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Namitei: Deformed Wire for Cable Protection


We commonly think of metal wires and metal bars as being circular in cross-section, but the truth is that the cross-sections of metal wires used in the many diverse industrial products available in the world today take many forms. Depending on purpose, wires can be trapezoidal, flat, have indentations. Wires with non-standard cross-sections of this sort are known as ‘deformed wire’ or ‘deformed bars’.

Deformed wire and deformed bars are used in diverse applications, as material for manufactured and assembled products including parts for home electrical appliances, automobile parts, and material for screws and springs. Deformed wire and deformed bars are also processed into products and parts in diverse other sectors, from submarine cables stretching over tens of kilometers of ocean floor to accessories and even strings for stringed instruments.

The manufacturing process for deformed wire and deformed bars requires extreme precision. Wire must be manufactured so that wherever it is cut, at any point along its many meters of length, it has the same cross-section conforming to the same specifications. For wire that is mere millimeters in diameter, even the tiniest flaw can result in wire breakage; this is why the manufacturing process must be conducted with extreme care and accuracy. Although rarely seen, deformed wire is a concentration of superlative materials and high-precision micron-level technology that combine to ensure that the necessary levels of precision and accuracy are achieved.

Namitei impressed the whole of Japan with its production of 3-division protective steel wire, designed to protect submarine optical fiber cable from high water pressure. It supplied deformed wire as the pressure-proof layer for all the 150,000 kilometers of submarine cable laid by Japan in the period up to 2001; enough to go four times around the world. The 3-division protective wire has an innovative fiber-protective structure unique to Japan, with three fan-shaped steel wires wrap around each other to cover fiber. When protected by this wire, optical fiber can withstand water pressure of up to 800 atm at depths of up to 8000 m.

The technology behind this protective wire structure is now being applied to multiple other products. The low waste of material and low distortion of the wire makes it particularly appealing to product manufacturers; deformed wire for cold heading, which can help to speed up the production process, is showing improved performance in recent years.

Optical Fiber-Protective Wire: Traversing 10,000 km of the Pacific at 800 atm

The Namitei product that first impressed Japan’s manufacturing industry was the protective wire first completed 1986, used as the pressure-proof layer for the Third Pacific Ocean Submarine Cable. The wire is 55 km in length, with a fan-shaped cross-section, without a single join. The specifications of the cable order were extremely demanding: the wire was to be fan-shaped, with a margin of error of just 5 μm (5/1000mm, much narrower than the industry standard of 1/10mm at the time), and was to be delivered in just 2 weeks.

Namitei worked non-stop to deliver the cable to these highest of specifications. The trade firm that placed the initial order began to make further orders, for ever longer cables: 3000 m, 6000 m, 10,000 m, and finally for 55 km. The factory at the time was not able to handle the order, so Namitei designed and set up its own line in order to complete the order.
Material was ordered from Nippon Steel Corporation, a major steel corporation in Japan. Although at first dubious, Nippon Steel Corporation then ordered full mobilization of its research laboratory in material development.
The jet-nozzle developed by Namitei at that time, used upon cleaning off oil and other pollutants adhering to the wire during the manufacturing process, has today been developed into a high-speed cleaning system incorporating drainage, drying, and painting; it is now one of Namitei’s core products.

The investment made into this small factory in Higashi Osaka was huge, at 300 million yen, as the size of the company. Namitei has been manufacturing all protective pipes for Japan’s submarine cable ever since then.

Deformed Wire for Cold Heading: Towards a Cost-Cutting Revolution

Cold heading refers to the processing of bars with cylindrical cross-sections, without heating the bars, by applying pressure over a certain level. There is no cutting resulting in minimal waste of material, and there is no application of heat, meaning there is little degradation or distortion of the material. Data suggests that when cutting processes are used to manufacture a product, 29 g of material waste is generated for every 48 g of material. With cold heading, just 1 g of waste is produced per 20 g of material. 

Namitei uses deformed wire manufacturing technology on the circular cross-section material used in cold heading to form bar material in the approximate shape of the parts to be manufactured. By using this bar material, manufacturers can produce goods using fewer processes, with less waste, and at a reduced cost. In addition to this outstanding technology, Namitei can undertake all kinds of processes, including forming, cleaning, and coating, as well as their testing, covering the entire manufacturing process.
This consistency and comprehensiveness has allowed Namitei to build up strong relationships of trust with its customers, who know that Namitei can guarantee quality, timely delivery, and reasonable costs.

At present, Namitei also holds a large share in the market for winding shafts for automobile seat belts; as of 2010 70% of all Toyota automobiles were equipped with shafts manufactured by Namitei.
Namitei materials, therefore, have come to be exported in great numbers throughout the world via finished products manufacturers. Simply put, materials made in Higashi Osaka, a little factory city, have been sent around the world as integral parts of diverse products. Namitei will continue to uphold its made-in-Japan philosophy while meeting the ever increasing demand for cable and industrial product parts with high-quality products destined to travel the world.

Feb 27, 2012

About the author
Hiromi Jitsukata is a reporter for Japanest NIPPON
(Namitei Co.,Ltd.)*Japanese website