Presentation script on HPM Corp.'s Next Wave injection molding
machine written by Richard Stewart
HPM'S NEWEST: THE NEXT WAVE
INJECTION MOLDING MACHINE
Hello. I'm here to introduce you to HPM's latest injection molding
system: The Next Wave™, as we call it. The system incorporates
a number of innovations that solve problems common to large two-
platen injection molding machines -- problems like platen deflection
under high clamp tonnage, long cycle times, and restricted working
space in the mold area. These are the kind of problems that have
plagued molders everywhere for years.
Production requirements for injection molding machines vary by
application and customer needs. But, universally, molders want to
increase capacity without expanding the size of their production
facilities. That's the key to staying competitive.
Throughout the industry, we are seeing molders replace older
injection presses with smaller, highly efficient machines that can
give them more flexibility and higher production capacity at lower
operating costs. HPM's line of Next Wave injection molding
machines is designed to meet these needs.
The Next Wave is based on proven hydromechanical two-platen
clamping technology developed by HPM over the past 30 years.
The system features a unique, two-piece platen that eliminates
deflection on the mold faces even under the highest clamping
The key is HPM's patented Parabolic™ platen design, which
transfers the high torque of the tiebars, acting on the corners of
the platens, to the rear of the platens. This leaves the front,
mold-mounting surfaces flat -- with zero distortion.
The parabolic design, used on both the moving and stationary
platens, decouples the core of the cast platen from the front face.
The result is a leaf-spring effect, which absorbs and manages the
clamping forces without distorting the front face of the platen.
The corners bend under full clamp tonnage, but since they are
decoupled from the front face, no distortion is exhibited in the
critical area where the mold is fitted.
Computer modeling and finite element analysis played a critical
role in the development of the parabolic platen. Using the finite
element method, forces were applied to the model, and the stress
and deflection patterns were closely examined. It was apparent
that once the core of the platen was decoupled, the deformation
occurring in the corners no longer affected the front surface. It
remained flat. Then the model was optimized by removing
material from the low stress areas of the core area and the
corners. Through many design iterations, the goal of eliminating
distortion on the front face was achieved.
Maintaining a flat mold-mounting surface eliminates flash,
premature mold wear, which shortens tool life, and other
problems that molders experience as a result of deflection. Higher
quality parts and longer tool life are important benefits of this
unique parabolic platen.
Stability and parallel platen alignment is further ensured by HPM's
patented sliding-shoe carriage that supports the moving platen.
The carrier distributes the weight of the platen on the hardened
ways of the machine frame and ensures precise parallel
movement of the clamp. None of the weight is carried by the
tiebars. Their only function is locking. That eliminates tiebar
droop or bending moment that's common in other machines.
HPM's two-piece design of the moving platen allows for flexibility
needed to reduces stresses on the structure that can promote
platen misalignment. The design eliminates the possibility of any
upward deflection in the support feet that is seen in many rigid
one-piece moving platens.
The design of the carriage ensures parallel platen alignment and
keeps the mold's center of gravity within the moveable platen,
avoiding any possibility of tipping.
Another innovation of the HPM Next Wave machines -- and one
that provides a great many advantages to injection molders -- is
the design of the tiebars: They retract with the moving platen. As
the mold opens, the four tiebars move back out of the way -- for
quicker mold changes that can be easily automated -- and fast,
easy removal of large parts.
The retracting tiebars also mean reduced robotic movements,
since lateral movements are possible owing to the increased area
of free access. The robot comes down, picks up the part, then
moves right across the machine to drop it, without having to go
up and over the tiebars. Much less complexity is required in
robotic controls and equipment.
Model designations of these hydromechanical two-platen
machines are based on clamp tonnage in US tons. They range
in size from 360 to 5000 tons. To give you an idea of some
typical specifications, let's look at the Next Wave Model 1750.
It builds 1750 tons of clamp force very quickly, for a fast dry-
cycle time of only 10.4 seconds.
