Fibre continued structure

Ceramic oxide fibres, both continuous and discontinuous, have been commercially available since the 1970s, and processing and microstructure control are very important in obtaining the desired properties. Among the desirable characteristics in any ceramic fibre for structural applications are ... 

Y. Hasegawa, Synthesis of continuous silicon carbide fibre. Part 6 Pyrolysis process of cured polycarbosilane fibre and structure of SiC fibre, J. Mater. Sci., 24,1177-90 (1989). 

Natural fibres can be obtained from various parts of a plant, as shown in Table 13.2. Natural fibres can be continuous fibres, short fibres, whiskers or particles, as shown in Figure 13.4. Types of polymer composite based on shape and structure are divided into particle, fibre and structural. 

Steel fibres continue to have a wide range of apphcations in civil engineering materials. There are some structural applications where they have been used in concrete without any conventional reinforcing bars. These have been short span, elevated slabs, for example a parking garage at Heathrow Airport... 

The glass transition temperature of polyamide fibres continues to evoke interest with a paper on the effect of molecular structure, water, fibre structure and experimental technique on this property which was related to dyeability. ... 

Nonwovens are structures of textile materials, such as fibres, continuous filaments, or chopped yarns of any nature or origin, that have been formed into webs by any means, and bonded together by any means, excluding the interlacing of yams as in woven fabric, knitted fabric, laces, braided fabric or tufted fabric. 

Dietary fibre, which comprises all the non-digestible structural carbohydrates of plant cell walls and any associate lignin, provides a further example of a complex food-borne factor which cannot be classified as a nutrient, and which continues to generate debate over such issues as definition and analytical techniques. However, whatever the unresolved complexities, dietary fibre has a lengthy history and had proved itself eminently suitable as a component of functional food products long before the term was even coined. 

The nature of the nitrocellulose used is of particular importance in explosives if freedom from exudation of free nitroglycerine during storage is to be avoided. Nitroglycerine is only a poor solvent for nitrocellulose and stability of the gel depends on continuous formation and breakdown of gelled structures. The distribution of nitrogen content and viscosity, even in the individual fibres of the nitrocellulose, is therefore of paramount importance. 

In view of the development of the continuous chain model for the tensile deformation of polymer fibres, we consider the assumptions on which the Coleman model is based as too simple. For example, we have shown that the resolved shear stress governs the tensile deformation of the fibre, and that the initial orientation distribution of the chains is the most important structural characteristic determining the tensile extension below the glass transition temperature. These elements have to be incorporated in a new model. 

These are defined as anionic dyes with substantivity for cellulosic fibres applied from an aqueous dyebath containing an electrolyte. The forces that operate between a direct dye and cellulose include hydrogen bonding, dipolar forces and non-specific hydrophobic interaction, depending on the chemical structure and polarity of the dye. Apparently multiple attachments are important, since linearity and coplanarity of molecular structure seem to be desirable features (section 3.2.1). The sorption process is reversible and numerous attempts have been made to minimise desorption by suitable aftertreatments (section 10.9.5). The two most significant non-textile outlets for direct dyes are the batchwise dyeing of leather and the continuous coloration of paper. 

The structure of PBT fibres, has not been completely resolved although efforts are continuing using diffraction analysis, For example Adams et al. 95) have interpreted the x-ray diffraction patterns of oriented PBT fibres in terms of a nematic arrangement of molecules which are treated as periodic cylinders packed in an hexagonal array. The cylinders are oriented parallel to each other but are arbitrarily displaced axially. Unfortunately although the model explains many features of the diffraction pattern it predicts a fibre density which is well below the observed experimental value. 

The continuous monitoring of can be obtained by using a fibre optic cable attached to the pipe itself or to the structural elements connected to the pipe. The fibre can act as a simple data transmitter (insensitive fibre) or be itself a sensor for its total length or for only selected sector (sensitive fibre). The different possibilities are presented in Figure 4. 

The heating process is continued at 400-600 °C and then at 600-1300 °C and the chains as shown in figure 14.6 grow together to form the ultimate fibre with a graphite structure and N atoms on the... 

Galvanisation of the metallised fibre will improve its properties as electrical conductor because of the formation of a continuous metallic coating at the surface of the fibre. In this respect, the seed layer formed during metallisation is crucial for a good adhesion between the metal layer and the PAN-fibre structure. 

Reinforcements in the form of continuous fibres, short fibres, whiskers or particles are available commercially. Continuous ceramic fibres are very attractive as reinforcements in high-temperature structural materials. They provide high strength and elastic modulus with high temperature-resistant capability and are free from environmental attack. Ceramic reinforcement materials are divided into oxide and non-oxide categories, listed in Table 3.1. The chemical compositions of some commercially available oxide and non-oxide reinforcements are given in Table 3.2 and Table 3.3. 

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