Separation of fibres

Paper is made from a suspension of fibres in water. The suspension is drained through a fine mesh so the water drains away and the fibres are retained to form a mat on the mesh. On drying, the fibres stick together and form a sheet of paper. Many paper experts define paper as a material made by a process that involves the separation of fibres into a suspension with subsequent formation into a sheet. 

The basic principles used here are not new, of course horizontal units of this type have been used for many years in the paper-making industry, fit the latter, however, the filtered material is highly porous and constitutes a small resistance to filtration and dewatering processes. It follows that the hi -speed paper machine requires only a small pressure diflferential for the separation of fibres. 

Both thermoplastics and thermosets can reap the benefit of fibre reinforcement although they have developed in separate market sectors. This situation has arisen due to fundamental differences in the nature of the two classes of materials, both in terms of properties and processing characteristics. 

Disclosed is a process for recovering monomeric units of a nylon from whole carpet composed of fibres of the nylon and a backing composed of non-nylon components, the fibres being bound to the backing and the carpet containing between 15 and 35 wt.% of the nylon. It involves the steps of a) mechanically separating the whole carpet into a carpet mixture, which contains between 35 and 55 wt.% of nylon, and a depleted carpet mixture, and exposing the carpet mixture to conditions under which depolymerisation of the nylon is effected. 

Kcurentjes et al. (1996) have also reported the separation of racemic mixtures. Two liquids are made oppositely chiral by the addition of R- or S-enantiomers of a chiral selector, respectively. These liquids are miscible, but are kept separated by a non-miscible liquid contained in a porous membrane. These authors have used different types of hollow-fibre modules and optimization of shell-side flow distribution was carried out. The liquid membrane should be permeable to the enantiomers to be separated but non-permeable to the chiral selector molecules. Separation of racemic mixtures like norephedrine, ephedrine, phenyl glycine, salbutanol, etc. was attempted and both enantiomers of 99.3 to 99.8% purity were realized. 

Fig. 4.4(a) Development of the N. terminalis in mammals and relationship to Vomeronasalis system (i) f = filia olfactoria (ii) induction of olfactory bulb and (iii) to (iv) separation of main/accessory systems (v,o) — from t, Nt system g, Nt ganglion + p/c, peripheral and t, central fibres (from Oelschlaeger, 1989). 

In determination of health hazards due to exposure to fibre inhalation, the feasibility of using the inertial spectrometer (INSPEC) as a sampler that separates fibres according to their aerodynamic diameter was explored. Optical and electron microscopy demonstrated a satisfactory size separation of the fibres and alignment along the flow lines. 16 refs. 

In this section we will present some modelling developments for various forms of composites. The purpose is not to propose a calculation method - excellent computer software programs exist for that - but to show the broad strength range according to the composite structure, to underline the separate effects of fibres and matrix, and to examine the effects of some service conditions. These examples cannot be used for design calculations. 

Separation of EMCL and IMCL in proton muscle spectra is possible due to the different geometrical arrangement of these lipid compartments resulting in different bulk magnetic susceptibility (BMS). EMCL are nestled in long fatty septa along the muscle fibre bundles or fasciae, and can thus be described in a simplified way as coaxial cylinders. IMCL are located in a roughly spherical... 

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