Process for the manufacture of polyester industrial yarn and cord made from said yarn and elastomeric objects reinforced with said cord

摘要

Manufacture of a multifilament polyester yarn which is suitable for use as an industrial yarn, particularly tyre yarn, and displays a specific breaking strength at high spinning speeds, the yarn is made in accordance with a process comprising the successive steps of spinning a molten polymer through a plurality of holes, cooling and drawing the resulting filaments, and finally collecting them, the polymer flow in each of the spinneret holes exhibits a core portion having a higher relative viscosity and a sheath portion having a lower relative viscosity, the difference between said relative viscosities amounting to less than 0,100, preferably 0,040-0,003.