Types of fibre

Fig. 3.4 Stress-strain behaviour for several types of fibre reinforcement...

In our laboratory this kind of research has been systematically carried out for a number of years. A certain progress has been made in developing new promising methods for the chemical modification of PAN and acrylonitrile (AN) copolymers, and in creating new types of fibres with technologically valuable properties. 

The pulp industry is broken down into predominantly two types of fibre types ... 

The Ap fibres are examples of afferents that stimulate inhibitory interneurones (in the substantia gelatinosa (SG)) and, therefore, prevent nociceptive transmission to the CNS. The C fibres are examples of afferents that inhibit inhibitory interneurones and, therefore, enhance nociceptive transmission. Note that both types of fibre stimulate the second-order neurone (2°) directly but it is the intemeurone that modifies the transmission. 

In hybrid reinforcement, two or more types of fibres are used in the same composite. 

The reinforcement obtained with a given level of a given type of fibres is a function of the length, the aspect ratio and the orientation of the fibres. 

Metallisation of fibres is not only a physical process determined by absorption capacity of the fibres for the metal and diffusion capacity of the metal in the fibre structure, but also depends on chemical parameters such as chemical structure of the fibres, presence of functional groups, reactivity of the fibre and the metal, oxidation state of the metal and the presence, necessity and reactivity of supporting chemicals (e.g. reducing agent). Therefore, it was necessary first to study metallisation at different types of fibres in order to investigate which structure is most useful for further research. In this respect, viscose, cotton, natural silk and polyacrylonitrile fibres were investigated because of their different structure and properties and their availability in the New Independent States of the former Soviet Union (Uzbekistan, Kazakhstan, Kyrgyzstan). 

Table 7 7.7 Nickel absorption and reduction by sodium dithionite and rongalite for different types of fibres and their electroconductive capacity...

Various types of oxide fibres available commercially can be considered as suitable reinforcements other than the types of fibres listed in Table 3.2 ... 

Zeronian, S. H., Alger, K. W., Ellison, M. S., and Al-Khayatt, S. M. (1986). Studying the cause and type of fibre damage in textile materials by scanning electron microscopy, in Historic Textile and Paper Materials, Conservation and Characterisation, vol. 212 (H. L. Needles and S. H. Zeronian, Eds.). Washington, DC American Chemical Society, 77-94. 

The fibre characteristics depend on the source. Table 5.2 gathers the main characteristics of industrial vegetable fibres. A short description of every type of fibre and their applications are given in the following paragraphs. 

Q7 Fibre comes from the parts of plants which cannot be digested in the human gut. It may either be insoluble, for example cellulose, hemicellulose or lignins, or the soluble type, such as pectins and gums. The soluble type of fibre helps to slow absorption of cholesterol from the gut, lowers blood cholesterol and decreases the risk of coronary disease. 

Kind of fibres Type of fibre, hydrophilic or hydrophobic, smooth or porous fibre surface... 

Table 8.5 Limiting oxygen index (LOI) values of different types of fibres...

As the oxygen content of air is 20 % corresponding to LOI = 20 all textiles with lower LOI values will bum quite easily in air and those with LOI values much higher than 20 will not bnm. Table 8.5 illustrates this readily imaginable measure for the flammability and bnmability of different types of fibres. 

It is the aqueous dispersion of a fatty acid salt and it is resistant to metal salts. It can be used for all types of fibre, but is recommended mainly for cellulosic textiles. 

In this paper, all the blends and composites are designated by the type of matrix (G for the neat nylon, D for the 8 wt % rubber-modified nylon and N for the 20 wt % rubber-modified nylon), the concentration of fibres and the type of fibre/matrix interface (A or B). As an example, a material designed DlOB is a ternary blend made of DZ matrix and 10 wt% of type B fibres. After drying the specimens for 24 hours at 100°C, they were stored in plastic bags inside a desiccator. In comparison with freshly injection moulded samples, the moisture content in the specimens ready for mechanical testing is about 2 wt%. All the mechanical tests were conducted in an environmental chamber in controlled conditions a temperature of 20°C under a continuous argon flow. 

A coated fused silica fibre is directly introduced in the liquid sample or in the headspace above the sample. Respective ingredients from the sample material are absorbed onto the fibre material until equilibrium is reached. The fibre is removed from the sample and directly applied into the injection system of the GC. The absorbed compounds are thermally desorbed into the GC column for analysis. The method is solvent-free and requires no special additional equipment. It is used for the analysis of special groups of compounds, depending on the enrichment based on the type of fibre used/52-567. 

The nature of textile effluents is very complex as various types of fibres and chemicals are employed in preparing the textiles. Further the process sequence and chemicals employed in the pre-treatment processes vary from fibre to fibre. The quantities of pollutants that form the pollution load going into the waste water thus depend on the amount and kinds of fibres, type of manufacturing operation employed and water consumption practices. 

Table 8.5 Suitability of IR bands for identifying silicone stains, depending on the type of fibre ...

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