Gas assisted injection moulding: adding two components and moveable inserts

Abstract

Gas assisted injection moulding (GAIM) is a technique that is successfully used for compensating shrinkage during injection moulding of thick walled but still accurate products with low levels of internal stresses and frozen-in orientation. In this study the authors apply GAIM in moulding 28 mm thick products combining the technique with two component injection moulding: 2C-GAIM. Next, the authors used a movable insert as a local shrinkage compensating device, making the use of gas superfluous: the component, component, compliance, compensating for shrinkage technology is born. It is used for injection moulding robust and accurate transparent polymer products aiming to introduce multifunctionality, to apply hard and soft polymers, and differently coloured polymers, for improved visibility of text or design lines, and moulding text even inside a product for improved aesthetics.