Coatings process availability

In spite of the relatively poor tensile strengths of the fibers, carbonized Kevlar possesses characteristics that make it an ideal candidate as a substrate for chemical vapor deposition of silicon carbide including a compatible coefficient of thermal expansion, sufficient tensile strength to survive the coating process, availability from a reliable domestic supplier, and a smooth, even diameter of less than 7 fim (78). 

Almost all PVC powder coatings are appHed by the fluidized-bed coating process. Although some electrostatic spray-grade formulations are available, they are very erratic in their appHcation characteristics. The resistivity of plasticized PVC powders is low compared to other powder coating materials and the appHed powder quickly loses its electrostatic charge. For the same reason, PVC powders show poor appHcation characteristics in an electrostatic fluidized bed and are seldom used in this process. 

Fig. 10 Example of a contact-killing and microbe-releasing surface. The scheme shows the design of a two-level dual-functional antibacterial coating containing both quarternary ammonium salts and silver. The coating process begins with LbL deposition of a reservoir made of bilayers of PAH and PAA. (A) Cap region made of bilayers of PAH and SiC>2 nanoparticles (NP) is added to the top. (B) The SiC>2 nanoparticle cap is modified with a quarternary ammonium silane (QAS) PEM polyelectrolyte multilayer. (C) Ag+ is loaded into the coating using the available unreacted carboxylic acid groups in the LbL multilayers. Scheme was reproduced from [138]...

Coat commercially available supports with developed intermediate layer and test them under process conditions. 

Maintenance difficulties encountered with floors and roofs should be given particular attention in a structural design. Concrete floors are used extensively in the process industries, and special cements and coatings are available which make the floors resistant to heat or chemical attack. Flat roofs are often specified for industrial structures. Felt saturated with coal-tar pitch combined with a coal-tar pitch-gravel finish is satisfactory for roofs of this type. Asphalt-saturated felt may be used if the roof has a slope of more than jin./ft (4.17 cm/m). 

The main advantage of this approach is that solvent emission (e ept tiiat from the coating solution) is diminated. In addition, the printed films show high gloss and good abrasion resistance. Moreover, paper printed by this process can be recycled without complication, and both alcohol-based and water-based coatings are available. 

Aluminium aerosols are inherently more expensive than tinplate but can be made in one piece with neither side seam nor bottom chime. However, for practical or economic reasons these Monobloc containers are usually restricted to the smaller sizes of aerosol. Larger sizes are produced in two pieces, i.e. with a continuous side wall and a seamed-on base. In the past few years the process of drawing and wall ironing has enabled continuous side wall containers to be produced from both aluminium and tinplate sheet. Unlike two-piece extruded body containers, these containers have no base chime but instead have a seamed-on cone. When two different metals are involved, e.g. aluminium body and tinplate base, additional product compatibility checks must be carried out due to the risk of electrolytic corrosion. Again special coatings are available to inhibit this effect. 

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