Fiber developments natural fibers

Camille and Henry Dreyfus developed the first commercial process to manufacture cellulose acetate in 1905 and commercialized the spinning of cellulose acetate fibers in 1924 in the United States. At that time, the only other human-made fiber was viscose rayon, which was still in its early stages of commercialization. The main textile fibers were natural fibers cotton, wool, silk, and flax. Cellulose triacetate textile fiber was commercialized later in the 1950s. The tremendous technical effort by the Dreyfus Brothers resulted in more than 300 patents describing such significant inventions as the dry-spinning process and disperse dyeing. 

In order to develop natural fiber-reinforced polymer composites, the primary focus should be given to the nature of the interface between the natural fiber and the polymer matrix. A fundamental understanding of fiber-fiber and fiber-matrix interface is critical to the design and manufacture of polymer composite materials because stress transfer between load-bearing fibers can occur at the fiber-fiber interface and fiber-matrix interface. In wood-polymer composite systems there are two interfaces that exist, one between the wood surface and the interphase and one between the polymer and interphase [1]. Therefore, failure in a composite or bonded laminate can occur as follows (i) adhesive failure in the wood-interphase interface, (ii) the interphase-polymer... 

In terms of the number of scientists and engi neers involved research and development in polymer chemistry is the principal activity of the chemical in dustry The initial goal of making synthetic materials that are the equal of natural fibers has been more than met it has been far exceeded What is also im... 

Synthetic polymers have become extremely important as materials over the past 50 years and have replaced other materials because they possess high strength-to-weight ratios, easy processabiUty, and other desirable features. Used in appHcations previously dominated by metals, ceramics, and natural fibers, polymers make up much of the sales in the automotive, durables, and clothing markets. In these appHcations, polymers possess desired attributes, often at a much lower cost than the materials they replace. The emphasis in research has shifted from developing new synthetic macromolecules toward preparation of cost-effective multicomponent systems (ie, copolymers, polymer blends, and composites) rather than preparation of new and frequendy more expensive homopolymers. These multicomponent systems can be "tuned" to achieve the desired properties (within limits, of course) much easier than through the total synthesis of new macromolecules. 

Because of their inherently high efficiency on dusts in all particle-size ranges, fabric filters have been used for collection of fine dusts and fumes for over 100 years. The greatest limitation on filter application has been imposed by the temperature limits of available fabric materials. The upper limit for natural fibers is about 90°C (200°F). The major new developments in filter technology that have been made since 1945 have followed the development of fabrics made from glass and synthetic fibers, which has extended the temperature limits to about 230 to 260°C (450 to 500°F). The capabihties of available fibers to resist high temperatures are still among the most severe limitations on the possible applications of fabric filters. 

A survey about the possible applications of natural fibers in automobiles, as presently developed, is shown in Fig. 1. 

Extrusion press processing (express processing) was developed for the production of flax fiber-reinforced PP at the research center of Daimler Benz (Ulm, Germany) [62]. In this processing, natural fiber nonwovens and thermoplastic melt-films are alternatively deposited in a tempered molding tool and molded afterwards. The thermoplastic melt-films are laid on by a mobile extruder. If thi.s process is optimally adapted to the element, a single passage by the extruder suffices. The structural order consists of three layers two layers of... 

The mechanical properties of composites are mainly influenced by the adhesion between matrix and fibers of the composite. As it is known from glass fibers, the adhesion properties could be changed by pretreatments of fibers. So special process, chemical and physical modification methods were developed. Moisture repel-lency, resistance to environmental effects, and, not at least, the mechanical properties are improved by these treatments. Various applications for natural fibers as reinforcement in plastics are encouraged. 

Yet, the development of processing and modification methods is not finished. Further improvements need to be expected so that it might be possible to substitute technical fibers in composites even more widely. Natural fibers are reusing raw materials and they are recyclable. When recognizing the need for recycling and preserving natural resources, such a substitution is very important. 

For many applications, however, plastics have superseded metal, wood, glass, natural fibers, etc. Many developments in the elec-... 

More akin to silk yarns, continuous filament POY produces lighter fabrics, typically of 100 % PET. Such yarns have provided a fertile field for imaginative engineering of cross-sectional shapes, fiber sizes and combinations of color and texture. An entire field of specialty filament yarns known as Shingosen has been developed in Japan, providing novel and luxurious fabrics that cannot be duplicated with natural fibers. 

Although fibers can be classified in numerous ways, in terms of present-day technology, they are fundamentally classified as(l) natural libers, and (2) synthetic libers. The principal natural fibers are cotton, wool. and. to a much lesser extent, silk. liax. and mohair. Synthetic tihers have made inroads into the use of all natural fibers, bul the greatest impact has occurred in connection with the latter three libers. Cotton continues to be a major textile fiber, measured in terms of billions of pounds used per year. Colton is one of the most versalile of all libers and blends well with synthetics. This is also true of wool, bul lo a somewhat lesser extent. Synthetic Fibers. Introduced in 1910 as a substitute for silk, rayon was the first artificial or synthetic fiber. Rayon, of course, differs completely in chemical constitution from silk. Rayon typifies most reconstituted or synthetic fibers, which perform almost as well and. in a number of respects, far better than their natural counterparts Some of the more recently developed synthetic libers have lilile if any resemblance to naturally available fibers and thus enlirely new types of end-producls with previously unobtainable end-qualities are available,... 

Yanagisawa, H., Davis, E. C., Starcher, B. C., Ouchi, T., Yanagisawa, M., Richardson, J. A., and Olson, E. N. (2002). Fibulin-5 is an elastin-binding protein essential for elastic fiber development in vivo. Nature 415, 168-171. 

Herzog was sufficiently impressed that he put Polanyi in charge of a research group that was to develop X-ray diffraction studies of both natural fibers and metals. 

Asbestos fibers occurring naturally in minerals such as serpentine were once valued for their insulating qualities and resistance to chemical attack. Locomotive and industrial boilers, pipes, and cargo compartments of ships were once coated with asbestos. However, there have been so many cases of workers in the asbestos industry developing respiratory illnesses such as asbestosis or mesothelioma that asbestos is no longer being used and in many places it is being removed. 

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