CPC B29C 43/34 (2013.01) [B29C 43/52 (2013.01); B29C 2043/3433 (2013.01); B29C 2043/5816 (2013.01); B29C 2043/5833 (2013.01); B29K 2101/12 (2013.01)] | 11 Claims |
1. A method for producing an object made of polymeric material, said polymeric material being a semi-crystalline material and having a melting temperature and a crystallization temperature, the method comprising the steps of:
melting the polymeric material;
after the step of melting, cooling the polymeric material below the melting temperature in a cooling zone;
using a severing element, severing a dose from a continuous flow of polymeric material coming from the cooling zone and exiting from a nozzle;
obtaining said object by shaping the dose in a mould between a male forming element and a female forming element which move towards one another with a mutual movement speed, the dose having a temperature lower than said melting temperature,
wherein the flow of polymeric material moves with an advancement speed along a path starting at the cooling zone and reaching the severing element, the method further comprising the step of accelerating the flow of polymeric material outside the mould prior to severing the dose therefrom, the flow of polymeric material being accelerated downstream of the cooling zone so as to have an advancement speed greater than the advancement speed the polymeric material had in the cooling zone, whereby an accelerated flow of polymeric materials exits from the nozzle along a direction and the dose is severed from the accelerated flow and released into the mould while the mould is arranged in an open configuration, wherein the step of accelerating the flow of polymeric material is carried out while the polymeric material is at a temperature comprised between the melting temperature and the crystallization temperature.
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