Layer Formation on Porous Substrates

Dip dispersion coating is a colloid processing technique used as a method for the preparation of coatings. There are two possible compaction modes when a porous substrate is withdrawn from a dispersion  

Film-coating is the formation of an adhering dispersion layer as a result of the drag force exerted by the substrate during withdrawal from a dispersion. To achieve pure fihn-coating, the capillary suction of the porous substrate must be suppressed. The thickness of the entrained dispersion layer increases with increasing withdrawal speed and increasing dispersion viscosity. The contact 

1 Draining a fluid from a tube is included here. When the frame of reference is in the fluid it is considered dip coating. 

2 In practice coating fluids are often non-Newtonian dispersions. The complete rheological behaviour is then of importance. 

6 — PREPARATION OF ASYMMETRIC CERAMIC MEMBRANE SUPPORTS BY DIP-COATING 

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