Food & Drink Process & Packaging Issue 23 2019 | Page 21

to enhance their green credentials, being able to reduce the wall thickness of packaging by up to 25% is a significant advantage. How is injection compression moulding different to conventional injection moulding? It’s all linked to the closure mechanism Fill time for injection compression These usually perform a dual purpose, and the consequent clamping pressure moulding when operating at maximum automating the placement of labels applied within the machine, which helps speed is 0.2 seconds, with a total cycle into the mould and taking packaging to reduce shrinkage and ensure even time of around 3.3 seconds, depending on components out of the mould and distribution of the plasticised material in the application. stacking them. the cavity. Are there other environmental benefits? In conventional thin wall injection moulding, faster filling and higher pressures are required to drive molten plastic material into thinner cavities to prevent it freezing off between shots. It would be extremely challenging to repeatedly accomplish a 0.35mm wall thickness using this method. During injection compression moulding, plasticised material is introduced into the cavity prior to complete locking of the mould. The machine closing movement aids distribution of plasticised material in the cavity. Yes, switching to injection compression moulding can deliver savings on energy consumption as a result of the significantly lower clamp force pressure. Additionally, because less clamp force is required, thin wall packaging manufacturers can opt for a smaller machine with reduced tonnage and a smaller footprint. Being a hybrid machine means that speed and precision are not compromised on the El-Exis SP range. This is all due to the servo-driven hydraulic clamp unit, engineered to execute precise movements. For This injection compression reduces high-volume thin wall packaging the injection pressure and the required manufacturers, these enhancements clamping force, and this consequently aid company profitability and deliver removes the internal stresses from the both the capacity and flexibility to meet product, resulting in less warping due to future growth demands. Due to speed shrinkage. of production, most systems integrate Sumitomo Demag uk.sumitomo-shi-demag.eu robotics. FDPP - www.fdpp.co.uk 21