Injection-compression molding in a stack mold

Netstal has been innovating in a way that it has been able to demonstrate how its breakthrough technology can help improve production efficiency and quailty. At the K 2016, the company demonstrated its ICM technology by means of 15oz (425g) polypropylene margarine packaging. The container merely weighs 10.7 grams and was manufactured on an ELION 2800-2000 with a 4+4 stack mold from Plastisud. The cycle time is 4.9 seconds. 

 

The clever automation solution from Machines Pagès took care of removal and insertion of the in-mold labels, which are being provided by Coveris. 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. According to Markus Dal Pian, Netstal's Vice President Sales & Marketing, after the initial introduction at Fakuma 2015, the interest of 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.  

 

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. The technology 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, Mr. Dal Pian added.  

 

 

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.

 

 

 

In the same exhibition, StackTeck Systems Ltd., a global manufacturer of multi-cavity, high-volume production molds for packaging, closures, personal care and medical products, also ran a 2×24 stack mold in the new ELIOS 7500 high performance injection molding machine. 

 

Netstal’s new generation ELIOS machine is the fastest dry cycle in its size class, due to a newly developed clamping unit. This machine has been designed to meet the rigorous demands of the thinwall packaging market. With a cycle time of 4 seconds, more than 43,000 round lids with a part weight of 2.8 grams will be produced per hour using StackTeck’s high precision 2×24 lid mold.