Injection mold with surface coating of inner surface

Abstract

Blow molds for PET bottles have an inner surface of the PET which is in contact with heat during the blowing operation, which is coated with a layer of a ceramic material having a nanoscale thickness, at least one thickness layer of which is obtained by ALD technology Deposited Al2O3 and / or TiO2. Thanks to this technique, the PET preforms experience less friction during contact with the interior of the mould.

Description

technical field [0001] The invention relates to the field of producing containers made of thermoplastic material. In particular, it relates to a mold that reduces the physical and chemical reaction between the molten PET material and the steel surface of the molded part of the mold during the injection step in the process for molding preforms, thereby reducing friction . Background technique [0002] During injection moulding, the transformation of a polymeric material, typically a thermoplastic such as PET in pellet form, to an article with a defined shape takes place. The process begins with the high-pressure injection of molten material into a molding cavity, usually with walls made of steel, and ends with the removal of the preform from the mold after solidification by cooling. Cooling pattern and time are critical factors in the molding process. By cooling time it is meant the time during which the components are inside the mould, but there is no longer flow of molte...

AI Technical Summary

Problems solved by technology

To date, however, no solution is known that would improve the production of preforms with thin walls, and for preforms with L less than 100 mm and with L / t ratios > 45 and for preforms with L ≥ Both 100 mm and thin-walled preforms with L / t > 50, there are technical limitations, as previously disclosed

A further disadvantage of conventional molds is the difficulty of opening and removing the preform from the mold (demoulding)

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