Flash paint

Dynamic viscasily at 25°C ar paur paint (mPa s) Refractive index at 60°C Salability Flash paint (°C)... 

Another factor which may become increasingly important is the flash point. Unfortunately there is no simple relation to estimate flash points of mixtures, so this limits the accuracy of flash paint restrictions in the linear programming technique. We have included an option to maintain the flash point above a given value. Since the additivity is based on simple volume fraction additivity of the flash points, this option can only be considered a very rough guide. 

AMINES Bomno Rpnoo 5-95% 760 mm Hg Vppor Pross. 25 C CPS Solubility % by Wl. 2 C Ftaaxa Polnl FIra POlOl Flash Paint... 

An interesting appHcation is the study of aerosols, such as sprayed paint. A flash hologram of the paint spray at a convenient magnification records positions and sizes of the particles ia the hologram. This image can then be studied at leisure at higher magnification for size and shape of iadividual particles. 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

Inhibited grades of 1,1,1-trichloroethane are used in hundreds of different industrial cleaning appHcations. 1,1,1-Trichloroethane is preferred over trichloroethylene or tetrachloroethylene because of its lower toxicity. Additional advantages of 1,1,1-trichloroethane include optimum solvency, good evaporation rate, and no fire or flash point as determined by standard test methods. Common uses include cleaning of electrical equipment, motors, electronic components and instmments, missile hardware, paint masks, photographic film, printed ckcuit boards, and various metal and certain plastic components during manufacture (see Metal surface treatments). 

To reduce the amount of dust produced, water can be added to the abrasive from a circular water sprayer around the no22le. Chemical corrosion inhibitors must be dissolved in the water to prevent flash msting of the steel. Newer methods to reduce dust include the use of ice, soHd carbon dioxide (dry ice), or plastic beads as abrasives. Blasting with dry ice is inexpensive and effective, but the accumulation of carbon dioxide must be avoided in enclosures. Plastic beads are inexpensive, but the cutting efficiency is low and paint removal is slow the beads can be cleaned of paint particles and reused. 

Advantages over dipping are numerous there is no sagging and no blocked threads or holes the cover on edges, welds and seams is superior box sections are uniformly coated Coating of mixed components is possible, with virtually 100% paint usage and, above all, because the paints are water-borne, there is no necessity for flash off zones or fire protection. 

Electrodeposition This method of paint application is basically a dipping process. The paint is water-based and is either an emulsion or a stabilised dispersion. The solids of the paint are usually very low and the viscosity lower than that used in conventional dipping. The workpiece is made one electrode, usually the cathode, in a d.c. circuit and the anode can be either the tank itself or suitably sized electrodes sited to give optimum coating conditions. The current is applied for a few minutes and after withdrawal and draining the article is rinsed with de-ionised water to remove the thin layer of dipped paint. The deposited film is firmly adherent and contains a minimum of water and can be stoved without any flash-off period. This process is used for metal fabrications, notably car bodies. Complete coverage of inaccessible areas can be achieved and the corrosion resistance of the coating is excellent (Fig. 14.1). 

Methyl Acetone. Commercial product .a water-white, anhydr liq, consisting of various mixts of acet (45 to 65%), methyl acetate (20 to 30%) and methanol (20 to 40%). Density about 0.83g/cc, boiling range 50 to 70°, flash p near 0°F. Miscible with hydrocarbons, oils and w. Obtained as a by-product in the manuf of acet and methanol from wood distn, representing fractions which cannot be economically sepd. The mixt can be used as such, being an excellent solv and plasticizer for NC and other cellulose esters, such as the acetate. It also dissolves rubber, gums, resins, lacquers, paint and varnish Refs 1) T.H, Durrans, Solvents , Van-Nostrand, NY (1938), 122 2) CondChemDict... 

After flash-off periods at defined relative humidities, the paints were scraped from the panels and dissolved in the cathode solution. 

