Fibrous surfaces

Extractives sometimes prevent or inhibit the utilization of wood. For example, woods containing phenolic type extractives cannot be pulped via the sulfite process. The so-called "pitch troubles" in the pulp and paper industry result from the tendency of the resin type extractives to coagulate and adhere to metal and fibrous surfaces. Also the presence of extractives result in a higher consumption of pulping chemicals and in lower pulp yields. 

Fig. 34. Relict organic structures in Precambrian cherty iron-formations (after La Berge). I = type A structure, well preserved due to carbonaceous matter in chert matrix note fibrous surface and clear interior (lower chert unit of Biwabik Iron Formation, Pilotac mine, Minnesota) 2 = type A structure, largely replaced by greenalite 3 = type A structure, preserved due to unidentified brown substance (hematite ) in chert matrix (Belcher Islands iron-formation) 4 = type B structure (Eosphaera tyleri), well preserved due to carbonaceous matter in chert matrix (Gunflint district) 5 = type B structure in which most of the organic matter has been replaced by extremely fine hematite (Vicar mine, Gogebic district) ...

Water-soluble soil (sodium chloride, sugar) appears to be removed by solubilization (Chapter 4, Section II) into free water in the interior of surfactant micelles in the solvent. Surfactant micelles in nonpolar solvents are formed with the polar heads oriented into the interior of the micelle. Water is added to the dry-cleaning solvent and is solubilized into the interior of these micelles. Some of this water in the interior is bound strongly to the polar heads of the surfactants in the interior of the micelle and some is essentially free water. Studies (Aebi, 1959) have shown that it is the free water that dissolves water-soluble soil rather than the bound water. In the absence of any free water in the solvent, water-soluble soil is not removed to any significant extent. The water-soluble soil appears to be removed from fibrous surfaces by a process involving hydration of the soil followed by solubilization (Monch, 1960 Rieker, 1973). 

The addition of PEO has an influence on film destruction caused by an external destructive force (Figure 7). Without PEO, the external force created a clear-cut fracture surface, indicating the good adhesion between the two biopolymers. With the inclusion of PEO, the deformation created a fibrous surface. This can be seen more clearly from SEM and fluorescent microscopy. As shown in Figure 8 A and B, fibers were pulled out, extended, and then, broken, but still embedded in the matrix phase. We examine the fibers with confocal reflection and confocal fluorescence in two channels. It confirms that the main component of the fibers is PEO however, the biopolymers were either inserted or encapsulated within the fibers (Figure 8C). 

Olsen A, Wick MJ, Morgelin M, Bjorck L (1998) Curfi, fibrous surface proteins of Escherichia coli, interact with major histocompatibility complex class I molecules. Infect Immun 66 944-949... 

The modification of polymers and fibrous surfaces to alter the porosity, wettability and other characteristics of polymeric substrates, will enable the prodnction of implants and biomedical devices which exhibit greater resistance to microbial adhesion and biofilm formation. A nnmber of polymers have been developed that can be incorporated into cellulose and other materials, which will provide significant advances in many fields snch as food packaging, textiles, wound dressings, coating of catheter tnbes and sterile surfaces. 

Whilst the singeing process is designed to denude the fabric of its protruding fibres, the raising process is designed actually to create a fibrous surface, normally on the outlet side of the filter sleeve, to enhance the fabric s dust collection capability. It follows therefore that this process is designed essentially for woven fabrics comprising... 

Fabrics produced from short staple fibres have a natural fibrous surface (an example can be seen in Figure 2.4) that can impede cake discharge this is overcome by singeing the fabric by passing it over a gas flame or a hot metal strip, which is usually followed by contact with a wet surface in order to stop any smouldering. 

The recent review by Cunha and Gandini can be consulted on rendering polysaccharides hydrophobic [7]. Paper, paperboard and linerboard are the common packaging materials with reasonable mechanical properties, flexibility and low cost. In many packaging applications paper based materials must resist water. The control of wetting of fibrous surfaces with liquids is important for a number of applications such as filtration... 

The mechanism of grafting polymer to fibrous surfaces is usually considered (7-12) to involve primary radical attack on substrate, terminating initiator activity, with simultaneous formation of an active center on the substrate that initiates a grafted chain. A rate law, involving assumption of homogeneous reaction kinetics, has been suggested (2)... 

Solvent bonding is suitable for all amorphous plastics. It is used primarily on ABS, acrylics, cellulosics, polycarbonates, polystyrene, polyphenylene oxide, and vinyls. Solvent welding is not suitable for crystalline thermoplastics. It is not effective on polyolefins, fluorocarbons, or other solvent-resistant polymers. Solvent welding is moderately effective on nylon and acetal polymers. Solvent welding cannot be used to bond thermosets. It can be used to bond soluble plastics to unlike porous surfaces, including wood and paper, through impregnation and encapsulation of the fibrous surface. 

Removal of asbestos cement sheets causes problems because of their potential height and fragility, and weathering which produces fibrous surface dust. Basic principles to follow are ... 

Fixation or attachment of microbes to polymers and fibrous surfaces and their viability (or persistence) after attachment to the surface have recently received increased attention. Their attachment and persistence are well-recognized in the mechanisms for microbial growth and transmission of disease. Exploratory studies in the early 1920 s... 

An example of polymeric encapsulation of cellulosic fibers during copolymer formation is shown in Figure 23. In this case, the selective introduction on the fibrous surface of reactive epoxy groups influences the application of direct, acid and basic dyes to cotton fabrics. - ... 

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