Transfer of Substrate
Classical multi-component technology generally uses turntables. Substrates are transported from one station to the next along the machine axis. This requires wide tie bar spacing and is generally done with machines with high clamping force.
Stack-turning mold technology was developed jointly by Foboha Formenbau GmbH
and Ferromatik Milacron. The transfer of the substrates is effected by
the rotation of the center block of the stack-mold around the vertical
turning unit. This turning unit has been standardized and can therefore
be used for various molds. The turning unit consists of two parts: the
lower part is positioned on rollers on the machine base and is
supported by the tie bars; the upper part is positioned directly
between the tie bars. The center block of the rotating stack mold is
mounted between the lower and upper turning units. Thus, the heavy
center block is positioned on the machine base and the exact
positioning is achieved across the four tie bars of the machine.
The drive for the turning movement is usually integrated in the lower
turning unit and can be either hydraulic or fully electric. For a 180º
movement the turning times are between 1.0 and 1.6 sec. depending on
the size and weight of the mold. The cube mold with its four identical
core sides is the logical extension of 180º stack-turning mold
technology. The cube mold has turning times of between 0.4 sec. and 0.8
sec. for each 90º movement.
Unique Benefits for the Customer
Stack-turning mold technology offers double the cavitation and
therefore double the yield with the same clamping force. Or, the same
cavitation can be had with half the clamping force for reduced cost and
space requirements. There is considerably less wear and tear on the
mold and machine because the strain is always evenly distributed,
regardless of the varying surface conditions presented between the
substrate and finished product. In addition, the cube mold offers the
possibility of simultaneously carrying out additional operations in
each free 90º position while the injection process is taking place.
Thus, the following can take place at the same time: the inlaying of
inserts or decorated film, the removal of finished mold or the testing
and additional cooling of substrates or finished parts. Thus
significant cycle time reductions can be achieved, compared with
conventional turntable technology. Part cost reductions of 25% are not
uncommon.
Since it was introduced in 1998 more than 60 systems have been
delivered which attest to its success as a unique and versatile machine
for the customer. Stack turning has taken hold in the market,
providing an economic alternative to established systems on the market.
A Solid Foundation
Stack-turning mold technology is available for the MAXIMA and K-TEC machine series. Stack-turning allows the large machines in the MAXIMA series to use multi-component technology (for the large auto parts, for example). Our applications team has the expertise and experience to advise you on how stack-turning mold technology can help you.
