A new concept for ultrasonic flow enhancement in injection moulding, to eliminate polymer leakage problems

The
EU polymer processing industry continues to contract, with companies struggling to
remain competitive. Whilst energy cost reductions would be welcomed, cycle time and
component thickness are key drivers of financial performance, with parts costed as a function
of cycle time & machine hourly rate.
Our idea is to apply ultrasonic energy into the molten polymer just before it enters the cavity.
This can yield as much as 60% reduction in melt viscosity, enabling a significant reduction in
equivalent melt temperature, thus saving both heating & cooling energy.
Our goal is to establish a clear ‘proof of concept’ for a novel transducer/sonotrode/melt
chamber design that eliminates the need for sealing, and thus eliminates the problems of
molten polymer leakage & injection pressure drop. The benefits of this are numerous. Melt
temperatures could be maintained and the lower viscosity used to enable easier filling of
existing parts or design of thinner-walled parts with corresponding reductions in cooling
times. Alternatively, the melt temperature could be reduced significantly, while still being
able to fill the same mould (due to the reduced viscosity) but with significantly lower
embodied heat the cooling time can be reduced substantially.
This technology could enable UK moulders to increase productivity and competitiveness,
regain market share and capitalise on new business opportunities. Existing parts can be cooled
much quicker; have improved mechanical properties, and potentially lower internal stress and
reduce tendency to warp. New design capability for thinner, higher aspect ratio parts would
also be possible