SCUFF RESISTANCE

Floor poHshes typically are evaluated for gloss, appHcation and leveling properties, discoloration, sHp resistance, scratch resistance, heel-mark resistance, scuff resistance, damp-mopping and detergent resistance, repairabiHty, lack of sediment, and removabiHty (3). RecoatabiHty and formula stabiHty are also important. A review of test methods is available (35). More than 20 ASTM test methods for floor poHshes exist. From the standpoint of product safety, sHp resistance is a particularly important variable and many test methods are available (39). 

Nylon 11 Nylon 11 is a hard abrasion-resistant, scuff-resistant coating. When correctly formulated and applied, it can be used for exterior application. It has good resistance to solvents and to a range of alkalis and salt solutions up to 80°C. If water quenched, the coating has excellent impact strength. However, Nylon 11 is crystalline and pull-back from sharp edges can be a problem. It is therefore essential that metal work is well radiused. 

Floor selection criteria should include chemical resistance, stain resistance, scuff and marring resistance, ability to radius cove, durability, esthetics, and ease of maintenance and repair. Table 3 lists several floor compositions and selection criteria. Special areas may require static dissipative or conductive flooring in order to minimize explosion potential with flammable material. 

Grades of acetal resins specifically designed to enhance the excellent lubricity of the material, without sacrifice in other properties, are known. These include Delrin AF, Ultraform N2311, and Celcon LW materials. Antistatic grades, particularly useful in electronic appHcations, have been developed. At least one recendy introduced new grade, Celcon SR90, claims good scuff resistance. 

Waxes. These are dispersions of polyethylenes, Fischer-Tropsh, Teflon, or vegetable waxes (qv) in a vehicle or solvent. They impart sHp and scuff resistance to ink films. Polyolefin waxes and Teflon are also available as powders that can be directly mixed into inks. 

Fillers. These are used to reduce cost in flexible PVC compounds. It is also possible to improve specific properties such as insulation resistance, yellowing in sunlight, scuff resistance, and heat deformation with the use of fillers (qv). Typical filler types used in PVC are calcium carbonate, clays, siHca, titanium dioxide, and carbon black. 

The shipment of many commodities may require special barriers on the sacks to impart resistance against hquids or vapors. Other treatments are used to provide grease resistance, acid resistance, and scuff resistance. Special coatings are used in sacks for packing commodities, eg, synthetic mbbers, asphalts, waxes (qv), and resins, to prevent the contents from sticking to the paper. 

Amino resins are used by the paper industry in large volume for a variety of apphcations. The resins are divided into two classes according to the mode of appHcation. Resins added to the fiber slurry before the sheet is formed are called wet-end additives and are used to improve wet and dry strength and stiffness. Resins appHed to the surface of formed paper or board, almost invariably together with other additives, are used to improve the water resistance of coatings, the sag resistance in ceiling tiles, and the scuff resistance in cartons and labels. 

Other requirements. These could include electrical insulation properties, including resistance to tracking and arcing, transparency, frictional properties, surface finish, scuff resistance and specific gravity. 

When this stage has been reached, the materials on the shortlist can be investigated further, checking suppliers, grades available, prices, processability and further details of the material properties, such as, for example, surface finish and scuff resistance, which do not normally feature in property tables. 

SB Service typical of engines operating in conditions such that only minimum protection of the type afforded by additives is desired. Oils designed for this service have been used since the 1930s they provide only anti-scuff capability and resistance to oil oxidation and bearing corrosion. 

Aesthetic properties snch as color, transparency, printability, scuff resistance... 

The relationship between the hardness of a surface and its resistance to scratching is evident (and, by analogy, polyester laminates can be scratched more easily than melamine)—but scratch resistance is influenced also by surface finish and colour. In general, scuff and scratch marks are more obvious on plane finishes (whether glossy or matt) and on dark colours than on textured finishes and light colours. Figure 62 illustrates this relationship. 

The solvent-extractable constituents of a wax may have significant effects on several of its properties such as strength, hardness, flexibility, scuff resistance, coefficient of friction, coefficient of expansion, and melting point. In... 

Rub resistance BS 3110 1959 (94). This is the resistance of a printed test piece to withstand rubbing against either another similar printed test piece or against a plain test specimen. The objective is to see that the ink/print has cured and will not scuff or smear in service. 

Another tough, clear film. Withstands steam sterilisation. Rather expensive. Only fair moisture resistance but good scuff resistance. Used in some laminations. 

Scuff and rub resistance—foil will abrade fairly easily (foil to foil, foil to product, etc.), producing dark particles. 

When the thermosetting overprint lacquer No. 1 (Table VII) was applied to aluminum foil and cured at 275 °F (135 °C) for 10 s, heat resistance of the coating was in excess of 500 F (260 C). The thermoplastic overprint lacquer No. 2, when dissolved in an alcohol-water blend, may be applied directly to the wet lithographic ink in order to improve gloss and permit the use of less expensive inks, eliminate starch sprays ordinarily used to prevent setoff, improve scuff resistance, and eliminate hydrocarbon effluents by replacing heat-set inks with oxidizing inks. 

SiUgen . [BASF BASF AG] Plasticizers, glazing agents, and silicone elastomers ad tives fximpiDvirig ease of sewing, scuff and tearing resistance of textiles. 

EPDM with ethylene-methacrylate-zinc. to improve the scuff resistance Dawson, 1993... 

For interior applications in public transport, another blend has gained widespread use — acrylic/PVC parts made by thermoforming. Its extruded sheets see use as benches, seat backs, armrests and window reveals for subways, railroad cars, buses, monorails and trolleys. Key properties that this alloy possesses include scratch and scuff resistance, and the ability to be cleaned easily using harsh detergents. 

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