| abstract |
A 10- to 200 µm-thick, transparent high-density polyethylene film of 0.935 g/cm 3 more in density having a haze value of less than 10%. It has a surface roughness of 0.001 to 0.15 µm, a C-axis orientation function (Fc) within the film of 0.10 to 0.50, and a difference in refractive index An between the amorphous portion and the crystalline portion within the film of 0.1000 to 0.1070. This film is produced by passing raw film through three heating rolls, i.e. a first heating roll (R 1 ), a second heating roll (R 2 ), and a third heating roll (R 3 ) which are so heated that the temperature of R 2 is higher than that of R 1 and R 3 , and that the temperature of R 2 is not higher than the m.p. of the film and not lower than 105°C, and cooling the film. The film thus obtained has an excellent transparency, well-balanced strength in a machine direction and a transverse direction, remarkably large impact strength, and high Young's modulus, and is suited for use as wrapping film for containers of cigarettes, caramels, chocolates and confectionery such as chewing gum or candy. |