New fiber production methods

The growth of polyolefin fibers continues. Advances in olefin polymerization provide a wide range of polymer properties to the fiber producer. Inroads into new markets are being made through improvements in stabilization, and new and improved methods of extmsion and production, including multicomponent extmsion and spunbonded and meltblown nonwovens. 

A recent successful application of carbon/carbon composites is the tool for superplastic forging of titanium illustrated by Figure 6 tubes up to 1.5 m in length can be forged at temperatures up to 1000°C, thus offering a rapid alternative fabrication technique to present production methods, e.g., riveted tubes (15). Contact brushes for electrical commutators, made with carbon fibers and carbon/carbon composites (16), are opening another new field of application. Furthermore, pistons in diesel engines have been proposed to be made from carbon/carbon composites (17). 

During the last years a new application of synthetic glues has been developed, the so-called production of hon-woven materials, in which the stmcture is formed by gluing of individual fibers. This method is used in the production of the clothes and preparation of electro- and heat-isolation materials by a simple and cheap technology. In mass production, a preparation technique using glue is simpler and economically advantageous compared to other possible techniques. 

The manufacturing of adaptive structures requires new production methods that need a lot of experience and expertise for the fabrication of complex systems with embedded or applied actuators and sensors. Patch-like sensors such as 1-3 piezo fiber composites are quite appropriate to be attached to the surface or to be integrated into lightweight multilayer constructions. The bond layer between the piezo element and the base structure determines the transfer behaviour of strain, vibrations and acoustic waves from the actuator to the structure and from the structure to the sensor. Local stress distributions can strongly be influenced by the bonding technique. 

The direct linking of carbon nanotubes to graphite and the continuity in synthesis, structure and properties between carbon nanotubes and vapor grown carbon fibers is reviewed by the present leaders of this area, Professor M. Endo, H. Kroto, and co-workers. Further insight into the growth mechanism is presented in the article by Colbert and Smalley. New synthesis methods leading to enhanced production... 

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