Electroforming Underpins a Stronger, Greener EU

Some of the largest industries in Europe are becoming more efficient, more competitive and more secure as a result of a nickel electroforming, a simple process that can be used in a myriad of ways.

Take aerospace, for instance, an industry that has an annual turnover of Euro 80 billion and employs almost half a million people. Manufacturers in that field are reducing the weight and fuel consumption of their airplanes, while increasing lifespan, by using electroformed moulds to make precision parts.  Having a stronger, lighter wing edge, tail rudder or nose cone can make the difference between completing the sale of an airplane and being sent back to the drawing board.

Or textiles:  Europe has been able to remain competitive in this industry despite losing market share to less developed countries by guaranteeing high levels of precision and accuracy while increasing production levels. Nearly 15% of world-wide textile production takes place in the European Union (EU), supporting more than 2.5 million jobs, according to recent research by the Brussels-based Weinberg Group, a scientific and regulatory consulting firm.

In the case of textiles, it is not moulds but rotary screens that make the difference. Electroforming creates precise, finely patterned screens, which in turn transfer intricate and colourful patterns to textiles, wallpaper, and carpets.

The common denominator in both moulds and rotary screen technology is nickel. During the electroforming process, perfected in Germany in the mid-1800s, nickel or other metal in solution is electroplated onto a mandrel in order to reproduce the pattern on the mandrel’s surface. Although gold, silver and copper can all be electroformed, nickel is the metal of choice because it is versatile, has excellent heat, corrosion and abrasion resistance, and can be electro-deposited quickly.

Another lesser known application of nickel electroforming is the production of the millions of small, detailed holograms that are embedded in bank cards and notes as a security feature. Banks rely on electroforming technology to create the high precision moulds needed to protect the integrity of both cash and non-monetary transactions. The Weinberg groups says this kind of protection is  becoming more important as identify theft and other attacks on payment integrity continue, while the use of cash in the EU grows.

The billions of albums, films and computer games produced each year rely on a similar kind of high-precision replication technology enabled by electroforming. Roughly 20 billion CDs and DVDs are produced worldwide every year, according to the Content Delivery and Storage Association (CDRA), and each electroformed mould can produce about 100,000 of them. In the EU, entertainment applications of this sector generate annual sales of Euro 40 billion and support 400,000 jobs, according to the Weinberg Group.

The Weinberg report concludes that nickel electroforming supports the competitiveness of some of the largest industrial and service sectors in the EU. By supplying a platform for continued improvements in efficiency, sustainability and innovation, the process also plays a key role in reducing resource and energy consumption.

Air Force Memorial

The Air Force Memorial recently unveiled in Washington, D.C. ranks as one of the world’s largest structural applications of stainless steel along with the Dublin Spire in Ireland and America’s largest memorial, the Gateway Arch.

Consisting of three stainless steel spires reaching 64 metres into the air, the new memorial honours the millions of men and women who have contributed to the United States Air Force and its predecessors over the years, including 54,000 who died in combat.

Each spire has a ¾ inch (19 mm) skin of low sulfer (0.005% max) Type 316 stainless steel covering a core of reinforced concrete. The total weight of the spires is 7,200 tonnes, including 345 tonnes of type 316 plate.  

Air Force Memorial

Engineers involved in the design chose type 316 to prevent corrosion and allow the structure’s appearance to be retained over decades without the need for manual cleaning. Though Washington is not coastal, nor particularly polluted, the memorial is surrounded by three highways that use de-icing salt that could threaten a lesser material.

Type 316 also provides structural integrity to help withstand the tendency for the spires, which are curved, to sway in windy conditions.

“From a structural standpoint, the Air Force Memorial was very challenging,” says Catherine Houska, senior market development manager for TMR Stainless, the consulting firm chosen to provide advise on materials for the project. “When you have that kind of a curve unsupported, except at the base, it is going to tend to move even with the slightest breeze. There are very elaborate damping systems to prevent it from shaking apart.”

