Metal surface cleaners

Metals treatments Metal sulfides Metal surface cleaners Metal surface treatment Metal surface treatments... 

They readily dissolve metal oxides and are effective metal surface cleaners and fluxes (see Metal surface treatments). They also have bactericidal and fungicidal properties (74). However, the main commercial appHcation among monofluorophosphates is of sodium monofluorophosphate ia dentifrices. 

Antifoulants or metal surface cleaners to reduce the risk of pitting corrosion and other forms of concentration cell corrosion initiated at the metal surface by shielding effects from inorganic deposits. These could also be called deposit control agents. 

Apart from the materials described earlier, formulations usually include other organics, including coupling agents, antifoams, and surfactants. A commonly employed raw material is polyethylene glycol (PEG) in the form of perhaps PEG-8 oleate or PEG-6 distearate. This surfactant material is used as a metal surface cleaner. It prepares the metal surface to receive inhibitors and improve DCA surface mechanisms. 

Because of the ability of glucoheptonates to chelate calcium and iron and dissolve rust films without attacking the bare metal, they are very useful as metal surface cleaners. They are often considered a ferrous corrosion inhibitor, but the real function of these chelants is their ability to dissolve iron- and calcium-rich deposits on the metal surface, within a pH range of 5 to 9, and to provide clean metal surfaces. Thus they permit access by other true corrosion inhibitors and help to minimize differential aeration and under-deposit corrosion mechanisms. 

Uses Wetting agent, spreading agent, surfactant for all-puqiose cleaners and degreasers, patio furniture cleaners, vinyl and aluminum siding cleaners, neutral floor cleaners, concrete floor cleaners, hard surface cleaners, cleaners, metal surface cleaners, neutral floor cleaners, transportation equip. 

Acid cleaners based on sulfamic acid are used in a large variety of appHcations, eg, air-conditioning systems marine equipment, including salt water stills wells (water, oil, and gas) household equipment, eg, copper-ware, steam irons, humidifiers, dishwashers, toilet bowls, and brick and other masonry tartar removal of false teeth (50) dairy equipment, eg, pasteurizers, evaporators, preheaters, and storage tanks industrial boilers, condensers, heat exchangers, and preheaters food-processing equipment brewery equipment (see Beer) sugar evaporators and paper-mill equipment (see also Evaporation Metal surface treati nts Pulp). 

Alkylphenol ethoxylates are chemically stable and highly versatile surfactants that find appHcation in a large variety of industrial products including acid and alkaline metal cleaning formulations, hospital cleaners, herbicides (qv) and insecticides, oil-weU drilling fluids, synthetic latices, and many others (see Disinfectants AND antiseptics Elastop rs, synthetic Insect control technology Metal surface treati nts Pesticides Petroleum, drilling fluids). 

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. 

Removing suspended solids, decreasing cycles of concentration, and clarification all may be beneficial in reducing deposits. Biodispersants and biocides should be used in biofouled systems. Simple pH adjustment may lessen precipitation of certain chemical species. The judicious use of chemical corrosion inhibitors has reduced virtually all forms of aqueous corrosion, including underdeposit corrosion. Of course, the cleaner the metal surface, the more effective most chemical inhibition will be. Process leaks must be identified and eliminated. 

Care must be taken here not to confuse acid cleaners with the high-strength, phosphoric acid-based chemical polishes and chemical brighteners, which are used specifically to obtain the surface finish which such materials produce. Also in the category of acid cleaners could be considered the lightweight alkali-metal phosphating cleaner-coater solutions, but a discussion on such materials is best left to specialist publications on metal pretreatment chemicals. 

Today, boilers are welded and stress-relieved, thus ostensibly eliminating a primary component of the SCC process however, modem boilers operate at higher heat fluxes, which imposes a strict requirement for cleaner metal surfaces. The presence of deposits on any waterside surface may provide an opportunity for the concentration of free alkali under the deposit, and so caustic embrittlement still occurs today, depending on inherent stress levels and the particular water chemistry involved. 

Figure 10.1 Types of phosphate structures, (a) Where x = 12 to 14, the structure represents sodium polyphosphate, a phosphate typically used in HW heating and industrial steam boiler formulations. The structure is ill defined and described as glassy rather than crystalline. Where x = 2, it represents sodium tripolyphosphate, (b) This is the structure where effectively, x = 0, and represents trisodium phosphate (sodium orthophosphate), which is commonly supplied in either crystalline or anhydrous powder form and used as an alkalinity booster, boiler boil-out cleaner, and metal surfaces passivator.

Alkaline baths, in tin refining, 24 789 Alkaline batteries, 15 611 Alkaline catalysts, in phenolic resin polymerization, 18 762-765 Alkaline cleaners, for metal surfaces,... 

Phosphoric acid is used as an intermediate in the production of animal feed supplements, water treatment chemicals, metal surface treatments, etching agent, and personal care products such as toothpaste. It is used as a catalyst in the petroleum and polymer industry. Phosphoric acid is used in food as a preservative, an acidulant, and flavor enhancer it acidifies carbonated drinks such as Coca Cola and Pepsi, giving them a tangy flavor. Phosphoric acid is used as a rust remover and metal cleaner. Naval Jelly is approximately 25% phosphoric acid. Other uses for phosphoric acid include opacity control in glass production, textile dyeing, rubber latex coagulation, and dental cements. 

The most common and best known chelant is ethylenediaminetetraacetic acid (EDTA). The related compounds diethylenetriaminepentaacetic acid (DTPA) and nitrilotriacetic acid (NTA) are also well known (Figure 10.2). EDTA is a powerful chelant that complexes strongly with most metal ions to form six-coordinate complexes. It has therefore become the first choice in most applications. Indeed, a search of the bathroom cabinet will spot EDTA on the ingredient list of many personal care formulations. DTPA is also a powerful chelant, but tends to be used more often in industrial settings. NTA has only four binding sites and is used more often where hardness ions require control, such as in cleaning, for example, hard surface cleaners, dishwashing, and the dairy industry. 

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