contain up to 40% clay. However, previous experience had led Neenah to be cautious in this next step.

"Green sand systems in foundries are critical and must be given due attention and respect," said Andrews. "To haphazardly throw dirt and dust in is a mistake."

With this new process, baghouse dust is mixed with water. The "blackwater" mixture then is blasted with intense ultrasonic energy and advanced oxidants are added. This mixture is sent to a clarifier (separation tank) in which the fines are removed from the clay and advanced oxidant water solution. The advanced oxidant blackwater then is sent to the sand cooler and mullers. The clay removal from this dust is effective as the waste fines contain only 4% clay. Neenah only used baghouse material from a collector drawing from the green sand system and slowly increased the addition rate of dust to the system.

Although the exact science involved in the reactivation of the clay and seacoal is still under investigation, the results were clear to Neenah with its R&D Plant 3 system. Compared to its baseline data (from before the sand system optimization program was begun), the foundry realized a 30% reduction in premix usage. The foundry also saw up to a 30% reduction in new sand additions because it doesn't need to add new sand in comparable levels to new bond. In terms of green compressive strength of the sand, the foundry has seen an increase of up to 6 psi with advanced oxidation. In terms of emissions, the foundry reports a 75% reduction in volatile organic carbons since 1995, and up to a 35% reduction in benzene emissions (depending on cored vs. uncored castings).

These positive results were affirmed by little to no change in green sand system operating conditions such as loss on ignition, methylene blue clay, compressive strength and compactibility, and no increase in casting scrap levels.

This leads to possibly the most important benefit to Neenah since the introduction of advanced oxidation--sand system predictability.

"Our sand system is easier to manage," said Andrews. The foundry isn't constantly introducing new sand and bond to makeup for lost properties.

"The greatest advantage added by the advanced oxidation system is that it makes the sand system more predictable," said Jeff Goudzwaard, senior environmental engineer. "It allows the foundry to focus on the production process and ensure casting quality."

In February 2000, Neenah added a full-scale advanced oxidation system to its Plant 2 sand system feeding a high-production vertically parted mold line. For this system, Neenah treats the water being added to the sand mullers and coolers and is performing a full-scale reintroduction of baghouse material into the molding system. During the first year of operation, the plant has seen similar reductions in bond additions to this sand system as well as a 50% reduction in VOC emissions and a 33% reduction in benzene emissions. Neenah has made initial plans to add a full-scale advanced oxidation system to Plant 3 to replace the current R&D system.

Neenah's success with advanced oxidation illustrates the benefits of becoming an innovator. It has found a technology and process that gives it "a leg up" on the competition and the challenges facing metalcasters in the 21st century.

Neenah Foundry Co.

Neenah, Wisconsin

Metals Cast: Gray (class 30 and 35) and ductile (grades D4018, D4512, D5506 and D7003) iron.

Mold Capabilities: Green sand.

Core Capabilities: Phenolic urethane coldbox, phenolic urethane nobake and shell.

Melt Capabilities: Cupola.

Size: 440,000 sq ft.

Key Markets: Municipal/construction (manhole covers, tree grates, etc.) and industrial (heavy truck, agriculture and compressor).

2001 Shipments: 180,000 tons.

Employees: 940.

Year Founded: 1872.

Plant Officials: Bill Barrett, president and CEO; Chuck Kurtti, executive vice president.

Neenah Crows Through War-Time Booms

The history of Neenah began in 1872 when William Aylward hired two employees and established Aylward Plow Works (in the area that became Neenah, Wisconsin one year later) to produce plow blades for the local farming community. By 1881, the firm had added cast iron stoves, bean pots, barn door rollers, sugar cauldrons and sleigh shoes to its product line and fed off the post-Civil War boom of the economy. In 1904, the firm decided to enter a new market that would become its focus for the next 97 years--municipal construction castings such as manhole covers and sewer grates.

After moving the manufacturing facility to a different area in Neenah and renaming the company a couple of times (due to the death of William Aylward), the Aylward family finally settled on the name Neenah Foundry Co. in 1922. In 1928, the foundry further diversified its business with the decision to manufacture industrial castings for paper mills.