The “ball-in-box” damping system contains 13 20-inch-diameter lead balls, weighing 2000 pounds each, encased in stainless steel shells. The balls roll freely within boxes that are lined with synthetic damper pads. As the balls hit the pads, energy is dissipated and structural movement constrained.

The memorial was designed by the late James Freed, the internationally-renowned architect from Pei Cobb Freed, while global engineering firm Ove Arup developed the spire structure. The spires are meant to evoke the bomb –burst flying formation made famous by the United States Air Force Thunderbirds.

Construction commenced at the beginning of 2005 and was completed in the autumn of 2006. The total cost for construction was more than US$30 million.

Is a Heavy Metal Toxic?

The lack of a clear definition for the term “heavy metal” and its common use as a substitute for 'toxic substance' continue to cause confusion in public debate.

Once used to describe a large gun, the term now has a least 38 different definitions that - depending on the scientific literature source - relate to anything from density and atomic weight or number to chemical properties or toxicity, according to “Heavy metals” – a meaningless term?”, a 2002 International Union of Pure and Applied Chemistry (IUPAC) report.

As a result, lists of heavy metals may differ from one set of regulations to another and the term is often used without specifying the metals included in the list. 

“What is surprising is the persistence of the term and its continuing use in literature, policy and regulations, with widely varying definitions leading to confusion of thought, failure in communication, and considerable waste of time and money in fruitless debate” wrote J.F. Duffus, author of the report published in Volume 74 of Pure and Applied Chemistry. His complaint still rings true today.

There is also a tendency to assume that all of the heavy metals and their compounds have toxic properties, a false assumption says Bruce McKean, Director of Stewardship and Sustainable Development for the Nickel Institute.

He argues that any substance will be toxic at a certain level because toxicity is a function of dose. And just because a metal is dense or “heavy” does not mean that it has more toxic potential than a relatively “light” metal.

Bioavailability – the degree of availability of a substance to be taken up by biological organisms – is also an important consideration when metals are classified based on assessments of toxicity, according to Duffus.

Under most traditional definitions, nickel would be considered a heavy metal because it is relatively heavy (atomic number 28) and dense (specific gravity 8.9), compared to other elements.

But there are more than 150 nickel compounds in industrial or commercial use, each with different biochemical characteristics and potential for toxicity. Grouping them together with pure nickel is misleading.

Duffus thought that the term “heavy metal” would soon become obsolete because it no longer had any consistent meaning. But four years after he wrote his paper, the term is still widely used and there continues to be a misguided tendency to group pure metals and their compounds together.

For example, sodium metal and sodium chloride are considered by the usage to be equivalent, but the pure metal can cause life-threatening damage when swallowed, while sodium chloride (salt) is an essential part of the human diet.  Similarly, chromium and its alloys are safe for medical and dental applications, but chromate has been identified as a carcinogen. And the list goes on.

Duffus suggested metals be classified according to their position on the periodic table, in which elements can be grouped according to chemical reactivity and, by association, behaviour in the environment. A more precise classification would group metallic elements based on their Lewis acidity, or net positive charge, which determines their interaction with living systems.

For example, it is known that certain “soft” metals similar in size to the calcium ion are likely to cause harmful changes in membrane structure because of their affinity for phosphate groups and non-oxygen centres in membranes.

“Such a classification would permit interpretation of the biochemical basis for toxicity. It would also provide a rational basis for determining which metal ionic species or compounds are likely to be most toxic,” Duffus wrote.

Water Tower as Eye Candy

When the city of Chattanooga, Tennessee decided to capture and reuse its stormwater to irrigate municipal gardens, urban planners envisioned a water tower that would serve as a monument to this contribution to sustainability.

Aesthetics were a key factor in the design because the water tower was to be located in the middle of a recently revitalized downtown. Under these circumstances, 304 stainless steel won out over more conventional materials - such as lined carbon steel or reinforced concrete - as the building material of choice. 

