Coated abrasive flexing

This material finds a limited application in films and coatings which require good abrasion and flexing resistance. Some typical properties of cross-linked and uncross-linked polymers are given in Table 18.9. 

Thicker epoxy-based coatings, highly flexibllized with amine-reactive nitrile liquid polymer, have been described by Mendelsohn (50) in which the flexibilizing hardener is comprised of an admixture of ATBN, fatty polyamide and boron trifluoride/amine complex. This coating ages well at 100°C and has excellent toughness/ flex with good abrasion and vibration absorption properties. 

The molecular construction of Dow Primacor copolymers creates internal toughness, abrasion resistance, puncture resistance, and high environmental stress-crack resistance (ESCR). Flexible coatings with good flex-crack resistance and exceptional elongation are possible. 

Uses Urethane for coatings/finishes tor syn. textile fabrics that must have permanent fire retardancy, e.g., syn. pleated shades, vertical blinds Features Solv.-free produces tough, flexible dry film, stiff hand, exc. molding/pleating props., exc. UV resist. exc. low temp, flex crack resist., abrasion resist. 

Uses Binder in pigmented surf, coatings, syn.-resin-bound plasters, renderings, exterior masonry coatings cobinder with inorg. binders improving adhesional bond str.. flex, bond str.. flexibilily. abrasion resist., and workability... 

Chem. Descrip. PEEK, 30% carbon fiber-filled Uses PEEK for inj. molding, compr. molding, extrusion, coating Features Exc. flex, and tens. str. and elec, props, at high temps., toughness and abrasion resist., exc. flamm. rating, wide chem. resist. 500 F max. continuous service temp. 

The fabric substrate used for the filter media will need to provide certain characteristics, dependent on the application. The typical properties required include abrasion resistance, stretch resistance, dimensional stability, and resistance to flex fatigue. All these performance criteria can be assessed by using suitable test methods. The fabric will also be tested for correct warp and weft sett, air permeability, thickness, density, and fabric tensile properties. All the factors will affect the performance of the filter as they are directly related. If woven fabrics are considered, the porosity will be directly related to the sett and therefore air permeability. The combinations of the fibre types, fabric constructions, and coating substrate will provide the filter manufacturer with a range of properties for use in a range of appUcations. 

These materials find limited application in coatings where good abrasion and flexing resistance are required. It may be noted that nylons may be A -methylolated by treatment with formaldehyde but the products are too unstable to be of commercial use. 

Paint films also may be required to resist acids and alkalis, solvents, staining, heat, impact, marring, and abrasion. Some coatings must be able to withstand flexing without cracking or flaking. Table 5 lists paints that have proven successful in withstanding mechanical and chemical action. 

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