All-electric injection molding machines gaining, key to future of molding for the packaging industry

ENGEL North America demonstrated how to use these trends to increase cost efficiency and competitiveness. Two manufacturing cells for the packaging industry were on display, demonstrating the current industry challenges: highest throughput rate at lowest unit costs on the one hand, and the efficient production of attractively decorated thin walled products on the other. Thin walled lids for newly developed ice cream containers were produced by an all electric ENGEL e motion 740H/310W/200 T US combi injection molding machine using two component injection molding and in mold labeling (IML). Once the label is inserted into the mold, the cover is injected from clear polypropylene. Immediately following, a colored edge - also from polypropylene - is added as a second shot in the same mold. In series production, the color used varies depending on the type of ice cream: a red edge for strawberry ice cream, a yellow one for banana. The two component injection molding, combined with IML, allows packaging manufacturers to easily switch from one type of ice cream to another, making it possible to produce even small batches in a highly economical way. The manufacturing cell is fully automated. The all electric ENGEL e cap 3440/460 US injection molding machine used a 96 cavity mold, with an hourly production rate of almost 130,000 HDPE water bottle caps. This output is achieved by operating at a cycle time of 2.7 seconds. Cycle times of less than 3 seconds and injection speeds of 450 mm per second can be realized. Until now, this performance class was dominated by energy intensive accumulator machines, though this will change as the high precision, low energy all electrics prove themselves. Designed to achieve maximum output and process stability, the all electric injection molding machine is able to save energy and cooling water requirements at the same time. The machine bridges this challenging gap thanks to its all electric drive technology, combined with a series of sophisticated features, such as the latest powerful, premium quality injection unit, increased ejector force and a reinforced clamping drive. Compared to a hydraulic machine, the ENGEL e cap reduces energy consumption by more than 40%. Delivering clamping force of between 100 and 420 tons, the e cap is available across a comprehensive range of sizes.

Haitian introduced a new all electric line for medical molding that is the fruition of a seven year German based development project to break into the Japanese dominated field of high tech, all electric injection molding machinery. The innovations are coming from Zhafir Plastics Machinery GmbH. Zhafir Mercury 1000 35/35 is a tiebarless, all electric machine that uses side plates rather than tiebars to create 70% more mold space, allowing use of larger tools on smaller machines. The machine design is described as 30% slimmer than previous models, boosting productivity per square foot. The toggle clamp mechanism has just two levers and a central servo direct drive. The simplified design is aimed at smoother machine operation in an effort to boost repeatability. There is no lubrication requirement. The melt quality is improved by separation of plastification from injection in a two stage injection unit. A unique rinsing process is said to eliminate melt residue. Plastification occurs immediately via a high torque motor. The injection process is controlled by a central spindle driven by a servomotor, which shortens response time and achieves speeds of up to 500 mm/sec with acceleration of over 10g. There are three screw drives and three screw diameters available for each machine size. In an interesting, energy saving feature, the central power supply to the drives and a new generation of inverters from KEB GmbH recirculates the braking energy back into the power grid. Servo motors with low inertia reduce energy consumption during heavy acceleration.

Arburg's fully electric Allrounder E machines significantly expand the fully electric machine range. These machines are primarily designed for the efficient manufacture of standard items, such as technical molded parts, making them the electric alternative to basic hydraulic machines. This new fully electric series comprises a total of four machine sizes, which can each be equipped with a variety of injection units. The spectrum ranges from the Allrounder 370 E with a clamping force of 600 kN (66 tons) and size 170 (3.7 oz) injection unit to the Allrounder 570 E with a clamping force of 2,000 kN (220 tons) and size 800 (15.3 oz) injection unit. The new electric machines provide an economical, cost effective electric solution as an alternative to basic hydraulic machines. These machines offer advantages in terms of cycle times thanks to their rapid and simultaneous execution of the most important machine movements and their potential with regard to energy efficiency. With all the fully electric Arburg machines, the high efficiency of the servo electric drives and the toggle type clamping unit ensure extremely energy efficient operation. Servo motor energy recovery during braking also has a beneficial effect on the machines' overall energy consumption. Together, these factors combine to reduce energy consumption by up to 50% compared to standard hydraulic machines.