| 摘要 |
A process is provided herein for the continuous preparation of an oriented film of a polymer material. The process comprises the first step of shearing at least one film selected from the group consisting of a solution, a gel, or a mixture of a solution and gel, of the polymer material between at least one set of two solid surfaces which are in motion relative to one another and which, in a zone in which the shearing takes place, co-extend in closely adjacent face-to-face relationship, at least one of which surfaces is endless, so as to cause by such shearing, solidification of the polymer material from the solution, or the gel or the mixture of the solution and the gel to a degree sufficient that a coherent, oriented film of the polymer material is formed on one of the surfaces the film being sufficiently coherent to be capable of being removed from the surface on which it is formed. The second step involves continuously removing the, or each, oriented film of polymer material from the surface on which it is formed. The oriented polymer film so produced is also novel. For example, a novel oriented film of linear polyethylene is provided which has a Young's modulus greater than 50 GPa. |
