Smart Molding International 4-2021

molding technologies 35 www.smart-molding.com TPE-sections at the contact points to the metal body and at the through- holes for the windshield wipers. Only "rethinking" could lead to the desired goal 2-component automotive parts are not new for the ELDISY injection mold - ing department. Examples from previ - ous contract manufacturing include water deflectors, sill strips, joint seals or window guides. The production machines used for this purpose were or are the 2C variants of conventional horizontal injection molding machines from various manufacturers. All of them are equipped with a rotary table on the moving machine platen and in - jection by means of two injection units in piggyback arrangement through the fixed machine platen. Dr. Detlef Scharge, Eldisy's plant manager for many years but recently retired, comments: "For many years, this concept was regarded by us as the "state-of-the-art system" for multi-component injection molding. We used it consistently over a wide clamping force range. However, the larger the machines became, the more serious the system-related disadvan - tages became. In particular, the hori - zontal rotary axis, including the rotary feedthroughs for the media fed to the mold, suffered from the one-sided weight load of the injection molds hanging on the rotary tables. This re - sulted in increased maintenance and servicing costs. The hot runner design was also more restricted than desir - able with increasing mold size due to the system-related close proximity of the injection positions of the piggyback units. Therefore, the search for alter - natives had been on our agenda for some time. But the real catalyst for this was the order for the water box cover. Because of its size, we had to find a solution, as we would have needed a 16,000 kN machine to install the mold for it according to the old principle, which would have been uneconomical both for the technical reasons already mentioned and because of the invest - ment required for this." The system change takes shape This opened the door for a market research. Chance came to the res - cue, namely at the K-2019 trade show booth of the LWB-Steinl company. There, LWB had exhibited a production cell with a large rotary table clamping unit with thermoplastic injection unit. A similar layout seemed to be the alter - native ELDISY management was look - ing for. It was the starting point for the discussions. By coincidence, the LWB managers responsible for design and sales and company boss Peter Steinl were also present at this time and immediately took up the ideas of the ELDISY management and were able to sketch out a feasible machine concept together with them. Helpful was also the presentable ad - ditional reference of a large machine delivered in 2019 in the form of a pre - cision sheet metal press with a clamp - ing force of 19,000 kN with a clamping area of 2.5 x 2.5 m. Both of these things together then paved the way for a concrete proj - ect inquiry that initiated the system change in 2C-large-part production. And this despite the fact that LWB had not previously been "on the cards" as a possible supplier for plastic injection molding machines of this size. The alternative is the VR-machine- system from LWB At the end of the subsequent con - cept phase, a machine with the spe - cific type designation VR 12000 / 1097 / 220 Dual Sonder took shape. This bulky designation stands for a machine from the VR (vertical frame) series. Its clamping concept is a specific LWB de - velopment and occupies a special posi - tion between the tie-bar-less C-frame machines and the conventional tie-bar machines. The central components are portal frame modules as carriers for the mold fixing platens and the press modules for generating the clamping force. The VR series has a modular design throughout and is therefore largely freely scalable. The reason for this, and this is the great advantage of the VR system, is that the size of the clamping unit is not tied to the size of castings. Since the frame modules are Detailed view of the rotary table with the 18 t injection mold and the four pressure pad modules