Fibre development

Polylactic acid (PLA) reinforced with kenaf fibres developed by NEC for personal computer housings. With a 20% level of kenaf fibres, the main properties compete with glass fibre reinforced ABS but the cost is 50% higher. The flexural modulus is more than 4.5 GPa and the HDT reaches 120°C. 

Losses still occur in the fibres developed for commercial use. Nonetheless, these have been reduced to a point where transmission over kilometres is possible. Along with transmission of information in telephone systems and similar applications, it has been suggested that optical devices may replace conventional electronics in more advanced applications such as computers. For such applications, it will be necessary to develop optical switches, amplifiers, and so on. In the last two decades, new materials have been developed that may form the basis of integrated optical circuits. These materials are photonic crystals. 

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

Vieira, V.L.A. and Johnston, I.A. (1992). Influence of temperature on muscle-fibre development in larvae of the herring Clupea harengus. Marine Biology 112, 333-341. 

Providing flame retardancy for fibre blends has proved to be a difficult task. Fibre blends, especially blends of natural fibres with synthetic fibres, usually exhibit a flammability that is worse than that of either component alone. Natural fibres develop a great deal of char during pyrolysis, whereas synthetic fibres often melt and drip when heated. This combination of thermal properties in a fabric made from a fibre blend results in a situation where the melted synthetic material is held in the contact with the heat source by the charred natural fibre. The natural fibre char acts as a candle wick for the molten synthetic material, allowing it to bum readily. This can be demonstrated by the LOl values of cotton (18-19), polyester (20-21) and a 50/50 blend of both (LOl 18), indicating ahigher flammability of the blend as described later (Section 8.11). But a rare case of the opposite behaviour is also known (modacrylic fibres with LOl 33 and cotton in blends from 40-60 % can raise the LOl to 35). 

Turner, A. J., Bast and Leaf Fibres—Development and Prospects, 325-38 ... 

The evolution of fibre development has gone through the phases of conventional fibres, highly functional fibres and high-performance fibres. Polyester is the single most common fibre used for sportswear and active wear. Other fibres suitable for active wear are polyamide, polypropylene, acrylics and elastanes. 

The spatial arrangement of elementary fibrils and larger aggregates determines the morphology and properties of a fibre and in maturing cotton the arrangement of these structural units differs, depending on the state of fibre development. 

The cellulose in the secondary wall is laid down in a series of concentric growth rings or lamellae that reflect diurnal temperature fluctuations during fibre development. Lord reported up to 50 lamellae other workers have estimated between 25 and 40 lamellae in a mature fibre. The first rings deposited on the inside of the primary wall are known as the transition lamellae. 

Like the polyhydrazide fibres described in the previous section these oxalyl-containing fibres develop their highest moduli on heat treatment and are capable of a limited amount of drawing. The polyoxamide XII seems to be able to stand the higher treatment temperature. After a pre-drawing at a moderate temperature it increases its modulus almost without drawing when heated to 500° in a way reminiscent of polymers A and B. 

The papermakers always make a trade-off between fibre development and machine speed or throughput. However, the ultimate objective of the paper mills is to produce a paper product that must satisfy the end-users requirements. 

Since the start of papermaking, fibre treatment has been almost a qualitative art form dependent on the skill and artistry of the operator. Fibre development has been described... 

This group is perhaps the most well known and exploited of all the inherently heat and flame resistant fibres developed since 1960 and all members of this group are typified by having thermal resistances in excess of 300 °C for short-term exposures and high levels of inherent flame resistance (see Tables 8.1 and 8.4). Because of their aromatic polymeric structures, they possess quite low H/C ratios <1 (see section 8.2) and so release few potentially flammable volatiles, reflected in their high LOI values of 29 vol% or greater (see Tables 8.1 and 8.4). 

H Struszczyk, J Lebioda, K Twaiowska-Schniidt and A Nidoaszewicz, New Bioactive Syndietic Fibres Developed in The Institute of Chemical Fibres , Fibres and Textiles in Eastern Europe, 2003 11(2) 96-99. 

DIHERENTLY ANTIMICROBIAL ALCHTTE FIBRES DEVELOPED FOR WOUND CARE APPUCATIONS... 

Results showed that different textile properties had an influence on cell attachment and cell growth. FirsUy, the fibre diameter i uenced ceU attachment Finer fibres lead to better cell attachment. Secondly, drawn fibres supported a better cell growth than undrawn fibres with the same diameter. The obtained results suggest that an end-product targeted fibre development leads to an improved implant performance. Specially designed fibres should therefrne be considered in future implant development Further investigation will be carried out using a different cell line to proof the achieved results. 

A. R. Bunsell and M. H. Berger, Ceramic fibre development and characterization, in Key Engineering Materials, Vols. 127-131 15-26, Trans. Tech. Publ., Switzerland (1997). 

Logsdail DH, Aspects of carbon fibre development at AERE, Harwell, Preston J ed.. High temperature Resistant Fibers from Organic Polymers, Interscience, New York, 245, 1969. 

This group is perhaps the best known and exploited of all the inherently heat and flame resistant fibres developed since 1960, and all members of this group are typified by having thermal resistances in excess of 300°C for short-term exposures and high levels of inherent flame resistance (see Table 4.2). 

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