Injection-compression molding in a stack mold with IML decoration

Netstal presented injection-compression molding in a stack mold at K 2016 in Düsseldorf. Supermarket-suitable margarine packaging with IML decoration was produced on an ELION 2800-2000. This technology, introduced by Netstal as a global innovation in 2015, is increasingly establishing itself on the market.

Injection-compression molding in a stack mold on an ELION 2800-2000

The 15oz (425g) margarine container with IML decoration is manufactured using an injection-compression process in a 4+4 stack mold.

At K 2016, Netstal demonstrated the ICM technology by means of 15oz (425g) polypropylene margarine packaging. The container merely weighs 10.7 grams and is manufactured on an ELION 2800-2000 with a 4+4 stack mold from Plastisud. The cycle time was 4.9 seconds. The clever automation solution from Machines Pagès took care of removal and insertion of the in-mold labels. Also included: a highly dynamic side entry, smart cameras for quality control and a quick delta robot for the package-based stacking of finished packaging. "After the initial introduction at Fakuma 2015, the interest of our customer in this new technology was very positive. Since the first systems have been producing with a high level of process reliability for about two years, the process has successfully demonstrated its suitability for series production," said Markus Dal Pian, Netstal's Vice President Sales & Marketing.

Only at Netstal: Supermarket-suitable food packaging with IML decoration

The ELION 2800-2000 will be the only machine at K 2016 that will produce IML decorated, supermarket-suitable packaging using the injection-compression process

When it comes to this technology, working together with Netstal as an innovation leader is particularly worth it for users, which the application at K 2016 highlighted. For example, the ELION 2800-2000 was the only ICM machine at K 2016 for the production of supermarket-suitable margarine containers with IML decoration. "And Netstal still has not tapped into its full potential by a long shot. Right now, we can implement much thinner wall thicknesses and quicker cycle times with injection-compression molding. However, comprehensive consumer tests have shown that consumers would hardly accept thin packaging and would switch to conventional products," Dal Pian notes. Therefore, a thicker wall, which was widely accepted by consumers, was chosen for the series production of a comparable margarine container. "For this reason, the market cannot exploit the entire economic savings potential of extremely thin-walled food packaging," Dal Pian adds.

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

With its leading injection molding technology, Netstal stands ready for future developments with even thinner wall thicknesses, shorter cycle times and the accompanying expected profitability for the consumer. The machine and its controls must meet very high quality requirements in order to use ICM successfully. Because corrections of the filling via hold pressure are not possible, extremely high demands on the metering accuracy result. For the perfect distribution of the melt in the injection-compression process, a clamping unit is required that operates in a very dynamic and highly precise manner. A prerequisite for the compression of the material is a fast injection performance with speeds above 800mm/s. The precise interplay between injection unit and clamping unit makes optimal repeatability possible. The injection process, which takes place when when the clamping unit is in the open state, places particularly high demands on the plate parallelism and design of the toggle lever. High-performance injection molding machines from Netstal move at the required technological level and are particularly well-suited for use in the injection-compression process.