RELATIONSHIP BETWEEN THE STRUCTURE AND THE SURFACE STATE OF THE SIMULTANEOUSLY BIAXIALLY STRETCHED POLY (ETHYLENE TEREPHTHALATE) FILMS

Autor: Hiroshi Ieki, Kiyoichi Matsumoto, Rikizo Imamura
Rok vydání: 1971
Předmět:
Zdroj: Sen'i Gakkaishi. 27:516-524
ISSN: 1884-2259
0037-9875
DOI: 10.2115/fiber.27.516
Popis: In this report, the orientation mode in the film plane and the relationship between the molecular structure and the surface state are discussed for the uniaxially stretched and simultaneously biaxially stretched poly (ethylene terephthalate) films prepared by wet-process.Sample films used in this study were the T-die extruded film with 140μ thickness. The uniaxial and the biaxial stretching of the films were done using a film-stretcher in a recirculating hot glycerin bath.The following results were obtained:(1) The crystalline orientation of simultaneously biaxially stretched films was random in the plane, however, that of two-way successively biaxially stretched films was selective to some extent.(2) The selective planar orientation parameter of the simultaneously biaxally stretched films was larger as compared with that of the uniaxially under constant width stretched films, in the machine direction and same stretch ratio.(3) The tautness-parameter of molecular chain in the simultaneously biaxially stretched films was smaller than in the two-way successively biaxially stretched films, but this tendency was reversed by the heat treatment under the fixed length.(4) The size of crystallite in the simultaneously biaxially stretched films was nearly equal in both the machine and the transverse directions.(5) On the electromicroscopic observation, the simultaneously biaxially stretched films with lower stretch ratio showed no charactristic surface structure, however, these films with higher stretch ratio represented the fibril-like structure.The molecular chain is locally uniaxially oriented in various directions in the plane, but the orientation is totally cancelled by averaging in the thickness direction which is due to the multilayer structure. That is, the simultaneously biaxially stretched films shows the uniplanar orientation.
Databáze: OpenAIRE
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