Skip to main content

In-Mould Labelling used for the first time on cylindrical parts

Satisfying an order from a Polish customer, the Swiss company Netstal-Maschinen AG created for the first time an in-mould labelling (IML) system for silicone cartridges. The cylindrical geometry of the product presented a major challenge as regards the layout of the system components and the process parameters. In their search for a highly competent supplier of IML systems, Messrs Plastsystem domiciled in Glogow Malopolski, Poland, came across Netstal.

cartridge

The degree of novelty in the planned IML application called for an exact definition of the production process, which is why the process sequences and parameters were developed in cooperation with the packaging specialists of Netstal. Since the market didn't offer any IML solutions for cylindrical mouldings so far, it was particularly important to find the right partners for this production system. Eventually the mouldmaking company Otto Hofstetter AG and Beck Automation, manufacturers of removal devices, both domiciled in Switzerland like Netstal, were selected to realize this project.

The demands imposed on the production system are very high. A big challenge, in particular, is the length compensation of the film which is stretched by up to 3-5 mm on injection of the high-viscosity HDPE, with direct effects on the suface quality of the cartridge. To come to grips with this decisive sequence of the process, dynamic and perfectly reproducible filling of the cavity is essential because the film's stretching is defined by the advancing speed of the melt.

OLYMPUS DIGITAL CAMERA

Apart from the exact layout of the injection mould, the process and reproduction accuracy of the moulding machine play an important role. Machine capability, the dynamic and accurate injection as well as the precise positioning of the mould in relation to the film insertion point have a direct influence on the quality of the cartridges and the availability of the system. As usual, the film is wrapped onto a dummy in a pre-shaping station outside the machine. Unlike in conventional systems, however, the film is not statically charged, otherwise it might cling to the core, in which case it would be back-moulded. Instead, the film is mechanically passed from a sleeve to the cavity and centered there after the cartridges from the previous shot have been ejected by „falling freely“. With 8 cavities and a cycle time of 12s, 2400 cartridges are moulded per hour.

Considering that no downtimes arise for film changes and the cartridges are available for direct onward processing, a further cost saving thanks to reduced stocks is another important aspect of this highly efficient system solution. The application of latest project planning methods and the close cooperation of all system partners throughout the project under the central coordination of Netstal meant that the production system was punctually commissioned and accepted by the customer at the Netstal HQ in Näfels at the promised time. This system is suitable for the production of cartridges or tablet tubes as well as tubes by the in-mould labelling process. Like cartridges, tablet tubes can be passed on for direct further processing. In another process step the tube bodies moulded as cylindrical parts of different lengths and diameters are provided with the closure, filled and sealed. Netstal and their system partners have succeeded in integrating a highly flexible and efficient process for cylindrical products in a system and in operating this in an industrial production environment.

Source: www.netstal.com

Comments