Method coating

In the paste coating method, a PVC paste, which contains emulsion-polymerized PVC and additives, is appHed onto a substrate and heated to gelation before fusion to produce a coating layer. This method is employed for products with a thin layer, ie, of 0.007—0.05 mm thickness. For foamed vinyl-coated fabrics, a substrate is laminated onto a transfer paper on which a PVC paste containing a foam-blowing agent has been appHed and geUed. After removal of the transfer paper, the paste is blown. 

Numerous schemes can be devised to classify deposition processes. The scheme used herein is based on the dimensions of the depositing species, ie, atoms and molecules, softened particles, Hquid droplets, bulk quantities, or the use of a surface-modification process (1,2). Coating methods are as foHow (2) ... 

Coating method Advantages Limitations Typical uses... 

Advantages of the hydrosilation system (Fig. 3) include the elimination of solvent, improved cure speed, and potential for UV or thermal cure. Drawbacks to the system include more expensive multiroll coating methods, potential poisoning of the Pt catalyst (with Sn, S, Cr, amines, etc.), poor anchorage to some films, and a need to carefully balance the hydride to vinyl ratio employed for cure to avoid detrimental interactions with acid containing adhesives [23,53]. 

The methods of protection available are of two basic kinds chemical or electrochemical treatments which oxidise the metal and produce a film which is more stable than the metal itself, and coating methods which rely... 

The more important metallic coating methods such as electroplating, spraying, hot-dipping and diffusion have already been considered. There are, however, several other methods which have certain advantageous features and therefore find exclusive application in specific fields. These include new techniques such as laser hardening and alloying. ... 

Properties of deposits Deposits are often more adherent, coherent and temperature-stable than those produced by alternative coating methods. Adhesion can be adversely affected by spurious reactions between the metal-gas and impurities in (e.g. as observed during the deposition of molybdenum on steel ) and also where the thermal coefficients of expansion of A/, and differ widely. The purity of reactants can affect that of A/,. crystal size is reduced by raising the reactant concentrations, or by lowering the plating temperature. 

Electrophoretic and similar compacted coatings are in early stages of development but will no doubt take their place alongside other coating methods. 

Each coating method has its own particular advantages, which are really the decisive factors in determining which one is used for a given purpose. Consideration must be given to the complexity and size of the work, the corrosion resistance, and hence the coating thickness needed, and the quality of finish required. 

Miscellaneous powder coating methods Apart from the coating techniques described briefly above, the jobbing or custom coater has a whole armoury of other methods which are more or less related to those described above. 

Specification for electroplated coatings of 65/35 tin/nickel alloy Method for the evaluation of results of accelerated corrosion tests on metallic coatings Methods of test for paints Cross-cut test Pull-off test for adhesion Resistance to artificial weathering (enclosed carbon arc) and Addendum No. 1 Resistance to continuous salt spray Notes for guidance on the conduct of natural weathering test... 

Paraffin Coating Method for the Removal of Gunshot Residues from Hands... 

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