Big News for Precision Low Pressure Plastic Moulding

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(Ultrasion will be launching the newest version of its ground-breaking ultrasonic moulding technology at the K-Show in Dusseldorf in October, opening up the process to a wide array of OEMs across the world.)

(Barcelona, Spain, September 2016) Three years ago, Ultrasion SL, Barcelona, Spain, burst into the precision moulding sector with its revolutionary ultrasonic moulding technology. Since then, ultrasonic moulding has been used by an array of OEMs throughout Europe, the United States, and the Far East to solve problems impossible using conventional moulding technologies, and has stimulated innovation truly manufacturing parts and components previously seem as beyond the capability of moulding technology.

At this year’s K-Show being held in Dusseldorf in October, Ultrasion will launch its latest ultrasonic moulding machine. The new machine opens up an array of new possibilities, and will appeal to a wide range of manufacturers focused on precision moulding.

Enric Sirera, General Manager at Ultrasion explains the new developments. “When we launched our first ultrasonic moulding machine back in 2012, we were overwhelmed by the interest from manufacturers world-wide. The first version of the technology was focussed on micro moulding projects, being able to manufacture parts with a shot weight of 2 g and lower. It was also ideally suited to prototyping and research projects, and machines were sold extensively throughout the United States and Europe, with recent uptake in the Far East.”

“The launch of the second version of the machine is exciting for us, and for manufacturers of precision plastic parts, as the new version of the technology accommodates larger shot weights and is ideally suited to mass production. This represents a massive opportunity for plastic manufacturers, as the benefits of ultrasonic moulding can now be introduced to countless moulding projects.”

There are good reasons why manufacturers are so excited about ultrasonic moulding, with Dennis Tully, President of MTD Micromolding, Charlton, MA, USA saying that “ultrasonic molding is the most radical approach to molding in probably 100 years.”

The reason ultrasonic moulding opens up such opportunities for plastic part manufacturers, is that it overcomes problems inherent in precision moulding for decades that no other technologies can usefully address.

The technology was built from the ground up to address these fundamental issues, key among which is material degradation by dramatically reducing the thermal history of the polymer being processed.

Material degradation is a product of the residence time of melted plastic heated in advance of its injection into the mould. Residence time occurs in ALL traditional technologies that rely on screws, barrels and heater bands.

Ultrasion eliminates material degradation by removing screws, barrels, and heater bands and instead doses the precise amount of material needed per shot direct to the mould where it is melted in-situ using an ultrasonic horn (sonotrode).

The technology uses standard room temperature pellets which as they are melted and injected in one process eliminates residence time and therefore eliminates material degradation.

In addition, there is no purging necessary with the ultrasonic injection moulding machines and material wastage is reduced by up to 90% depending upon the precise nature of the application. In addition, as energy is only imparted as the sonotrode is on contact with the plastic to be melted per shot, 90% energy savings can also be achieved.

Ultrasion R&D Manager Alfonso Pascual discusses the unique nature of the process. “Plastic melted through the use of ultrasonics exhibits radically different and advantageous characteristics when compared with plastics melted through the use of traditional heater bands. Key is that ultrasonic melting reduces the viscosity of melted plastic, this being a bi-product of the ultrasonic agitation itself which increases the free volume between the molecules in the melted polymer, and the fact that the sprue concept in the Ultrasion technology means that it behaves as an energy director as well as part of the ejection system. The energy director orientates the waves in the flow direction, therefore the molten material and waves travel together toward the cavities, reducing the viscosity of the polymer.”

The high intensity mechanical vibration transmits energy directly into the polymer molecular structure resulting in a very fast and efficient melting “inside-out” rather than “outside-in” which is typically how melting occurs in injection molding via electric heaters. Reduced material viscosity also means that the moulding pressures required are significantly reduced compared to traditional micro molding technologies, which ensures that the material remains relaxed during the molding process, meaning less shear, and more conformity and uniformity in molded parts. This is especially critical for optical components where low birefringency levels must be achieved.

Sirera concludes, “Lower moulding pressures means that there can be tooling costs savings as there is less wear and tear, but more importantly means that it is possible to use delicate and precise core pins and insert configurations that would break under normal micro moulding pressures. The low moulding pressures (in addition to their importance for optical applications) also make the ultrasonic precision moulding process ideally suited to over and insert moulding applications, with success being achieved with no damage to the overmoulded parts.”

The K-Show will be the launch event for Ultrasion’s new ultrasonic moulding machine, and there will be a working machine on-site for customers to see in action. The future for plastic moulding is changing fast, and a visit to Hall 13 Booth D25 will revoloutionise the way that OEMs make plastic parts in the future.

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