LWB STEINL VR INJECTION MOLDING MACHINES.
It is obvious that a machine with a tiebarless clamping unit is better accessible than its counterpart with a tiebar-type clamping unit. This applies in particular to parts handling and tool changes, both manually and automatically. LWB-Steinl has an exceptional position in this context, since between the machines with tiebarless C-frame clamp and the conventional tiebar machines there is a machine series with the denomination "VR-machines", that is neither of the two. Their clamping units consist of one or more portal frame modules which function as carriers and guide elements for the mold mounting platens and for applying the clamping force. The VR (vertical / frame) series is scalable over a wide range of sizes and opens up a number of efficiency advantages, as the following report documents.To get more news about 2k injection molding, you can visit asm-mold.com official website.
When a rubber processor in Southest of Europe wanted to source the most efficient production solution for the manufacture of large, flexible profile seals, several alternatives were up for discussion. The requirement was to accommodate large tools (plate size 1200 x 500 mm) with a relatively small clamping force requirement (2000 to 3000 kN) in such a way, that they could easily be accessed by an operator. All the more so as the profile seals in rectangular shape with a circumferential length of 2600 mm require manual demolding due to their size and flexibility. C-frame machines were out of the question due to the concept-specific size restriction. And a tie-bar clamping unit (VS series) turned out to be much too large as the injection molding tool with a platen size of 1200 x 500 mm would have fitted in a machine with 800 tons of clamping force (type VS 8000), by far too large for a manual demolding operation.
Completely different was the alternative based on the VR-series with tiebarless but frame-type clamping unit. Its concept offered the potential for a structural slim machine but laterally large clamping area, resulting in the type VREF 3200/1000 with 3200 kN closing force. It has a clamping force of 320 tons with a heating plate size of 1300 x 500 mm.
When specifying the machine design, a decision was made in favor of a design with two hydraulic clamping modules.
Instead of a machine housing with mechanical access doors a version with light curtains had been chosen to safeguard the work area on the front side of the machine.That enables the machine operator to work in close proximity to the tool area and to manipulate with minimally necessary reach of the hands and thus minimal back strain. In this way, the workflow can not only be made less stressful, but also faster. The good accessibility to the mold area also offers significant potential for reducing the changing times for the molds or the cavity platens.
The VR machine concept from LWB-Steinl not only offers advantages for large seal production, it also enables the cost-effective mass production of smaller to medium-sized bellows. Here, too, the VR machines, which also went to Southeast Europe, show their ergonomic advantages with their slim design and light barrier-monitored access protection.
The basis for this is a tool concept with an interchangeable core system enables parts to be demolded outside of the injection molding tool parallel to the injection and vulcanization cycle. Its essential component is a swiveling core support bar, each with opposing pairs of mold cores. Simultaneously with the opening stroke of the tool, the core bar is raised so far that it can then be rotated 180 degrees by the machine operator. As a result, the rubber bellows produced come to lie outside the injection mold for demolding, while the empty mold cores are simultaneously in the cavities. After the mold has been closed again, the operator releases the rubber bellows from the cores with the help of compressed air in parallel to the next injection cycle. In the project shown, the machine capacity of the VREF 320/1000 (3200 kN clamping force) used for this purpose is fully used with a 12-cavity mold. This not only affects the space and injection capacity, but also the cycle time potential, because the 12 bellows can be demolded and processed without having to wait for machine times.