Particulate soiling

As might be expected, large differences in the removabiUty of soHd particulate soil are due to differences in the chemical nature of the particle surface. Thus, kon oxides, lampblacks, and clays, all of the same particle size, differ greatly in thek redeposition behavior and the manner in which they are removed. 

Proteia and starch stains are removed by proteases and amylases, respectively. Fats and oils are generally difficult to remove at low wash temperatures by conventional detergents. By usiag Upases, it is possible to improve the removal of fats/oils of animal and vegetable origin even at temperatures where the fatty material is ia a soUd form. Particulate soils can be difficult to remove, especially if the particle sise is small. Removal of particulate soil from cotton fabric can be improved by use of a ceUulase which removes cellulose fibrils from the surface of the yam. 

Raheel, M. (1991) Pesticide transmission in fabrics effect of particulate soil, Bull. Environ. Contam. Toxicol., 46 845-851. 

Cambardella CA, Elliott ET (1992) Particulate soil organic matter changes across a grassland cultivation sequence. Soil Sci Soc Am J 56 777-783... 

Thus the consideration of kinetics of POP sorption by particulate soil organic matter appreciably changes the pollutant vertical distribution, particularly during the clearance period, which increases this period substantially. Accordingly, this is of great importance to environmental risk assessment of POPs exposure to living organisms. 

The determination of the quantity 4, the fractional increase in cleaning frequency due to particulate matter, is the difficult part of the problem. The data of chelson and Tourin (cited in Spence and Haynie ) suggest a value of v for paint of 1.5/yr. The value of Q is obtained as follows According to Noble, the annual production of paint in 1968 was 2.59 billion. Because the economic life of paint is considered to be 4 yr, 10.36 billion worth of paint is in place, of which only 70% is exposed to atmospheric pollutants. Thus, 7.25 billion is the manufacturers value of in-place paint exposed to air pollution. Using a labor factor of 3.3, the total in-place value of paint is 23.9 billion. Because i - 1.5 for particulate soiling, the cost of pollution damage (cleaning costs) is some 36 billion/yr. 

Each component has a specific function. The Metasilicate will increase paint stripping efficiency provided sufficient alkalinity is present. The Gluconate or Glucoheptonate provide the derusting. Burco TME and Burco ADS-100 provide removal and dispersion of particulate soils while the Dodecylbenzenesulfonate adds wetting and oily soil detergency. Each component can be adjusted according to the improvement needed. 

Amylase facilitates the removal of starch-containing stains such as those from pasta, potato, gravy, chocolate, and baby food. Dried-up starch is difficult to remove from medium- to low temperatures. Amylase adheres to the surface of laundry, acting as an adhesive for other stain components. Starch acts as a kind of glue which binds particulate soil to the surface. Amylase hydrolyzes the starch into dextrins and oligosaccharides the latter are readily dissolved in the washing liquor and thus successively diminish the stain. Likewise, dried-on food, in particular stains and films from starch-containing foods, may be difficult to remove in a dishwasher. 

Nature of the soil Oily soil or particulate soil, hydrophobic or hydrophilic, liquid or solid... 

Particulate soil is removed from fibres by a two-step process. First, a thin layer of wash liquid penetrates between the particle and the fibre surface, enabling surfactants to adsorb onto the particle surface (Fig. 7.1). Then, the particle becomes solvated and is transported away from the fibre and into the bulk of the wash liquid by mechanical action. Finishes that are hydrophilic (enhancing penetration of the fibre-soil interface) with low adhesion to soil under washing conditions should improve particulate soil release. Ablative or sacrificial finishes... 

Additional finish characteristics that should facilitate oily soil release include the ability of the finish to swell during the washing process and flexibility under mechanical action. As in particulate soil release, sacrificial finishes are expected to benefit oily soil release. 

Evaluation of soil-release effects after washing is mostly visually done by comparison with photographic standards, but also by reflectance measurements and other instnimental techniques, including microscopy. Reflectance data using the Kubelka-Munk equation correlate fairly with the oily soil content but not with residual particulate soil (which is probably partly buried within the fabric and shielded from the light path). ... 

Polymeric dispersant and protective colloid for yarn and fabric preparation and bleaching. Minimises scale build-up on hot metal surfaces and fabric. Extremely efficient dispersant for cotton linters and particulate soil. Provides a cleaner fabric after washing-off without drainage marks. Improves absorbency and dyeing properties. 

Solvent scours for preparation of synthetics and blends. Offer good wetting and emulsification for removal of oils and particulate soil. Does not lose power at high temperature has excellent stability at the boil, can be used in singlebath scour and dye systems or in continuous processes. 

Although MTBE has a reasonably high water solubility, it shows little tendency to degrade from hydrolysis and very little tendency to adsorb to suspended particulates, soils, or sediments. In groundwater, MTBE can be fairly persistent since it shows limited susceptibility to either anaerobic or aerobic biodegradation. 

Eluviation. The transportation of dissolved or particulate soil material from one area or specific horizon of the soil to another by the movement of water. 

Illuvial. Pertaining to the deposition of dissolved or particulate soil material into one area or horizon of the soil from another. This material is transported by the process of eluviation. 

Solvent cleaners are generally free of builder salts. The cleaning efficacy depends on solvent-type compounds, such as glycol ethers. Solvent cleaners are less effective on particulate soiling, such as mud on floors however, they are effective against oily soiling, particularly on modern plastic surfaces. 

Water-soluble soils Particulate soils Fats/oils Proteins source Carbo- hydrates Bleachable dye source... 

The ease of removing particulate soil from the hair surface is also dependent upon particle size. As size decreases, the surface area per unit weight of the particle, and consequently the area of actual contact per unit weight between particle and substrate, increases. As a result, more force per unit area is required to remove the particle [120], In a normal cleaning process, particulates that are less than 0.1 tun in size cannot be effectively removed from fibrous substrates [121]. 

Although grease is the main soil target, followed by particulate soil, for allpurpose cleaners they may also be tested against other nonkitchen problems such as soap scum. Soap scum testing is described in the section on bathroom cleaners. 

True to their use as floor cleaners, similar trends are seen in the formulation of floor cleaning wipes. There are wipes where soap is the main cleaning surfactant [281], and ones where there are formula ingredients to entrain the particulate soils [282],... 

Particulate Soil Removal of particulate solid soil by aqueous baths is accomplished by the following mechanisms ... 

Since the adsorption of nonionics onto soil or substrate does not significantly increase its electrical potential at the Stem layer, this mechanism of soil removal is probably not a major one for nonionics, and nonionics are generally not as effective as anionics for the removal of particulate soil (Albin, 1973). On the other hand, they appear to be very effective for producing steric barriers (see below) for the prevention of soil redeposition. 

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