Injection molded plastic parts are now being manufactured with functionalities previously only available from assembled components. Conventional hinges, for example, include three or more individual parts. If a single multi-component part can provide the same functionality as a plastic hinge with eight parts, it will reduce costs in material, logistics, assembly, and additional quality monitoring. At K 2007 Ferromatik Milacron used a K-TEC 450 ETW with a stack-turning mold to demonstrate the production of mechanically functional parts made of multiple materials on an injection molding machine.

The part itself looks modest enough: a toilet seat hinge made entirely of plastic. But where is the hinge? Generally a toilet seat is attached to the bowl with two hinges, each consisting of several parts. The flexible part offers the same functionality as the two hinges and replaces eight single parts into the bargain. The secret is a combination of stiff PP material with a flexible TPE component. The manufacturer calls it a “small revolution”, and they should know: Bemis is one of the largest makers of toilet seats in the world. “It’s just a question of part design and the right production technique,” said Winfried Stöcklin, General Manager of the K-TEC Business Unit and part of the team who found the perfect machine for the task: the K-TEC 450 ETW.

Plenty of Room for Special Molding Technologies

Under the banner of “Highly Integrated Functional Parts,” a K-TEC 450 ETW with a clamping force of 4,500 kN will demonstrate exactly that. The key is the use of a large mold and special molding technologies. The exhibit will feature a 6+6+6+6-cavity cube mold by Foboha with a turning diameter of 1,800 mm. The K-TEC 450 ETW has a standard tie-bar spacing of 1,000 x 1,000 mm and a tie-bar extension of 1,000 mm. Ferromatik Milacron offers tie-bar extensions of 400, 1,000, and 1,800 mm with the K-TEC machines. This ensures the space requirements for implementing technologies such as twin-cube molds. With a mold weight of approximately 12 tons, the rotation moment of the cube is considerable. The accumulator-driven hydraulics accomplish the 90-degree turns in just 1.5 seconds thanks to the exceptionally stiff construction of the machine base.

Connection Guaranteed – Centralized Hydraulic, Water, and Air Supply

The K-TEC 450 ETW is able to support the complexity of the cube mold, including multiple core pull circuits, pneumatic circuits and cooling circuits. “One of the strengths of the K-TEC series is that these machines are designed to work with complex mold technologies. Since advanced technologies are the norm here, complicated retrofits – and all the problems and compromises that come with that – are simply not necessary”, explains Winfried Stöcklin. The intelligent accumulator hydraulics plays an important role, easily accommodating parallel movements of the machine axes along with the mold movements.

The Bottom Line: Special Technologies Save Money

Dramatically shorter cycle times prove that it is worth the effort. Of course, stack turning mold technology in itself does not reduce unproductive cooling and part-removal times. However, as these steps occur simultaneously alongside productive injection cycles, the machine’s overall cycle time is employed more efficiently making the application significantly more economical than conventional solutions. But this only works if the machine can provide the necessary performance and added functionality. The K-TEC 450 ETW includes a powerful injection unit (international size 4,400) and a Meltstar screw with High-Output-Performance. The second injection unit travels on the moving mold platen and therefore does not require an additional base and the related additional floor space. The same thing is true of the part-removal robot, which is mounted on the fixed platen.

The clamping unit utilizes a three-platen design with centrally applied clamping force. This construction ensures that force is more evenly applied than with conventional designs. That translates into greater process reliability and increased mold life. The proven technology of the K-TEC series, together with a decade of experience with rotating mold technologies, ensures superior part quality.

Visualizing Special Functions in the Machine Controls

Special functions can be integrated into the machine controls with the K-TEC 450 ETW’s MOSAIC control panel. This ergonomic touch screen operator panel provides controls for the cube mold and offers a visual representation of mold operations with on-screen icons for accessing the various mold functions. Thanks to this software solution, even the most complicated mold technologies can be guided intuitively and simply via the MOSAIC control panel.

Integration in the Machine – Integration in the Part

“Integration is the key”, suggests Winfried Stöcklin. “If you are able to combine useful functions and special molding technologies seamlessly within the injection molding process, you can manufacture parts with exceptional functionality – at very attractive prices.”