ポリエチレン繊維の製造に関する研究

第6報 繊維の強伸度的性質について

抄録

The melt spinnings by the so-called candle melt spinning apparatus of several low pressure polyethylenes, _??_n of which range from 4×10⁴ to 15×10⁴, were carried out at about 250°C, and temperatures higher at than 300°C. The hot drawing of undrawn filaments was carried out at 80°C and 95°C in the hot water bath.
Mechanical properties, crystallinity of undrawn filaments are as follows. The characteristic values of the small deformation of filaments such as stress at yield point are scarecely dependent on the _??_n of the sample, while those of the large deformation of filaments such as constant stress range, tensile strength and elongation are largely dependent on the _??_n of the sample. The stressstrain curves of filaments having, larger _??_n obtained by the spinning at higher temperature than 300°C resemble to those of the filaments having smaller _??_n and spun at lower temperature. The densities of filament range from 0.928 to 0.944, varying with _??_n and drawing conditions and are largely effected by quenching at the spinning process.
The maximum draw ratio at hot drawing is larger with smaller _??_n and the better results are obtained by drawing at 95°C than 80°C.
Some properties of drawn filaments are as follows. The tensile strength and the initial elasticity increases and the elongation decreases with increas draw ratio. The tensile strength at 30% elongation obtained by the interpolations are remarkably affected by _??_n and generally higher than 4g/d, and as a rule at smaller elongation the tensile strength exceeds over 5_??_6g/d. The effect of _??_n on the initial elasticity is not large. Several percent increase of tensile strength and decrease of elongation are obtained by the heat treatment. The densities of drawn filaments increase by drawing and heat treatment.