Deformability coating

Mount DL, Schwortz JB. Formulation and compaction of nonfracturing deformable coated beads. Drug Dev Ind Pharm 1996 22(7) 609-621. 

A semi-permeable film can be used, which is impermeable to the photoformable composition but is permeable to a deformable-coating-mixture that is non-wetting and immiscible with the photoformable composition. 

The deformable-coating-mixture passes through the membrane by diffusion and forms a thin, slippery surface on the photoformable composition side of the membrane, thereby eliminating any adhesion forces caused by chemical, mechanical or hydrogen bonds. 

Adhesion test, bend A comparative adhesion test in which the coated substrate is bent around a rod with a specified diameter. The deformed coating is observed visually and subjected to a tape test. 

Rehbinder and co-workers were pioneers in the study of environmental effects on the strength of solids [144], As discussed by Frumkin and others [143-145], the measured hardness of a metal immersed in an electrolyte solution varies with applied potential in the manner of an electrocapillary curve (see Section V-7). A dramatic demonstration of this so-called Rehbinder effect is the easy deformation of single crystals of tin and of zinc if the surface is coated with an oleic acid monolayer [144]. 

Enamel is appHed to steel in the flat before fabrication. Cans manufactured by the draw and ironing operation must be coated internally after fabrication because of the metal deformation with surface dismption that takes place. 

Testing of Painted Products. The enhancement of paint adhesion is one of the principal functions of conversion coating (20—22). A group of tests based on product deformation is used to test the painted product. The appHance and cod-coating industries use the mandrel bend, the cross-hatch adhesion test, and the direct and reverse impact tests. Adhesion after a water soak is judged using a cross-hatch test performed on the exposed surface. 

Lighting. An important appHcation of clear fused quartz is as envelop material for mercury vapor lamps (228). In addition to resistance to deformation at operating temperatures and pressures, fused quartz offers ultraviolet transmission to permit color correction. Color is corrected by coating the iaside of the outer envelope of the mercury vapor lamp with phosphor (see Luminescent materials). Ultraviolet light from the arc passes through the fused quartz envelope and excites the phosphor, produciag a color nearer the red end of the spectmm (229). A more recent improvement is the iacorporation of metal haHdes ia the lamp (230,231). 

Coating solutions often exhibit a mixture of viscous and elastic behavior, with the response of a particular system depending on the stmcture of the material and the extent of deformation. Eor example, polymer melts can be highly elastic if a polymer chain can stretch when subjected to deformation. 

Thermoplastic coatings based on vinyl plastisols and acryUc latexes resist severe deformation duting fabrication and exhibit good exterior durabdity. 

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