The dry ice blaster is an effective and mess-free method for in-place cleaning that eliminates the need to disassemble machinery before it is cleaned. Compressed air propels tiny dry ice pellets at supersonic speeds so they flash freeze and then lift grime, paint, rust, mold, and other contaminants from metal surfaces. Pellets vaporize quickly into the air, leaving no wastewater or solvents, only the soiled contaminant to be swept up. 

A number of these combs are fixed side by side with spacers in a carrying plate. The tips of the combs are then dipped into a solution of paint-like consistency containing flashing compositions to be described... 

During the production of paint, it is important to keep control of the temperature. Due to the high shear forces a substantial amount of heat is produced especially in the pearl mill. Some ingredients in the paint are sensitive to heat, e.g. solvents which will have the risk to flash off. Therefore additional cooling is normally needed in this operation. Figure 9 shows a flow diagram of paint production in a factoiy. 

Substrates, Paints and Coatings. Both flash rusting and underfilm darkening studies exployed a white, pH 4.5, primer formulation (see Appendix), designated as Standard, based upon Haloflex 202, a chlorine-containing vinyl acrylic latex. A zinc phosphate free formulation, designated as Non-Standard, of pH6 was prepared by substitution of zinc phosphate for barytes. The comparison paints were a commercial butyl acrylate-methyl methacrylate water borne primer, formulated at pH 9, and a solvent based chlorinated rubber primer. 

Flash Rusting (Bulk Paint and "Wet" Film Studies). The moderate conductivity (50-100 ohm-cm) of the water borne paint formulations allowed both dc potentiodynamic and ac impedance studies of mild steel in the bulk paints to be measured. (Table I). AC impedance measurements at the potentiostatically controlled corrosion potentials indicated depressed semi-circles with a Warburg diffusion low frequency tail in the Nyquist plots (Figure 2). These measurements at 10, 30 and 60 minute exposure times, showed the presence of a reaction involving both charge transfer and mass transfer controlling processes. The charge transfer impedance 0 was readily obtained from extrapolation of the semi-circle to the real axis at low frequencies. The transfer impedance increased with exposure time in all cases. 

Table I shows that the corrosion rate in the Standard pH i(.5 paint was larger than that in the Non-Standard (zinc phosphate free) paint at pH 6, with all rates decreasing with time. The rates decreased with further increase of paint pH to 8. The increased tendency of flash rusting with increase of pH from 6 to 8 was, therefore, associated with lower substrate corrosion currents. Comparison between Non-Standard and Standard paint adjusted to pH 6 with NHj showed little difference in corrosion rates implying that pH was more influential than the presence of zinc phosphate at this pH. Adjustment of the Non-Standard paint with HjSO to an equivalent pH 4.5 of the Standard paint showed good agreement between corrosion rates. This result also indicated pH to be more influential than the presence or absence of zinc phosphate with regard to corrosion currents. The absence of flash rusting at pH 4.5 is therefore associated with higher corrosion currents.

For some purposes (manufacture of varnishes and paints), substitutes for oil of turpentine (pinewood oil, mineral oils) are now admitted, since they are almost or quite colourless and non-fluorescent, while they emit no unpleasant odour, do not alter the tint of varnishes or paints, have the same solvent properties as oil of turpentine and have specific gravities and flash points not greatly inferior. 

Some confusion has existed as between paints which are in themselves noncombustible and those which have the ability to prevent wood from entering into combustion. The Navy uses a noncombustible paint for metal to prevent flash fires following explosions. This paint was designed to protect metal against the elements and not contribute fuel to fire situations, as would ordinary oil paint, enamel, and varnish. 

Throughout the paper, the termf fire-retardant paint means a paint which does not flash or flame when exposed to a source of ignition. The intended purpose of... 

Results. None of the observers reported flaming, flashing, or glowing of any portion of the exposure deck or outboard bulkhead paint films during the test, although following test, it was noted that all the paint systems were discolored or blistered and peeling, particularly the experimental red deck paint (system 5). The temperature recorded showed a maximum of 436 F. on the bulkheads, 480 F. on the weather deck, and 888 F. ambient over the center of the fire. As the bulkhead thermocouples were... 

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