Paper surface treatments

Filiform corrosion is characterised by the formation of a network of threadlike filaments of corrosion products on the surface of a metal coated with a transparent lacquer or a paint him, as a result of exposure to a humid atmosphere. This phenomenon first attracted attention because of its formation on lacquered steel, and for this reason it is sometimes referred to as underfilm corrosion, but although it is most readily observed under a transparent lacquer it can also occur under an opaque paint film or on a bare metal surface. Filiform corrosion has been observed on steel, zinc, magnesium and aluminium coated with lacquers and paints, and with aluminium foil coated with paper. Surface treatment of the metal by phosphating or chromating lessens the tendency for filiform corrosion to occur, but it is not completely... 

Incorporated in plasticized PVC, P.B.15, like other phthalocyanine pigments, is usually entirely fast to migration. Moreover, it provides excellent lightfastness. P.B.15 also finds use in various types of PUR foam materials as well as in rubber. Its redder and frequently cleaner shade compared to corresponding stabilized types makes it an equally useful pigment for other media. This applies especially for water-based systems. Textile printing, paper mass coloration, paper surface treatment, and paper pulp are areas of application as suitable for the use of P.B.15 as office articles, including colored pencils, blackboard chalks for schools, and water colors. 

In addition, colloids can be added in paper surface treatments, such as surface sizing or coating. In coating, often, mixtures of pigments and binders [e.g. polystyrene butadiene (PSB) latex] are used, together with polymers, such as rheology modifiers, which can also lead to flocculation. Clearly, from these examples. 

D. Hawke and K. Gaw, "Effects of Chemical Surface Treatments on the Performance of an Automotive Paint System on Die Cast Magnesium," Paper 920074, Society of Automotive Engineers International Congress and Exposition, Detroit, Mich., 1992. 

Curl Control. Many grades of paper tend to cud, especially as humidity varies, because of the stresses produced duting the dryiag process. This is especially troublesome when only one side of the paper receives a surface treatment. Judicious appHcation of water to the opposite side of the dry sheet followed by redryiag may correct the curling. Water may be appHed by surface appHcation at the size press, water box, or calender stack or it may be sprayed on. Small amounts of water can be appHed to the paper surface as a foam with exceUent results. 

Other plant-scale applications to pollution control include the flotation of suspended sewage particles by depressurizing so as to release dissolved air [Jenkins, Scherfig, and Eckhoff, Applications of Adsorptive Bubble Separation Techniques to Wastewater Treatment, in Lemlich (ed.). Adsorptive Bubble Separation Techniques, Academic, New York, 1972, chap. 14 and Richter, Internat. Chem. Eng, 16,614 (1976)]. Dissolved-air flotation is also employed in treating waste-water from pulp and paper mills [Coertze, Prog. Water TechnoL, 10, 449(1978) and Severeid, TAPPl 62(2), 61, 1979]. In addition, there is the flotation, with electrolytically released bubbles [Chambers and Cottrell, Chem. Eng, 83(16), 95 (1976)], of oily iron dust [Ellwood, Chem. Eng, 75(16), 82 (1968)] and of a variety of wastes from surface-treatment processes at the maintenance and overhaul base of an airline [Roth and Ferguson, Desalination, 23, 49 (1977)]. 

Dry end operations drying of paper product, application of surface treatments, and spooling for storage... 

Valuable results with Tof-SIMS imaging have been obtained e.g., with paper samples. The distribution of papermaking chemicals on the surface of coated and uncoated papers is very important for its further treatment, such as printing. Figure 16 [70] is an example of use of the technique for chemical microscopy analysis of paper surfaces. 

If the fibres in the paper have been rendered hydrophobic by sizing, but the sheet has an open structure and there has been no surface treatment to cover the sized fibres, then the web will show a high contact angle. However, if the same web is tested by a penetration-type test, the sizing level will be low. 

The main nutrients which are present in a paper mill effluent are carbohydrates from wood pulp or from waste paper, and also products which arise from their degradation. Compositions may be very variable and depend to a large extent upon the type and amount of waste paper, if any, which is being used. Recycled coated and surface-sized papers will introduce significant amounts of soluble polymers, in particular starch, which were used in the original surface treatment. 

Pipes for paper and surface treatment sectors, electroplating plants, photographic, semiconductor and chemical industries. .. 

Acid cleaners based on sulfamic acid are used in a large variety of applications, eg, air-conditioning systems marine equipment, including salt water stills wells (water, oil, and gas) household equipment, eg, copper-ware, steam irons, humidifiers, dishwashers, toilet bowls, and brick and other masonry tartar removal of false teeth (50) dairy equipment, eg, pasteurizers, evaporators, preheaters, and storage tanks industrial boilers, condensers, heat exchangers, and preheaters food-processing equipment brewery equipment (see Beer) sugar evaporators and paper-mill equipment (see also Evaporation Metal surface treatments Pulp). 

Perfluoroalkyl compounds have been manufactured since the 1950s.The total production of fluorinated surfactants (anionic, cationic and neutral) was 2001 in 1979, whereas in 2000 the total production of PFOS (perfluorooctane sulfonate) alone was nearly 3000t (Shoeib et al., 2004). Together with PFOA (perfluoroocta-noic acid), PFOS is used in refrigerants, surfactants, fire retardants, stain-resistant coatings for fabrics, carpets and paper and insecticides. Surface treatments, such as protection of clothing and carpets constitute the largest volume of PFOS production (Moriwaki, Takata and Arakawa, 2003). PFOA as well is present in several... 

Surface treatment of textiles, leather, glass, wood, and paper is the second largest application for fluorinated polyurethanes. The coatings are applied in one-step treatment and impart resistance to soil, water, oil, and stains as well as a smoothness to fabrics and leather that resists removal by many cycles of laundering or dry cleaning.52... 

Paper Industry Surface treatment during manufacture of water repellent papers and cardboards... 

Provided in this chapter is an overview on the fundamentals of polymer nanocomposites, including structure, properties, and surface treatment of the nanoadditives, design of the modifiers, modification of the nanoadditives and structure of modified nanoadditives, synthesis and struc-ture/morphology of the polymer nanocomposites, and the effect of nanoadditives on thermal and fire performance of the matrix polymers and mechanism. Trends for the study of polymer nanocomposites are also provided. This covers all kinds of inorganic nanoadditives, but the primary focus is on clays (particularly on the silicate clays and the layered double hydroxides) and carbon nanotubes. The reader who needs to have more detailed information and/or a better picture about nanoadditives and their influence on the matrix polymers, particularly on the thermal and fire performance, may peruse some key reviews, books, and papers in this area, which are listed at the end of the chapter. 

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