Page 42 - Plastics News April 2024

FEATURE

energy consumption, and incorporate and cooling processes, along with the landscape, enabling the production of
recycled materials into the produc- implementation of advanced control intricate and high-quality plastic parts
tion process. systems, helps reduce overall energy across various industries. From auto-
Recycled Materials: consumption during production. motive components to medical de-

The integration of recycled plastics Waste Reduction: vices, plastic injections have become
synonymous with efficiency, preci-
into the injection molding process is The precise nature of plastic injection sion, and innovation. As the industry
a significant step toward sustainability. molding minimizes material waste continues to evolve, advancements
By reusing post-consumer or post- during the manufacturing process. in technology and a growing com-
industrial plastics, manufacturers can Additionally, advancements in mold mitment to sustainability are shaping
reduce their reliance on virgin materi- design and cooling technologies con- the future of plastic injection molding,
als, mitigating the environmental im- tribute to further reducing scrap ma- ensuring it remains a vital and respon-
pact of plastic production. terial, making the process more sus- sible player in the world of manufac-

Energy Efficiency: tainable. turing.
Modern injection molding machines Conclusion:
are designed with energy efficiency The art of plastic injection molding
in mind. The optimization of heating has transformed the manufacturing

Why is temperature control so important in injection moulding?

ichard Brown, chair of Judges De- at a predefined temperature. The forward but temperature control in
Rsign Innovation in Plastics Awards, coolant is pumped into the tool via a practice is far more complicated, and
addresses the overlooked importance temperature control unit (TCU). The there are many cooling-related chal-
of cooling systems and mould tool de- coolant that leaves the tool is key to lenges that are faced daily within the
sign in injection moulding. managing the heat transfer from the industry.
There are three key areas where tem- mould tool and is key to achieving a The cooling cycle generally is 60 to
perature control is crucial to the in- steady temperature on the cavity sur- 80% of the process and coolant flow
jection moulding process, these being faces of the mould tool. is critical to remove heat from the
the three ‘M’s’ of Material, Machine When the material is injected into the mould tool, so it is very important
and Mould. In many mould shops re- mould tool, the initial purpose of the that coolant temperature should be
duction in the effectiveness of cooling cooling system is to maintain an even controlled and monitored.
over time is overlooked all too often, temperature on the mould tool sur- Temperature impacts every step of
and only comes to realisation when face to ensure the tool does not over- the injection moulding process and
components get returned from the heat as the injected material takes temperature control is fundamental
customer for distortion or poor fit shape in the tool cavities. The excess to ensure that the moulding process is
and function issues. heat is removed to cool the mould effectively maintained at the required
The process of injection moulding tool which enables the injected mate- temperature.
relies on the activity of heat transfer. rial to harden and form the finished As soon as the material is fed into
The raw material (usually dried by component. the machine's barrel it is heated and
heat) is fed into the injection mould- The coolant exiting the mould tool mixed, so it is essential that the tem-
ing screw which mixes and heats the is directed to a chilling system to re- perature profiles of the barrel zones
material to soften it prior to feeding it move the heat from it, the coolant is are set correctly to ensure it is melted
into the mould tool. then recirculated back to the TCU and mixed without causing material

Mould tools are designed with inter- and through the mould tool again. degradation. The temperature zones
nal cooling channels through which The cooling principle explained in this of the barrel increase along the barrel
are fed a flow of circulating coolant manner seems fairly straightforward with the hottest zone being towards

44 PLASTICS NEWS April 2024