The machine features a very small footprint, taking 20 to 40%
less floor space than comparable, conventional machines. Fitted
with a 409-ounce injection unit, it has:
• an overall length of 12,700 mm or about 500" to save
valuable plant floor space
• a width of 4100 mm or 161" providing ample room
in the molding area
• a height of 3020 mm or 119" for excellent overhead
clearance that allows the use of top-mounted robots
• and a weight of about 123 US tons, far less than
comparable, conventional machines.
In operation, two diagonally opposed rapid traverse cylinders
draw the moving platen to the stationary platen. Lugs on the ends
of the tiebars mate with rotating locking bushings on the
stationary platen to provide a positive lock prior to clamping.
With the tiebar lugs locked, four compact short-stroke hydraulic
clamping cylinders on the stationary platen apply tonnage very
quickly for lock-up. Locking and unlocking is efficient and sure,
and the cycle is fast and smooth.
Each clamping cylinder has a transducer that monitors pressure.
If a drop in pressure is detected, the system tries to compensate
to prevent uneven tiebar loading. If it can't compensate, the
machine will shut down and diagnose the problem.
Oil volume in the Model 1750 is just 1500 liters or 400 US
gallons, which is significantly less than comparable, conventional
hydraulic machines. That means less filtration and cooling, for
reduced operating costs and reduced oil disposal costs. The lower
volume of oil also translates to faster tonnage build-up.
The 1750 features a very wide maximum-daylight dimension of
3300 mm or 130". Platen size typically offered on that machine
is 2200 mm high by 2100 mm or 87" by 83", but we can deliver
wider platens if needed. Tiebar diameter on the 1750 is 235 mm.
Tiebar clearance is 1600 mm in height and 1400 mm vertically.
The injector stroke is 240 mm or about 9 and a half inches.
The machine has a minimum mold height of 630 mm and a
maximum of 1500 mm. Maximum mold weight is typically 35
tons, but that can be increased to 50 tons or more with
modifications to the sliding-shoe carriage.
The compact size of the machine results in a significant material
savings, too -- as much as 100,000 lbs. less material is needed
to build a Next Waver machine than a comparable hydraulic
machine. That savings allows us to price the Next Wave machines
competitively. These machines feature vastly improved energy
efficiency, less noise and lower maintenance costs compared to
a conventional toggle clamping unit with its linkage system or
a hydraulic clamping unit with the large volume of oil that has
to be pumped, filtered and cooled.
The Next Wave machines come standard with automated
lubrication for reduced maintenance and clean operation. The
proportional hydraulics are driven by a combination of fixed-
displacement and variable-volume pumps for precise supply of
oil. An energy-saving mode on the pump motors is also standard
for improved energy efficiency.
The clamping cylinders are mounted on the fixed platen for
additional maintenance advantages. That allows the hydraulic
connections to be rigidly piped and avoids the need for
"moving hoses" found on other machines. The operator also
has clear access to the nozzle for easy maintenance and to
remove purged resin at start-up. This exclusive HPM design
also provides more room behind the moving platen for the
HPM's Next Wave injection molding system features modular
construction for increased flexibility. As many as four
reciprocating injection units per camp can be accommodated.
HPM reciprocating screw injection units are available from 14
to 1325 ounces or 400 to 37,530 grams.
Multi-microprocessor technology provides complete process
control and includes parallel processing for quick start-ups,
easy-to-use diagnostics, and onboard process monitoring.
Closed-loop control of injection speed, pack and hold pressure,
and screw back pressure is standard on the machines, making
The Next Wave machines are flexible enough to handle a
full range of process technologies, including gas-assistance
injection molding, relaxed molding and multi-color, multi-
component injection molding, to name but a few specialized
We think the HPM Next Wave system provides an excellent
solution for molders who need high performance and the ability
to produce larger parts from a more compact unit. From its
unique clamping system, with retracting tiebars that move freely
with the moving platen to its patented parabolic platen and sliding
shoe designs -- these and a host of other features provide
important production benefits that can help improve a molder's
It has taken HPM more than 30 years to bring hydromechanical
two-platen clamping to this level of efficiency -- with innovations
that no other manufacturer of injection molding equipment can
claim. That's why we're so proud of this product line.
Can I answer any questions?