New Nozzle Concept Hot runner systems: Optimised for syringe and pipette production
To meet the increasing demand for syringes and pipettes, not only since the Covid 19 pandemic, production capacities in these areas are being ramped up worldwide. Ewikon has developed two hot runner systems with optimised concepts for these applications.
For the production of syringes and pipettes, efficient, high-performance precision moulds in high-cavity design with up to 128 cavities are required. In addition to the high output needed for mass production with maximum mould availability and correspondingly minimised downtimes for routine maintenance, the requirements include high repeatability and perfect gating points. In most cases, direct side gating is the method of choice. For optimum mould performance, the selection of suitable hot runner components is just as crucial as a maintenance-optimised mould design.
With the HPS III-MH111 multi-tip nozzle, Ewikon offers a slimline solution specially designed for syringe and pipette production. Compared to conventional concepts, the mould maker has significantly more installation space available between the nozzle body and the article contour. This can be used for the integration of an optimised surrounding part cooling as well as an effective cavity venting. Both factors enable particularly efficient production thanks to reduced cycle times and improved cavity filling. The proven tip exchange technology allows for the greatest possible ease of maintenance.
The tip inserts can be replaced easily on the machine from the parting line without having to dismantle the mould. Another special feature is the two-part design of the nozzle. The main nozzle is available in different lengths for optimal adaptation to any part size. It is supplied with melt by a transfer nozzle. This nozzle is installed under the manifold and provides a leak-proof seal with the main nozzle at the face side. Due to the separation of the main nozzle and the transfer nozzle, this concept allows for particularly maintenance-friendly mould designs, which can be realised in two tailor-made versions.
Two versions of the nozzle-concept meet specific customer needs
The first version integrates all main nozzles including the complete wiring into a separate nozzle retainer plate. The contour plate is attached to this before the tip inserts are installed. If a nozzle needs to be replaced, this can be done very easily. After removing the nozzle holding plate and contour plate package and dismantling the relevant nozzle tips, the nozzle to be replaced can easily be pulled backwards out of the plate without having to dismantle the tips of the remaining nozzles. The electrical connection between the plates is simply disconnected by using a plug system.
In the second version, each main nozzle is installed in a separate, customer-made cavity block with its own cooling layout. These blocks are screwed directly to an intermediate plate using a suitable centring device. The coolant is supplied via this intermediate plate. The electrical supply is also integrated in the intermediate plate. Each cavity block is connected separately via a connector plug. In case of a necessary nozzle change or a cavity fault, the entire block is simply exchanged from the parting line. For this purpose, a certain number of ready-assembled cavity blocks including the hot runner nozzle can be kept in stock for replacement. Although this variant is particularly effective in reducing downtimes, it must be considered that all replacement cavity blocks must also be validated.
Efficient and reliable high-cavity mould designs
Both versions have already been successfully used in customer applications. Thanks to the aforementioned tip exchange technology, a simple exchange of the nozzle tips can of course be carried out at any time with minimal time expenditure — regardless of the version used. The HPS III-MH111 side injection nozzle thus represents the ideal solution for the syringe and pipette production. In combination with the fully balanced Ewikon manifold technology and precise pro Control control technology, efficient and process-reliable high-cavity mould designs can be easily realised. Furthermore, the optional use of the company’s smart Control assistance system for complete process monitoring allows the full integration of mould and hot runner into the networked injection moulding production and helps to further increase process reliability.