ANAHEIM, CALIF. — The market for metal coating of carbon fiber may be about to take off.
An Inco Ltd. unit and Composite Materials LLC are pushing hard to re-establish the market and supply compounders and injection molders with shielding materials, principally using high-tow carbon fiber. Also, Tokyo-based Toho Rayon Co. Ltd.'s carbon fibers subsidiary is producing limited quantities of nickel-coated carbon fiber.
The products can shield the electronics in cellular telephones and computer circuit boards and protect military electromagnetic-and radio-frequency-interference systems, as well as aircraft facing lightning strikes.
At Inco, custom compounders are conducting extensive evaluations of the new Incoshield-brand line of nickel-coated long-fiber pellets to shield electronics in computer, telephone and automotive-engine-control applications.
``We coat carbon fiber with nickel using a chemical vapor deposition process and do not damage the fiber,'' said Malcolm Rosenow, fiber products business manager in Wyckoff, N.J., for Inco Ltd.'s specialty powder products division. ``Our competitors use an electroplating process.''
Toronto-based Inco introduced the line initially in July.
At its Clydach facility near Swansea, Wales, Inco refines nickel and, using a nickel-bearing gas, deposits a high-purity coating on continuous fibers, usually of carbon, but potentially of aramid or fiberglass.
``We use thermoplastic resins instead of water-based sizing'' that requires pellet shearing, Rosenow said during the International Society for the Advancement of Material and Process Engineering Symposium/Exhibition, held May 5-8 in Anaheim.
Compatible resins include acrylic for ABS and polycarbonate/ABS, nylon types 12 and 6, polyphenylene sulfide, polycarbonate and polyetherimide.
``The concentrate pellets can go directly to the injection molding stage as a dry blend or a salt-and-pepper mix,'' he said. ``Melting the pellets disperses the fibers quickly. We use high-flow-rate or low-melt-temperature systems to achieve shielding performance, high connectivity and mechanical strength.''
Meanwhile, business prospects for its metal-coated graphite shielding material have prompted Composite Materials LLC to build in-house five customized plating lines by late summer.
``We will bring capacity to 1 million pounds per year of finished plated material,'' said Louis Morin Jr., chairman and chief executive officer.
The company's existing equipment and each of the new machines can produce 12,000-15,000 pounds per month.
Composite Materials makes chopped-metal-coated fiber that injection molders use for shielding applications. In an application with EMI and RFI implications, each B-2 bomber has about 1,000 pounds of the material in its outer ply.
Use of the Compmat-brand material for a cellular telephone housing, for instance, reduces processing and avoids the high-cost penalty of painting or plating.
``It's all done in one step with my operation and is 100 percent recyclable, and plating or painting is not,'' Morin said.
In a variation for a major aircraft maker, Composite Materials will make an initial 1,000 pounds of 40-60 percent copper-plated graphite with an outside flashing of five-millionths of an inch of nickel. Production begins in late May.
Custom compounders and laboratories will analyze the material, which has copper's thermal and conductivity properties but avoids the material's galvanic problem that can develop aboard an aircraft. The firm has trademarked Electronic Power Shield to identify the new material.
``Nickel on the outside forms a conductive oxide,'' Morin said. ``We found electricals are so good that [injection] molders want it for electrical housing to replace nickel-plated fiber.''
Composite Materials plans to sell the copper-nickel material for less than its nickel graphite.
``We actually save money and will pass that along to the customer,'' Morin said.
``Two of the world's largest resin manufacturers, one in Europe and one in the U.S., are currently developing a program that will encompass using our conductive fibers in their resins as a pre-compounded material,'' Morin said.
The program should surface in about six months.
Morin and New York investment banking firm Trautman Kramer Inc. acquired the business, then Cytec Industries Inc.'s Cycom metal-coated fiber division, in January 1996. It took three months to relocate the operation to a 32,000-square-foot facility in Mamaroneck, N.Y., from its site in Wallingford, Conn. Plating occupies 18,000 square feet.
Chopped fiber for thermoplastic reinforcement is the fastest-growing segment of the industrial carbon market, said Lance Hill, sales director in Muir of Ord, Scotland, for SGL Technic Ltd.'s carbon fibers division. He estimated the industry's annual growth at 15-20 percent.
He identified carbon-fiber-reinforced PC as the material in a cartridge carrier for a popular high-end computer printer. The technology has ``still not gone into domestic products,'' he said.
Hill said SGL can produce 2.2 million pounds of heavy-tow carbon fiber per year at facilities in Meitingen, Germany, and Inverness, Scotland — the latter being acquired in January from RK International Ltd.
SGL makes carbon fiber from PAN precursor fibers for thermoplastic compounds, electrical conductivity, industrial applications and structural applications in tows of 60,000-410,000 filaments. Uses include computer housings, drive shafts and concrete reinforcements.
Meitingen-based parent company SGL Carbon AG tops the markets for heat exchangers and carbon/natural graphite products, and aims to pass Akzo Nobel NV of Arnhem, the Netherlands, as the largest heavy-tow carbon fiber producer.
SGL plans to locate a carbon-fiber sales force at another unit's office in Valencia, Calif., Hill said.
SGL Carbon AG employs 6,541 and reported profit of $130 million on 1996 sales of $1.1 billion.