Coatings continued decorative

Coatings continue to be used at an unprecedented rate for both decoration and protection. Over 1 billion gallons of coatings are produced annually in the United States at a selling price of 10 billion. 

Lay-up proceeds by laying down the veneer which is to be the back surface of the panel. Then a sufficient number of pieces of core veneer are passed through the glue spreader to form the next layer of cross-oriented veneer. The glue spreader commonly used in hardwood plywood manufacture is a roU coater in which a pair of opposing mbber roUs are coated with a thin layer of adhesive. As the veneer is passed between the roUs, the adhesive is transferred to the surfaces of the veneer. Adhesive is appHed only to the cross-pfles and in sufficient quantity to provide a continuous layer on both opposing faces of veneer. Thus, in the case of a three-ply panel, only the core layer is spread with adhesive and in that of a five-ply panel, the second and fourth layers both of which are cross-pfles, are spread with adhesive. Then the top surface veneer, which is normally the decorative surface, is placed on the assembly. 

Fig. 5.16 (a) (i) Schematic of the electrochemical coating of SWCNT connected cathode from a sacrificial silver cathode with SEM images (ii) before and (iii) after Ag NP decoration, (b) Examples of fractal patterns possible with continued deposition, arrows indicate original position of SWCNT. Scale bar in all SEM images represent 1 pm. Altered and reproduced with permission from [217],... 

PROTECTIVE COATING. A film or thin layer of metal glass of paint applied to a substrate primarily to inhibit corrosion, and secondarily for decorative purposes, Metals such as nickel, chromium, copper, and tin are electrodeposited on the base metal paints may be sprayed or brushed on. Vitreous enamel coatings are also used these require baking. Zinc coating are applied by continuous bath process in which a strip of ferrous metal is passed through molten zinc. 

For applications such as cladding fire-rated bulkheads and doors in ships and other vessels decor papers have been bonded directly to thin steel sheet. However, for these purposes steel coated with PVC and thin continuous laminate bonded to steel now are used more commonly. 

The sap of a shrubby tree growing over large areas of Asia has been used to produce a highly durable protective and decorative coating for a wide variety of objects. The finished material, called lacquer, is known to have been used for over 3700 years. It is seen on utilitarian everyday objects such as boxes, trays, and cups, and further serves as a protective and decorative coating on furniture, armor, masks, and sculpture. Furthermore, lacquer ware continues to be used and remains highly prized even today. 

Coatings can form naturally by reaction with the surrounding atmosphere aluminum is quickly covered by an aluminum oxide and hydroxide layer in the presence of oxygen and water. This inert and protective layer can be formed artificially, as is done for window and door frames. A porous layer of alumina can be formed by reaction with oxygen. Pigments can be included in the pores for decorative purposes. After inclusion of the pigments, a suitable treatment of the layer transforms its porous structure to a continuous nonporous one (sealing). These coated frames can withstand relatively harsh conditions for years. 

As pointed out earlier, there m a legion of applications for metallized plastics, ranging from the very mundane (e.g., as decorative coatings) to high tech (in microelectronics). Even a cursory look at the current literature will evince that the topic of metallized places is pursued with very keen interest, and all signals indicate that this high tempo of interest and R D activity will continue unabated. 

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