While the Great Depression of the 1930s became the beginning of the demise for many manufacturers, Neenah Foundry's future became rock solid during this decade. Federal Government Work Projects Administration programs opened the market for private manufacturers of construction castings. Neenah redirected all its efforts and resources to this market and emerged from the depression as the nation's primary producer of construction castings.

Following another postwar boom after the end of World War II, Neenah installed its first automated molding line (with an overhead sand system) in 1946. During the '50s and '60s, the firm doubled its employment to more than 700 and increased sales by more than 400%. Another milestone for Neenah was the introduction of ductile iron production in 1957. In 1960, Neenah built its Plant 2 operation, which was, at the time, the largest construction casting facility in the world, In 1967, Plant 3 was built to produce cast components for heavy manufacturing.

Reshaping Production for the Future at Neenah

After surviving the industry shakeout of the early '80s, Neenah re-engineered both Plants 2 and 3 during the decade to prepare itself for both foreign and domestic competition. In 1985, Plant 2, which is the gray iron casting facility, saw the addition of a green sand cope and drag air impulse molding line to serve as the workhorse of its construction casting product line. This line uses 44 x 50-in. flasks with 10-in. cope and 16-in. drag heights and produces 85 mold/hr. In 1989, the foundry added one of the world's largest (at the time) vertically parted, high production flaskless green sand lines with automatic core setting and pattern change, pattern heating and the capability of producing 260 molds/hr (uncored) at 31.5 x 37.4 in. Plant 2 also utilizes one hydroslinger cope and drag molding line with flasks measuring up to 52 x 84 in. to produce specialty castings for the construction market.

The Plant 3 operations were completely rebuilt in 1987 to perform high-production ductile iron casting for the industrial marketplace. The foundry also installed vertically parted, high production flaskless molding machines--one similar to that in the gray iron foundry and one smaller with automatic core setting. The smaller line produces molds sized at 21 x 25.6 in. at a rate of 410 molds/hr (uncored).

"We were reshaping for our future," said Kurtti. "Neenah needed to be focused as a high-production operation geared toward efficiency in melting and molding. Once the equipment and processes were in place, the new target markets (ductile iron industrial castings) would follow."

The '90s proved to be a decade of business challenges for Neenah. In 1993, the foundry decided to shut down Plant 1 as the facility's future was questionable due to market concerns and capital requirements. In April 1997, the Aylward family (5th generation) sold Neenah to Citicorp Venture Capital. This launched a string of acquisitions from April to December 1999, including Deeter Foundry, Lincoln, Nebraska; Mercer Forge Co., Mercer, Pennsylvania; Dalton Corp., Warsaw, Indiana; Cast Alloys, Inc., Carlsbad, California; and Gregg Industries, El Monte, California. In September '98, Neenah merged with Advanced Cast Products, Inc, Meadville, Pennsylvania, to form a 9-company group that offers casting (green sand, nobake, lost foam and investment molding) and forging services in various ferrous and nonferrous alloys. More importantly, the acquisitions and mergers made this group one of the largest municipal construction casting suppliers in North America and provided a larger foundation in other industrial compone nt markets such as heavy truck, compressors, automotive/light truck, railroad and mining.

Neenah Today

The Neenah Foundry of today operates as two separate plants with different objectives working to achieve the same common goal.

"We are two different plants that work well together," said Steve Lewallen, director of engineering and management information services. "We need to feed off of each other's successes and learning experiences to benefit the overall team."

Plant 2 is the gray iron plant with its production primarily focused on the municipal construction casting market.

Melting in plant 2 is performed by two hot blast cupolas with oxygen injection. Pouring on the automated mold lines is accomplished with 10-ton horizontal channel pressurized stopper rod furnaces with in-stream inoculation and the hydroslinger line uses manual ladle pouring. Core systems used by this plant as well as by Plant 3 (the core machines are stationed in both plants and supply both plants depending upon demand) include 10 coldbox core systems that blow cores from 9-350 lb., and two shell core systems producing cores from 35-70 lb.

