Most companies operating in the prevent it freezing off between shots. Additionally, because less clamp
competitive arena produce millions of It would be extremely challenging to force is required, thin wall packaging
packaging containers every year. Volume, repeatedly accomplish a 0.35mm wall manufacturers can opt for a smaller
raw material waste and precision are thickness using this method. machine with reduced tonnage and a
fundamental to each company’s financial
smaller footprint.
viability, with many facilities operating During injection compression moulding, 20+ machines to meet supplier demand. plasticised material is introduced into the Being a hybrid machine means that
cavity prior to complete locking of the speed and precision are not compromised
By applying injection compression mould. The machine closing movement on the El-Exis SP range. This is all due
techniques to stack moulds, packaging aids distribution of plasticised material to the servo-driven hydraulic clamp
moulders can now reduce the wall in the cavity. This injection compression unit, engineered to execute precise
thickness of containers and lids from reduces the injection pressure and movements. For high-volume thin
0.45mm to 0.35mm. This saves around the required clamping force, and this wall packaging manufacturers, these
25% in raw polypropylene materials consequently removes the internal enhancements aid company profitability
compared to the standard injection stresses from the product, resulting in and deliver both the capacity and flexibility
moulding process, while maintaining less warping due to shrinkage. to meet future growth demands.
comparable mechanical properties.
Fill time for injection compression Due to speed of production, most systems
Given the dominant role that materials moulding when operating at maximum integrate robotics. These usually perform
play in low cost, mass-produced speed is 0.2 seconds, with a total cycle a dual purpose, automating the placement
disposable food packaging containers time of around 3.3 seconds, depending on of labels into the mould and taking
and with packaging converters striving the application. packaging components out of the mould
to enhance their green credentials, being
and stacking them.
able to reduce the wall thickness of ARE THERE OTHER ENVIRONMENTAL packaging by up to 25% is a significant BENEFITS? * https://www.smitherspira.com/industry-
advantage. Yes, switching to injection compression market-reports/packaging/the-future-of-
moulding can deliver savings on rigid-plastic-packaging-to-2022
HOW IS INJECTION COMPRESSION energy consumption as a result of the
MOULDING DIFFERENT TO significantly lower clamp force pressure.
www.uk.sumitomo-shi-demag.eu
CONVENTIONAL INJECTION MOULDING?
It’s all linked to the closure mechanism
and the consequent clamping pressure
applied within the machine, which helps
to reduce shrinkage and ensure even
distribution of the plasticised material in
the cavity.
In conventional thin wall injection
moulding, faster filling and higher
pressures are required to drive molten
plastic material into thinner cavities to
FDPP - www.fdpp.co.uk 17