Coating weight

Product Substrate/fiber Coating Weight, Thick Density, Tensile Elongation Tear Water-vap Flex... 

Operation and Control. Control of a chromium phosphate conversion coating bath requires monitoring chromium and aluminum concentrations, active fluoride level, and temperature. Coating weight is very sensitive to active, ie, uncomplexed, fluoride. An innovative electrochemical method using a siHcon electrode (25) is employed for measuring active fluoride. A special precaution in chromium phosphate bath operation is the... 

Slot-die or extmsion coating involves the appHcation of molten polymer resin through a slot die directly onto the surface of a nonwoven. Upon extmsion, the resin is smoothed and quenched by a cooling roU. Coating weight is controlled by slot size and extmsion rate. 

Depending on the coating weight, nitrogen apphcation rate, and environmental conditions, SCUs can have residual characteristics which provide agronomic response from 6 to 16 weeks ki turfgrass apphcations. 

Nutrient release patterns vary with the amount of coating appHed and the substrate used. Coating weights vary from 10 to 20%. Typically, commercial products are blends of different coating weights. Coated substrates kiclude, but are not limited to, urea, potassium sulfate, and ammonium nitrate-based N—P—K fertilizers. 

A number of products are being marketed under the trade name POLYON. These include coated basic fertilizer materials, ie, urea, potassium nitrate, potassium sulfate, potassium chloride, ammonium sulfate, ammonium phosphate, and iron sulfate, in various particle sizes. Coatings weights on urea vary from 1.5 to 15%, depending on the release duration desired. Table 6 Hsts typical products. 

Material Density (g/cm 1 Coating weight (kg/m ) 0-025 mm thickness Brinell hardness Ratio of contraction stresses in sprayed deposits 0-51 mm thick Compressive strength (stress to collapse) (MN/m )... 

The oil film present on both types of tinplate and on newly hot-dipped tinware has a slight protective value. The passivation processes have much more effect but this is unlikely to compensate for a substantial reduction in coating weight. The effects of oil and passivation on the outside of tinplate cans may be reduced during can manufacture, filling and sterilisation. 

First comes the pretreatment stage. After rust removal and alkaline degreasing, a zinc phosphate formulated pretreatment (see Section 15.2) is applied by dip or spray-dip. Crystalline iron-rich zinc phosphate forms on the metal surface at a coating weight of 0.5-4.5 g/m. ... 

Phosphate coating solution Accelerator Immersion lime (min) Type of coating Coating weight (g/m )... 

Heavy phosphate coatings do not necessarily have better corrosion resistance than lighter coatings. Even with a single process, e.g. zinc/iron/ phosphate/nitrate, no consistent relationship has been found between corrosion resistance and either coating weight or weight of metal dissolved. 

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