The plasticising unit has tremendous influence on the quality and performance of the injection moulding machine. To meet the customers' individual requirements in an even more targeted way, injection moulding machine manufacturer ENGEL AUSTRIA has revised and extended its portfolio of plasticising screws. New items in the product range include the Universal Automotive Screw G18 (UAS), which guarantees excellent plasticising performance across a wide range of materials, and the Mixing Barrier Screw G16S (MBS), which achieves an extremely high level of homogeneity in dyeing with master batches in high-performance applications.
High throughput with low shear stress
he UAS is geared for the requirements of the automotive industry, but also boosts the plasticising efficiency and quality in other areas, especially in technical injection moulding.
Manufacturing automotive components, especially large components, demands a screw design that achieves very high plasticising performance across a wide range of materials and material throughputs. Bumpers, spoilers and dash panels are often produced on the same injection moulding machine, but using materials with totally different properties. The new UAS ensures maximum flexibility across the entire range of materials, guaranteeing high productivity levels with short cycle times.
Based on scientific research and simulation models, ENGEL has developed a new screw design for these applications to support universal deployment, from standard plastics such as HDPE and PP, through glass fibre reinforced PP and PA, to shear stress sensitive PC-ABS and PC-PET blends. The result is a screw which achieves excellent plasticising performance due to its large surface area, while at the same time offering gentle homogenization of shear stress-sensitive materials with its innovative mixing head. The screw geometry, the non-return valve and the materials were optimised for a wide range of materials. To extend the service life, ENGEL now uses a totally new laser method for welding metal carbides onto the screw flights.
Thanks to its versatility and excellent abrasion resistance, the UAS substantially increases the injection moulding machine's productivity. The new screw is offered with diameters of 80 to 120 mm as standard equipment. Larger diameters are available on request.
Best mixing results in fast-running applications
When the task is producing moulded parts of many different colours, it makes sense to add colourant to the material directly on the injection moulding machine. The quality of the master batches and the screw geometry are key when it comes to achieving excellent mixing results. The new MBS is geared for these challenges. Its barrier geometry and dynamic shear mixing head were developed by ENGEL in collaboration with the Johannes Kepler University of Linz, Austria, and a customer in Germany.
Even before its market launch, the new screw demonstrated in pilot applications that it distributes the dye pigments evenly in the melt despite very high material throughputs. It meets the strict requirements of the packaging industry, and enables further cycle time reductions in many high-performance applications by separating the solids from the melt. The new laser welding method is also used in the production of MBS. The MBS is available with diameters between 35 and 90 mm.
New laser technology for a longer service life
ENGEL is dedicating an Expert Corner to the topic of plasticising systems at its trade fair stand in Düsseldorf. Both new screws are on display a the fair. Additionally, an MBS with a diameter of 90 mm, built into an ENGEL e-speed injection moulding machine, will be giving an impressive demonstration of its performance capability during the fair with the production of cartridges for the do-it-yourself market.
Developing and manufacturing screws is one of ENGEL's core competencies. Every year, the Plasticising Systems division manufactures more than 6,000 units. To double this figure by 2020, the injection moulding machine manufacturer is investing 17 million euros in additional machine tools, new heat treatment equipment and innovative machining technologies.
The new laser welding technology, which is used to armour the screw flights in the manufacture of the Universal Automotive Screw G18 and Mixing Barrier Screw G16S, allows carbides to be applied with far greater precision than legacy processes. The result is a particularly homogeneous structure, leaving the flight surfaces largely free of cracks. Homogeneity is the key to abrasion and corrosion-resistant surfaces, and thus for the long service lives of ENGEL screws.
Another benefit offered by the new laser technology is its flexibility in terms of the screw base material and the weld metal. A variety of material combinations are possible. And this too contributes towards being able to meet individual customer requirements in an even more targeted way.
