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

欧盟聚合物加工业继续收缩，企业努力保持竞争力。虽然能源成本的降低是受欢迎的，但周期时间和部件厚度是财务业绩的关键驱动因素，部件成本是周期时间和机器每小时速率的函数。我们的想法是在熔体进入空腔之前将超声波能量应用到熔体中。这可以使熔体粘度降低高达60%，使熔体温度显著降低，从而节省加热和冷却能量。我们的目标是为新型换能器/声电极/熔室设计建立一个明确的概念证明，该设计消除了密封的需要，从而消除了熔融聚合物泄漏和注射压降的问题。这样做的好处有很多。熔体温度可以保持不变，使用较低的粘度可以更容易地填充现有零件或设计更薄的零件，从而相应地减少冷却时间。或者，熔体温度可以显著降低，同时仍然能够填充相同的模具(由于降低了粘度)，但由于隐含热量显著降低，冷却时间可以大幅缩短。这项技术可以使英国模具制造商提高生产率和竞争力，重新获得市场份额，并抓住新的商业机会。现有的零件可以更快地冷却；具有更好的机械性能，潜在地降低了内部应力，减少了翘曲的倾向。更薄、更高纵横比零件的新设计能力也将成为可能

TheEU polymer processing industry continues to contract, with companies struggling toremain competitive. Whilst energy cost reductions would be welcomed, cycle time andcomponent thickness are key drivers of financial performance, with parts costed as a functionof 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 inequivalent melt temperature, thus saving both heating & cooling energy.Our goal is to establish a clear ‘proof of concept’ for a novel transducer/sonotrode/meltchamber design that eliminates the need for sealing, and thus eliminates the problems ofmolten polymer leakage & injection pressure drop. The benefits of this are numerous. Melttemperatures could be maintained and the lower viscosity used to enable easier filling ofexisting parts or design of thinner-walled parts with corresponding reductions in coolingtimes. Alternatively, the melt temperature could be reduced significantly, while still beingable to fill the same mould (due to the reduced viscosity) but with significantly lowerembodied 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 cooledmuch quicker; have improved mechanical properties, and potentially lower internal stress andreduce tendency to warp. New design capability for thinner, higher aspect ratio parts wouldalso be possible