Studies on the stretching of polypropylene film. II. Polyaxial stretching

Abstract

-ku, Tokyo, J a p a n synopsis Polypropylene film was stretched polyaxially at 1O0-16O0C., and the orientation behavior was studied by means of optical and x-ray method. The molecular chains oriented progressively to the film surface with an increase in stretching area V A in the range 1-16, and the (040) selective uniplanar orientation developed at the extreme stretching. The plot of orientation versus V A was less steep when the stretching was carried out at higher temperature, but the final degree of orientation was independent of the temperature, because the final V A increased with temperature. At 160%. premelting occurred to such a degree that the high stretching and, consequently, the high orientation could not be obtained. The orientation of the amorphous chains was always behind that of the crystalline region. In the initial stage the polyaxial stretching was not as effective in attaining high biaxial orientation as the two-step biaxial stretching, but the final orientation was the same in both types of stretching because V A reached a value of 16 in the polyaxial stretching while it was only 2 in biaxial stretching.

Crystalline structure at surfaces of uniaxially drawn polypropene films

“…The process of drawing reduces the large-scale molecular organization and this can lead to the changes in the crystallite size and the deformation of the crystal unit cell [16][17][18] . It is interesting whether the reorganization of lamellar crystals in the surface layer induced by drawing occurs or not.…”

Studies on the biaxial stretching of polypropylene film. XII. Effect of crystallinity on the deformation mechanism of the biaxial stretching in one step

“…Figure 6 shows the change of wide-angle x-ray diffraction pattern of film 1 during biaxial stretching. It is clearly seen that the preferential planar orientation of (040) takes place during the biaxial stretching as it does in polyaxial stretching (1). Although the photographs are not shown, this trend of the preferential planar orientation of (040) is also observed in the cases of films 2 4 and in the case of film 1 stretched at lower temperature (140°C).…”

Influence of Cooling Water Temperature on Film Stretchability, Superstructure and Film Physical Properties of Random Copolypropylene in Double Bubble Tubular Process

“…The polarized incident light [6][7]2007 Influence of Cooling Water Temperature On Film Stretchability The measurement of the spherulite radius was based on the light scattering theory /26/ for perfect spherulites which gives A 15mW He-Ne gas laser (ΝΕΟ-Ι 5MS, Nihon Kagaku Engineering Co., Ltd.) was used as the polarized monochromatic (X=632.8nm) light source.…”