Technora para-aramid fibre used in deep sea probe cable

23 April 2009, Osaka - Teijin Techno Products Limited has announced that its high-performance Technora para-aramid fibre has been adopted by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) for the 160-metre secondary cable of a deep-sea probe named ABISMO (Automatic Bottom Inspection and Sampling Mobile), which is being used to explore the world's deepest oceans.

The Abismo secondary cable was developed by JAMSTEC and Furukawa Electric Co., Ltd. in cooperation with Teijin Techno Products. Teijin says that Technora fibre was chosen due to its superior tensile strength, water and chemical durability, fatigue resistance to prevent degradation caused by compression or distortion as the cable is released and retrieved while the vehicle is in operation, making it ideally suited to the extremely harsh environments visited by the underwater craft

ABISMO holds the current record for the deepest dive (10,258 meters) by an unmanned vehicle, which it set in the Challenger Deep of the Mariana Trench, the world’s deepest ocean, in June 2008. It consists of a launcher and a vehicle, which are connected to each other via the secondary cable. The launcher holds the vehicle during descent and ascent, and then releases the vehicle near the seafloor to conduct research according to commands issued from the support ship.

Technora, a proprietary material first commercially produced by Teijin in 1987, exhibits the following competitive features, the company says:

-Tensile strength: Eight times stronger than steel and three times stronger than fibreglass, polyester or nylon yarn of the same weight.

-Fatigue resistance: Resistance to fatigue under conditions when conventional high tenacity fibres tend to lose significant strength if subjected to abrasion, flexion or extension.

-Dimensional stability: Minimal elasticity of just four to five percent thanks to a rigid molecular structure as well as low coefficient of thermal contraction/expansion.

-Heat resistance: Withstands long-term use at 200°C, maintains more than half of its room-temperature strength at 250°C, and starts to disintegrate only from 500°C.

-Chemical resistance: Resistance to acid and alkaline solutions, organic solvents, hydrolysis (both sea water and water vapour), and moist heat up to 180°C.

About Teijin

Teijin is a global technology-driven group operating in five main fields: synthetic fibres; films and plastics; pharmaceuticals and home health care; trading and retail; and IT and new products. Teijin Limited is listed on the Tokyo and Osaka stock exchanges and has a market capitalization of USD 4.1 billion. The company had consolidated sales of USD 10.3 billion in fiscal 2007, and employs approximately 19,000 people worldwide.

Images courtesy of JAMSTEC