Verfahren und Vorrichtung zur Herstellung synthetischer Flaschenverschlüsse

摘要

A process for producing synthetic bottle closures composed of a cylindrical core element made of foamed plastic, and a surrounding compact and unfoamed plastic outer layer, comprises forming plastic melts in primary and secondary extruders, joining them in a distribution tool, and hardening. The plastic melt for the core material (1) is mixed and cooled between the primary extruder (13) and the distribution tool (17). A chemical propellant is added to the melt before the extruder inlet, and the melt pressure is adjusted to 130-200 bar at the worm tip, and 50-100 bar at the outlet nozzle (18). A static mixer (14) is located between the extruder and the distribution tool.