Aerial View of Downtown Chattanooga, Tennessee

“This tank is in a growing section of town and it had the potential to be an eyesore and an unwanted fixture in that area,” says Tom Schull, marketing manager for Chattanooga Boiler and Tank Co., the company that built the tank. “The designers were able to overcome that. It doesn’t look like a water tank; it looks like a work of art.”

But eye appeal was not the only reason Consolidated Technologies Inc., the engineering contactor on the water tower project, proposed stainless steel. Carbon steel tanks are much more susceptible to the corrosion caused by fluctuating water levels and, as a result, incur higher maintenance costs.  

“When (the city) compared the painting, lining and maintenance issues over the lifetime of the product, that became a factor in the choice of bid,” says Schull.

The stainless steel option was doubly cost-effective because the builders were able to assemble the tank at their nearby factory and avoid the expense and hassle of painting a carbon steel tower in the middle of a busy downtown core.  In fact, Chattanooga Boiler came in as the lowest bid on the project, at US$159,947, with their stainless steel tank proposal, according to city records.

In recognition of all these factors, the Steel Plate Fabricators Association awarded the Chattanooga public works department the “Steel Tank of the Year” award in 2002 for devising a practical alternative to stormwater retention. 

The 75-ft.-tall 16-ft-diameter tank is part of a larger under-and-above ground water storage system that can store up to 865,000 gallons of water within concrete pipes, box culverts and within the tank itself, which has a capacity of 105,000 gallons.

Two submersible pumps force water from the underground storage through sand filters to remove solids before the water enters the aboveground tank. The filtered gray water is then used to irrigate the streetscape, flush and drain stormwater catch basins and water trees and shrubs in the downtown area.

The unique water tower sits in the middle of a 70-acre landscaped plaza that is bounded on all sides by city streets. In another nod to curb appeal, the tower flares out at the top to a diameter of 26 ft.

“We’re not architects, but we’re pretty proud of (the tank),” says Allen Stephens, senior vice-president of Consolidated Technologies Inc., who managed the project on behalf of the city of Chattanooga. “We were able to take something utilitarian and turn it into something that is aesthetically pleasing.”

Find New Markets Fast, Battery Makers Told

The future for nickel batteries lies with electric vehicles as well as other potential applications such as hobby batteries, telecom and electric bikes, says a new report on the global nickel battery market from Frost & Sullivan, a New York-based research service.

Traditionally, the industrial sector has been the main end user of nickel batteries, including nickel-cadmium (NiCad) and nickel metal hydrides (NiMH), because the batteries are relatively inexpensive, resistant to harsh environments and temperature flucuations and have high discharge rates. Recent growth in portable devices, such as laptops and mobile phones, has diversified the market. 

However, the report warns that unless nickel battery manufacturers make a significant investment in research and development, they risk losing more market share to newer battery chemistries that have enhanced features such as longer run times, decreased weight and compact size. These newer battery chemistries include lithium-ion (Li-ion), lithium ion polymer (Li-ion Poly) and lithium sulpher.

“”With the threat of substitution by newer battery chemistries, there is an urgent need to incorporate additional features such as miniaturization, portability and greater energy density,” say the authors of World Nickel Battery Markets. “Further, rigorously finding new applications or geographical regions in order to ensure market expansion remains the prime challenge for future sustainability.” 

For new geographic markets, the report suggests manufacturers target countries outside the declining nickel battery markets in Europe and North America. The Asia Pacific region, where cheap labour, excellent infrastructure and abundant raw materials ensure higher profit margins, is singled out for its potential for growth. Lower production costs give these countries particular leverage during the current high commodity price environment.

Revenue in the nickel battery market was $1.77 billion in 2004. The researchers expect this number to decline to $1.69 billion by 2011 unless new markets are developed soon.