Page 21 - Plastics News August 2020

and staff, too, as training in data science becomes more systems with minimum seals, corrosion-resistant
relevant. Remote access or remote monitoring of materials, and optimized water pressure enable a wide
equipment, recording and archiving of machine or tool temperature window with reduced condensation, a “no
settings, order management, and FDA- or GMP- sweat” effect. With trim-in-place tooling in particular,
compliant time-stamped data sets for audit purposes are independent clamp-ring pressure and individual
some of the new functions and benefits of connected downholder cooling allow highly precise and repeatable
systems. These can be categorized as software that parts. Also Improved air-flow management, including
improves the productivity of the user. air-save technology for faster filling and venting, and
locating valves closer to the cavities, also help to
Infrared scanning of sheet, either spot-based or line-
based, has been used intermittently for at least 15 increase production speeds. Tools can be outfitted with
years, but with the arrival of improved data visualization sensors to monitor strain, pressure, temperature. The
tools, the technology is finding greater acceptance. newest tools from Germany are now being equipped with
There is, however, an alternative school of thought that user-friendly NFC or RFID tags for full life-cycle
documentation, alerting operators to maintenance
calculates plug-assist or pre-stretcher power
control—i.e., force required—with a central recording of requirements.
the material's surface temperature across the entire Integrated Decoration
sheet width. In order to keep process times constant, The use of pre-printed sheet in thermoforming has been
valve actions are monitored and, when necessary, the mastered for at least 25 years. A-B and A-B-A
process parameters will automatically adjust to configurations, hinged clamshells, and candy striping
compensate for switching time. can be run on most equipment today. Distortion printing
The vast majority of machinery today runs on servo- can be effectively modeled in computer simulation tools
driven platforms, primarily in chain indexing, press such as T-Sim before going into production, where little
movements, and part-removal systems. A servo drive more than sensor eyes are required to detect specific
generates energy during braking since it works like a areas of the sheet. Secondary processes such as labeling,
generator. Usually, this braking energy is discharged to dry-offset printing, and digital printing offer high
the surroundings as heat. Feed-back drive technology speeds, but they represent additional capital spending
means the energy generated by the brakes flows into the while increasing the system's footprint.
intermediate circuit storage (battery). The drive In-mold labeling for thermoforming offers high-quality
controllers are connected to this circuit, allowing the decoration in a modular system, reducing costs and floor
energy to be used for a different servo drive. space associated with downstream equipment.
Materials Matter: Tooling Technology A key attribute of thermoforming is the ability to use
Tool cost and turnaround time are often touted as key
benefits of the thermoforming process, in both heavy-
and thin-gauge sectors. It is still common practice for
some thermoformers to manufacture their own tooling
in-house. Before delving into actual tool technology, it is
important to note that toolmakers have benefited from
advances in CNC technology. Gone are the old manual
lathes and Bridgeport presses. American, German, and
Japanese equipment dominate the machine-tool sector.
Lights-out automation allows greater flexibility in
scheduling and reduces the need for operator oversight.
Surface finishing has been improved, adding further time
and labor savings for tool shops. From the extrusion
sector, changes in CPET and CPLA material formulations
have led to new tools that eschew oil-heated dual-stage
molds in favor of electrically heated single-stage molds.
Major developments in tooling technology can be
categorized as follows: choice of materials, air flow, and
water flow. The increased use and acceptance of
aluminum has helped to boost speeds through better
temperature management and weight reduction,
leading to faster machine movements. Cooling is up to 7x
faster with aluminum tools. The use of closed water

August 2020 19 Plastics News