Painted Surfaces

Solvent cleaning —Immerse, spray, or wipe in either of the solutions given in Tables 7.18 and 7.19, which degrease the surface and leave a dull finish to the paint 

Scrub surfaces with an alkaline cleaner, such as a solution of 2—4% by weight of trisodium phosphate in hot water. Rinse with clean water 

Thermoplastics, thermosets, and elastomers require surface treatment to remove contamination and prepare their surfaces for adhesion bonding. Both initial bond strength and bond durability are affected by the surface preparation technique. Most materials require unique methods of treatment for optimal bond strength formation. Most surface preparation treatment methods use or generate chemicals that have various serious health effects and must be used with extreme caution. 

Petrie EM. Plastics and elastomers as adhesives. In Harper CA, ed. Handbook of Plastics and Elastomers. New York McGraw-Hill 1975. 

Mathieson 1, Bradley RH. Improved adhesion to polymers by UV/ozone surface oxidation. Int J Adhes Adhes. 1996 16 29-31. 

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Application Methods and Surface Preparation. Eor good durabiHty and performance, proper surface preparation and correct appHcation of house paints are as important as the formulation of high quaHty paint. Proper surface preparation prior to painting involves several considerations. Eor new constmction, proper installation and protection of the substrate material are necessary. Eor previously painted surfaces, preparation involves mostly cleaning and removing any existing paint that is unstable. Once surface preparation is complete, the appHcation process can begin. 

Synthetic latex house paints sometimes contain emulsified long oil or very long oil drying alkyds to improve adhesion to chalky painted surfaces. 

When the spectral characteristics of the source itself are of primary interest, dispersive or ftir spectrometers are readily adapted to emission spectroscopy. Commercial instmments usually have a port that can accept an input beam without disturbing the usual source optics. Infrared emission spectroscopy at ambient or only moderately elevated temperatures has the advantage that no sample preparation is necessary. It is particularly appHcable to opaque and highly scattering samples, anodized and painted surfaces, polymer films, and atmospheric species (135). The interferometric... 

Pa.ints, Paints (qv) prepared from poly(vinyl acetate) and its copolymers form flexible, durable films with good adhesion to clean surfaces, including wood, plaster, concrete, stone, brick, cinder blocks, asbestos board, asphalt, tar paper, wahboards, aluminum, and galvani2ed iron (147). Adherence is also good on painted surfaces if the surfaces are free from dirt, grease, and mst. Developments in emulsion polymeri2ation for paint latices have been reviewed (148). 

C select heart C select, choice contains slight defects use for painted surfaces... 

Trisodium phosphate [7601-54-9] trisodium orthophosphate, Na PO, is an important constituent of hard-surface cleaners including those for ceramic, metal, or painted surfaces. It may be used with soaps, surfactants, or other alkaHes. It precipitates many heavy-metal ions but does not sequester to form soluble chelates. It is thus a precipitant builder and additionally an alkaH. 

Painting. A thorough surface treatment of the sheet-metal and a good painted surface are prerequisites for equipment to provide long years of operation. For the benefit of those in the field of manufacturing of such assemblies, we have provided a brief procedure for the sheet treatment and surface painting of these assemblies in the Appendix. 

Painting of all metallic surfaces of a switchgear or a controlgear assembly is an essential requirement to provide it with an aesthetic appearance, on the one hand, and to prevent it from rust and corrosion, on the other. Painting serves these purposes by providing the machine with a hard and longer-lasting metallic surface. We describe briefly, the basic procedure to paint and test painted surfaces. In the discussion, we have laid more emphasis on MS sheet-metal surfaces as these are more typical. 

Whenever a second coat of paint is required for better adhesion of paint, it is better to rub the painted surface of the first coat w ith i finer emery paper... 

Ventilation The paint shop must be well ventilated and provided with exhaust fans to circulate fresh air within the shop. Roughly 20 to 30 air discharges per hour are considered adequate. Wet-painted surfaces, however, must be protected from suspended dust particles in the atmosphere and this can be done by... 

Paints are designed to decorate and protect surfaces. During normal wear, paint chalks moderately to clean the surface continuously. A hardened paint surface resists sorption by gases, although the presence of relatively high concentrations of 2620 to 5240 SO2 (1-2 ppm) increases the drying... 

Airborne contaminant movement in the building depends upon the type of heat and contaminant sources, which can be classified as (1) buoyant (e.g., heat) sources, (2) nonbuoyant (diffusion) sources, and (d) dynamic sources.- With the first type of sources, contaminants move in the space primarily due to the heat energy as buoyant plumes over the heated surfaces. The second type of sources is characterized by cimtaminant diffusion in the room in all directions due to the concentration gradient in all directions (e.g., in the case of emission from painted surfaces). The emission rare in this case is significantly affected by the intensity of the ambient air turbulence and air velocity, dhe third type of sources is characterized by contaminant movement in the space with an air jet (e.g., linear jet over the tank with a push-pull ventilation), or particle flow (e.g., from a grinding wheel). In some cases, the above factors influencing contaminant distribution in the room are combined. 

The mechanical coatings are primarily barrel processed on to parts up to about 150 mm long or 400 g mass. Adhesive bonding (with a conductive adhesive to maintain the electrochemical protection by zinc) is particularly suitable for wrapping pipes. Vapour deposition has some use in products but the newest development is application on continuous strip for car-body manufacture—the surface is smooth so that the subsequently painted surface has no unevenness. 

By means of an ingenious instrument which measured the wetness of a painted surface. Gay found that although the relative humidity of the atmosphere varies appreciably, this is not reflected in the behaviour of paint films. He found that under normal conditions paint films are saturated with water for about half their life, and for the remainder the water content corresponded with an atmosphere of high humidity furthermore, the relative humidity of sea-water is about 98%. It follows from Table 14.3 that the rate at which water passes through paint and varnish films is many times greater than the water consumed by an unpainted specimen exposed under industrial conditions or immersed in the sea. 

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