Dirt pick

Acoustical tile was specified for all ceilings, with the engineering firm selecting the appropriate tj pe. Perfonnance was good, the tiles seemed to have a low dirt pick-up, and dust deposits near the ventilation outlets w ere minimal. 

Poly(butyl methacrylate) (PBMA) began to be used as a picture varnish in the early 1930s. It encountered a considerable success because of its resistance to yellowing, adequate flexibility, no dirt pick-up and good solubility in nonpolar hydrocarbon solvents. Products based on PBMA, such as Elvacite 2044 and Elvacite 2045 by Du Pont, were abandoned when it was discovered that under light exposure they cross-link to an unexpected extent becoming insoluble [64]. From this point of view acrylic copolymers based on methyl and ethyl acrylates/methacrylates show a much better long-term stability. 

Figure 4.17 New nanobinder Col.9 combines in one product the advantages of conventional coating types in terms of low dirt pick-up, chalking and rack resistance, and colour retention. (Reproduced from Col.9.com)...

By contrast, conventional, nonreactive surfactants, apart from water uptake and the resulting drawbacks, may cause a permanent reduction in surface hardness, poor blocking resistance, inferior sandability and dirt pick-up. These effects were already observed by Van-derhoff in the early 1950s and were confirmed more recently by Hellgren et al. using the atomic force microscopy (AFM) technology [13]. 

Elastomeric roof coatings made from acrylic emulsions have an advantage over low-grade asphalts which are prone to deterioration. Roof coatings based on acrylic copolymer emulsions are tough and flexible. Superior resistance is shown to water ponding along with dirt pick-up resistance and reflectivity. 

However, three areas fire retardancy, dirt pick up, and surface tack do exist as outstanding issues in this field and solutions to them exist. Perhaps future work will address these problems. 

Uses Used in any type of coating (varnish, stain, solv.- or water-based, bake or air dry enamels) food pkg. coatings Features Exc. weather durability, water repellency, improved salt spray and humidity resist., improved slip and mar resist. min. effect on dirt pick-up, gloss, and clarity preserves integrity of thermoplastic coatings Reguiatory FDA 21CFR 175.300... 

While working a HAZOP of a water distribution system, we found that reversing flow for emergency reasons created additional hazards to our process. One of the new hazards was critical safety valves and pumping stations could be blocked from contamination from dirt picked up from reverse flow through our filters. 

The primary causes for these changes are usually chemical reactions in the film, though physical properties cause dirt pick-up and flow or production of stresses. The agents of deterioration - light, heat and oxygen - act on the weak-... 

Wagner, O., Baumstark, R. (2002). How to control dirt pick-up of exterior coatings. Macromo-... 

Dirt pick-up Dirt pick-up is the tendency of a dry film to attract soiling material to its surface. The soiling may be resting on the surface, and so be more or less removable, or be retained within the structure of the film. 

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