different aspects of plastics manufacturing require process heat. Heating of molds
/ platens, rolls, and machine barrels are three leading examples. This heat requirement
has frequently been met through the use of steam or circulating hot water. In
most cases, circulating fluid systems have been modular units dedicated to a particular
piece of production equipment. While generally acceptable, these systems do have
some drawbacks. Temperature control may not be uniform from machine to machine
due to differences in individual modules. On hot water systems, upper temperature
capabilities are limited. In steam systems, which can obtain higher temperatures,
is required, which can result in system leakage.
Thermal Fluid System, or CTFS, has solved many of these problems. It consists
of a burner assembly that generates heat inside a combustion chamber. Thermal
fluids - commonly oil based - are circulated around the combustion chamber, where
they are heated by conduction and then piped out to the process equipment hooked
to the system.
Both gas and
electrically heated CTFS are now commercially available.
CTFS offers the following advantages:
Flexibility (up to 650ºF)
Control (+/- 2ºF)
Costs (due to less scrap)
Costs (virtually nothing needs to be maintained except flame rod)
Productivity (due to operating temperatures)
Floor Space Availability (no more modular units)
have enjoyed wide-spread acceptance in Europe, their market acceptance in the
U.S. has been somewhat more limited. This is mainly due to the more modular nature
of the U.S. production facility, which places a premium on being able to add or
move equipment as required. Being tied to a central system can restrict this flexibility.
Heating Choices - At a Glance
They Work CTFS
operation involves either a vertical or horizontal heating unit, equipped with
a gas burner that provides heat through basic heat exchange to the thermal fluid
as it circulates in a coil. Hot gases from the flame circulate between the coils
and vessel walls, in a direction opposite that of the thermal fluid to achieve
maximum efficiency. Once the thermal fluid has been heated, it is pumped by the
main circulating pump through a central header and valve arrangement to deliver
process heat at precise temperatures to the molds, platens, rolls and machine
barrels of multiple machines that are processing thermoset materials.
this the gas CTFS consists of the following major components:
Control Valve with Actuator
- Mini Processor
Processes: Extrusion, Injection Molding, Compression Molding
Can an existing heating system be converted to a CTFS? Definitely! Passages can be created to flow thermal fluids. The advantages
of a CTFS clearly outweigh any conversion costs. The initial expenses may include
a thermal fluid heater and ancillary equipment, platen replacement or conversion,
retrofit of existing tool, central distribution system, temperature controllers
(microprocessors), valves, and actuators. The conversion has a quick payback due
to reduced energy and scrap material costs and increased productivity.