In 1985 when the cope and drag line was installed in the gray iron plant, the molding line was outfitted with the latest PLC technology available at that time. In late '99, the foundry upgraded to the newest PLC controls and networked the molding line to an internal network that had been previously established with the three vertically parted molding lines, the pressure pour furnaces and the sand systems during the re-engineering of Plants 2 and 3 in the late '80s. This management information system allows Neenah management to review the operations of the various departments within the foundry from their desks to determine job and equipment status. According to Neenah, each of these automation measures is geared towards creating measurement systems that allow cost competitive operations.

Neenah states that a significant portion of the municipal/construction castings purchased in the U.S. are from offshore, but this figure has not grown or contracted recently. Globally, Neenah has thousands of customers for its municipal/construction business throughout North America, South America, Europe and Asia.

"In this market, many buyers prefer to purchase domestic products because of consistent price and quality," said Tim Koller, vice president of construction sales. "Is best price always the lowest price? It often depends on the dynamics of the customers needs, such as the availability of the product."

Like other iron foundries, Neenah sees the shrinkage in demand for gray iron castings and the increase in demand for ductile iron castings. "It is our job to understand the markets and provide our customers with the engineering support and the facilities to satisfy their future casting needs," said Kurtti.

Neenah's Plant 3 is its ductile iron plant and is dedicated primarily to the industrial side of the business. Melting in this plant also is performed by a cupola that duplexes into two 60-ton holding furnaces. Ductile iron is produced utilizing the tundish treatment process. The treated ductile iron is ladle-fed to either a 10-ton or a 6-ton horizontal channel furnace for pressurized stopper-rod pouring on the vertically parted mold lines. The ductile iron pour furnaces are kept under a nitrogen atmosphere and utilize laser pouring.

In the cleaning and finishing areas of Plants 2 and 3, Neenah has made two recent advancements--bar coding/automatic data collection (in 1997) and robotic finishing (in 2001). The bar coding system provides the ability to track work-in-process cast components from molding to shipping. A portion of this system provides real time information to employees for cleaning parts on the shop floor. The automatic data collection systems provide Neenah management the ability to track and monitor department backlogs and product flow. Production bottlenecks are identified and can be traced to specific jobs.

The addition of robotic cells to Neenah's cleaning and finishing is targeted at reducing costs to better compete in the global marketplace.

Neenah also has expanded its customer service to include value-added services such as casting design.

"We offer the up-front engineering that our segment of the market wants," said Pat Neitzel, manager of industrial sales. "Neenah is looking for new applications by redesigning weldments and fabrications to casting."

One example of new ductile iron business for Neenah is an air scoop for agriculture combine equipment it is casting in 80-55-06 ductile iron. Previously manufactured as a weld-ment, Neenah redesigned it for casting at a 40% cost savings for the customer. This component was named an Honorable Mention in the 2001 Engineered Casting Solutions/AFS Marketing Div. Casting Contest.

Neenah Named 2001 modern casting Foundry of the Year

modern casting selects its Foundry of the Year based on the winner of the AFS Plant Engineering Committee's (1-D) Plant Engineering Award. The AFS Plant Engineering Award is open to all foundries in the U.S., Canada and Mexico, and judging is performed by members of the 1-D committee.

For the 200l award, Neenah's nomination form stated the following about the foundry:

"The time, effort and cost to bring validity to the advanced oxidation process, now accessible to all foundry operators, is just reason for this award. The results of this effort by Neenah will have far-reaching impact on foundry operating cost and casting quality, along with substantial reductions in emissions expelled into the air and work environment."

Past winners of the AFS Plant Engineering Award have included GM Saginaw Malleable Iron, Saginaw, Michigan; Waupaca Foundry, Inc. Tell City, Indiana; and Charlotte Pipe & Foundry Co., Charlotte, North Carolina.

Nomination forms for the 2002 AFS Plant Engineering Award are available via the modern costing website at www.moderncasting.com. The AFS Plant Engineering Award winner will be announced at the 2002 AFS Casting Congress in Kansas City. modem casting will then profile this foundry as its Foundry of the Year in the July 2002 issue.