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Latest presses target thin-wall applications

Issue: January 2018

Netstal Maschinen AG, Näfels, Switzerland, has expanded its Elios line of injection presses aimed at thin-wall packaging applications.

Elios presses are designed to use a wide range of in-mold labeling options, making them ideal for thin-wall molding.

The Elios 4500 with 505 tons of clamping force and the 618-ton Elios 5500 join the Elios 6500 and 7500 models introduced at the K show in 2016. The two new machines with lower clamping forces and smaller injection units debuted at Fakuma in October.

All four machines in the series have electrical clamping units. The 4500 and 5500 designations represent the clamping forces in kilonewtons.

The Elios 4500, the smallest Elios press, comes with an 803mm opening stroke and an 820mm-by-820mm tie-bar space. For comparison, the 7500, the largest Elios press, has an opening stroke of 1,000mm, tie-bar distance of 1,050mm by 1,120mm and clamping force of 843 tons.   

The Elios 4500 has a dry cycle time of 1.5 seconds. The 5500 has a dry cycle time of 1.7 seconds. “If you need the highest output and productivity, there is no alternative to the Elios,” a Netstal spokesman said. “It runs as fast as the mold allows.”

Netstal, which is part of the KraussMaffei Group, said the new 4500 and 5500 models feature excellent performance for products with large flow path/wall-thickness ratios, even with deep cavities in heavy stack molds. Flow rate ratio is often expressed as the L/T ratio. The L is the distance from the gate to the farthest point in the molding dimension and the T is the thickness of the part. The flow path is calculated to determine if molten plastic can fill the mold cavity. Flow path/wall-thickness ratios greater than 350-to-1 require high injection performance. Netstal guarantees injection rates of up to 2,200mm per second.    

Like the larger Elios machines, the two smaller models have a new, centrally aligned, five-point dual-toggle clamp designed for precise platen movement and short dry cycle times. The toggle design ensures that force goes to the center of the mold space for uniform distribution of the clamping force. This prevents deformation of the mold plate.

Thin-wall packaging

The Elios 4500 can be ordered with five different injection units and 12 screw diameters, ranging from the 1,000 injection unit with 45mm, 50mm and 55mm screws, to the 6,000 injection unit with 90mm and 100mm screws. The Elios 5500 is available with four injection units ranging from the 2,000 with screws that are 55mm, 62mm or 70mm, up to the 6,000 unit.  

In total, the four Elios presses can be ordered with 33 combinations of clamping units, injection units and screw diameters. “Depending on the customer’s application, we are able to offer the perfect combination of clamping force, injection unit and drive unit,” the spokesman said.

A generously sized mold installation space accommodates large stack molds or molds with many cavities.

Kinetic energy generated during braking is converted into hydraulic energy and stored in the electric motor of the main drive, which reduces overall energy use.

The new models use Netstal’s aXos 8 control system, which was introduced at the K show and features simplified commands. The controller is easy also to customize.

The Elios presses are designed to use a wide range of in-mold labeling options.

The ejector system employs two cylinders controlled by dynamic proportional valves. These are available in three versions, depending on how much ejector force is needed.

Netstal also said the enclosed lubrication and drive systems make the Elios series ideal for clean-room applications.

Ron Shinn, editor