Netstal is establishing ICM technology in the thin-wall packaging market

The margarine container produced in the IML process weighs just 10.7 g and will be produced live at K 2016.

Netstal thinks well beyond the machine and consistently continues to develop application processes so that customers can produce even more successfully. Through injection-compression molding in a stack mold, a technology developed by Netstal together with its system partners, a unit cost reduction of up to 10 percent can be realized with a simultaneous increase in parts quality. Netstal will present the innovative ICM technology in use at K 2016 in Düsseldorf.

A success story: Injection-compression molding in a stack mold is becoming increasingly established in the packaging market

At K 2016, Netstal will demonstrate the ICM technology by means of a 15oz (425g) margarine packaging made of PP. The container that weighs just 10.7 grams is produced with 4+4 cavities and a cycle time of 5 seconds on an ELION 2800-2000. Added to this is an ingenious automation solution for removing and inserting the In-Mold-Label (IML). The reactions of the expert public and the interest in the new technology have been positive in all respects. After the first systems were produced over a year ago with a high level of process reliability, the process has successfully demonstrated its suitability for series production.

Less material, lower unit costs: Netstal consistently further develops application technologies

The use of a stack mold leads to a significant increase in productivity (image source: Plastisud).

The requirements in regard to performance and quality on a production system are becoming increasingly more complex, especially in the highly competitive market for thin-wall packaging solutions. For other manufacturers of injection molding technology, this fact may be a risk factor that is difficult to calculate. In contrast, for Netstal it opens up tremendous opportunities for the further development of existing markets. "As the technology driver in the injection molding industry, Netstal has long thought well beyond the machines. The question always arises as to how we can further optimize maximum performance, quality and efficiency to the benefit of our customers,” said Markus Dal Pian, Netstal's Vice President of Marketing & Sales and Head of the Packaging Business Unit. “In the end, the customer expects outstanding quality of the produced parts, lowest possible unit costs and optimized overall operating costs of the system,” added Dal Pian.

In the sample production of a yogurt container, the purchasing price of the injection molding machine has an impact of just 4 percent on the calculation of the unit costs. At around 60 percent, however, the material had an enormous impact on the costs per produced unit. If an IML system is added, the machine component drops even further to merely 3 percent. “Against this background, there is only one logical consequence for us as the innovation leader and provider of premium injection molding machines: we have to further develop existing application technologies with the aim of continued increases in efficiency,” said Dal Pian.

Greater efficiency, higher quality: Use of ICM technology makes Netstal users even more successful

A modified ELION 2800-2000 is used for injection-compression molding in the stack mold.

It was therefore also no coincidence that, of all system providers, Netstal – together with its system partners – presented the highly efficient injection-compression molding technology in a stack mold a few months ago. The injection-compression process is different from conventional injection molding due to the resulting material shrinkage while the melt is cooling in the cavity, also referred to as the "shrinking effect". In conventional injection molding, this is carried out during the hold pressure phase by "pressing in" additional material. Conversely, during the ICM procedure, the "shrinking effect" is compensated by the actual compression process, where material savings of up to 20 percent are realized. Due to the incredibly fast injection times, the filling of the cavities is lightning quick yet extremely even. The reduced pressure means unwanted stresses in the product are avoided. In comparison to conventional injection molding, the pressure distribution in the cavity is extremely uniform which leads to a noticeable reduction in distortion. An improvement in filling behavior with very high flow path/wall thickness ratio is also made possible. In summary, the ICM procedure provides significant savings in cycle times as well as material and energy consumption, and increases the quality of produced packaging at the same time. Using a stack mold significantly increases the level of output.

In the comparative calculation, the unit costs can be reduced by up to 10 percent with this process. Through the additional use of an IML system, the packaging manufacturer is given absolute flexibility in regard to shape, appearance and decoration of the produced part. "With this technology, we are dealing our customers the best possible hand for generating competitive advantages and becoming even more successful,” maintained Markus Dal Pian.

Use of ICM: High demands on injection molding machine and process control 

The machine and its controls must meet very high quality requirements in order to use ICM successfully. For this reason, high-performance injection molding machines from Netstal are optimally suited for the application of the injection compression process. Because corrections of the filling via hold pressure are not possible, extremely high demands on the metering accuracy result. The fundamental requirement for the perfect distribution of the melt in the ICM procedure is an extremely dynamic and precise working clamping unit. To make compression of the material possible, an ultra-fast injection performance (>800 mm/s) is necessary. To achieve the most exact reproducibility, a highly precise and synchronous interaction of the injection unit and clamping unit is imperative. The injection when the clamping unit is in the open state places particularly high demands on the plate parallelism and design of the toggle lever.