Ultra-fast cycling molds for plastic processing
The TachythermTM mold making process
The TachythermTM
mold making process was conceived by inventor and company founder Robert Szokolay
in 2005. It was intended as a means of creating fast-cycling molds for the
plastics industry.
It begins with
electroforming the mold cavity walls and parting line surface in nickel or a
nickel alloy. Those not familiar with electroforming are directed here
for more information on this process. The electroformed nickel shell is backed
by a somewhat thicker layer of pure copper, also electrodeposited, atop the
nickel. Because the nickel and (especially) the copper are more thermally
conductive than conventional tool steels, this nickel-copper composite has a
thermal conductivity approximately eight times that of a comparable thickness
of tool steel. Using a long-established but little-known trick, the electroform is used as an EDM electrode to erode a
closely conforming pocket into a block of conventional tool steel. At the interface between the tool steel and
the copper, the optimized cooling circuit is milled, or otherwise
conventionally machined, into the tool steel. The electroform is then sealed to
the tool steel blank, through a means appropriate to the temperature regime the
mold will see in service, and the sealed assembly is then brought to finished
dimensions as one piece, to complete the mold plate or cavity insert. See
illustrations below.
This process accomplishes
several things. First, by creating the mold cavity with nickel and copper, the
electroformed shell is essentially a high thermal conductivity envelope
comprising the mold cavity. Secondly, because the copper of the electroform
serves as one of the walls of the cooling circuit, it is in direct contact with
the water flowing through the cooling circuit, virtually sucking heat from the
cavity walls. Thirdly, because the electroformed shell corresponds to the shape
of the mold cavity, the channels of the cooling circuit are automatically
conformal to the cavity shape, despite the complexity of the part being molded.
The high conductivity envelope around the cavity conducts thermal energy from
the resin to the coolant very efficiently. This synergistic combination of
judiciously selected materials and unconventional assembly makes molds produced
by the TachythermTM process
thermodynamically superior to other molds on the market (consider that the tool
steel used in this system is a relative insulator, whereas in conventional molds
it is the primary heat conductor). Because cooling is both faster and more
uniform in a TachythermTM mold, both cycle
time and part distortion are reduced.
A TachythermTM
mold makes a better part, faster, and with less energy. That’s how a TachythermTM mold saves you money.