摘要 |
<p>A method of forming a layer of material from a solution containing the material and a solvent which comprises the steps of forming the solution into a layer, contacting at least one major face of the solution layer with a wall which is permeable over the area of that face substantially to the vapor phase only of the solvent, and effecting the escape of solvent simultaneously from both major faces of the layer including the one major face by vapor diffusion through the wall so as to set the layer.</p> |