Alkaline cleaning solutions

The transducers are typically mounted on an outside wall of the cleaning tank, but may also be mounted on the inside of the tank below the solution level in a sealed container. Alkaline cleaning solutions are typically at the same concentration and temperature as for a normal immersion cleaner, but the time required to clean may be less because of the ultrasonic effect. Like electrocleaning, ultrasonic cleaning produces an extremely clean surface. The main drawback is the relatively high cost. 

Installation of an ultrafiltration system that recovers 30 kg/d (65 lb/d) of waste oil and purifies 1135 kg/d (2500 lb/d) of alkaline cleaning solution for reuse, which resulted in a reduction of 5-day biochemical oxygen demand (BOD5) loadings to the treatment system of 200 kg/ month (370 lb/month). This avoided the need for installation of additional treatment. 

Substrate Characterization. Test coupons and panels of 7075-T6 aluminum, an alloy used extensively for aircraft structures, were degreased In a commercial alkaline cleaning solution and rinsed In distilled, deionized water. The samples were then subjected to either a standard Forest Products Laboratories (FPL) treatment ( 0 or to a sulfuric acid anodization (SAA) process (10% H2SO4, v/v 15V 20 min), two methods used for surface preparation of aircraft structural components. The metal surfaces were examined by scanning transmission electron microscopy (STEM) In the SEM mode and by X-ray photoelectron spectroscopy (XPS). 

Alkaline cleaning solutions contain builders (sodium salts of phosphates, carbonates, silicates, and hydroxides) and surfactants (detergents and soaps). Other additives may include anti-oxidants and stabilizers as well as small amounts of solvents. Acidic cleaning solutions may contain mineral acids (nitric, sulfuric, phosphoric, or hydrochloric), organic... 

De-oiling can be accomplished by recirculating a hot, strongly alkaline cleaning solution at 5% strength for 2 to 3 hours. Such solutions are not suitable where aluminum or zinc are involved. 

Food and beverages Resistance to alkaline cleaning solutions being steam sterilizable consistent pore size... 

Fig. 15 Mass changes of Zn films at open-circuit potential exposed to new (full line) and used (dash-dot line) alkaline cleaning solution. Electrodes Zn film on Au (with Cu overlayer) supported on 10-MHz AT-cut quartz crystal. Solution RIDOLINE industrial alkaline cleaner, pH 12.43. Temperature 316 K. (Reproduced from Ref [92] with permission from the Royal Society of Chemistry.)...

Polyethylene terephihalate (Mylar). A medium-strength bond can be obtained with polyethylene terephthalate plastics and films by abrasion and solvent cleaning. However, a stronger bond can be achieved by immersing the surface in a warm solution of sodium hydroxide or in an alkaline cleaning solution for 2 to 10 min. 

Excellent hydrotrope for use in alkaline cleaning solutions. Good stability to bleach under alkaline conditions. 

TRITON QS-44 is recommended primarily as a solubilizer of conventional nonionic surfactants in alkaline cleaning solutions at use concentrations. 

Alkaline cleaning solutions are caustic and can cause personal Injury if safety precautions such as protective clothing and ventilation are not rigidly followed. A list of common alkaline salts and detergents is given in Table 11-2. 

Note 4 Caution—It is essential that alkaline cleaning solutions are not used as changes in the viscometer calibration can occur. 

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