Thermal Cleaning Technology For Liquid Crystal Polymer (LCP). SCHWING Technologies GmbH Designated A New HT Model To Its InnovaClean Systems For This Application

In early 2017, the systems manufacturer SCHWING Technologies GmbH, based in the Lower Rhine region of Germany, extended its model series of thermal fluidized bed cleaning systems for tools and machine parts. This new model called “InnovaClean INB-HT” is a compact, environmentally friendly and easy-to-operate system. This new model now removes not only all polymers and halogenated materials, such as PVC or PTFE, but also high-temperature polymers such as liquid crystal polymers (LCP). It is equipped with a new heating system, a redesigned heating regulation, and a new, intuitively operated touch panel. The system is now optimized to permit temperatures of up to 620 degrees Celsius. Previously, maximum cleaning temperatures of only 520 degrees Celsius were achievable. With this enhanced fluidized bed system, Schwing now provides a perfect solution for producers of high-temperature and high-performance polymers such as LCP, PEI, PPS, PBI, various flouropolymers or PI. Thomas Schwing, managing director of SCHWING Technologies GmbH stated, “We guarantee that our InnovaClean systems are also capable of reliably removing temperature-resistant liquid crystal polymers of up to around 580 degrees Celsius from metal parts.” The company has installed the InnovaClean 2448-INB-HT model at its site in Neukirschen-Vluyn for customer trials.

New components
What’s new? InnovaClean models combine a new heating system, a newly redesigned heating regulator and a new, intuitively operating touch panel. Over recent months, the Schwing development team headed by engineer Axel Sokol has been working on optimizing the thermal cleaning systems so that contaminated metal tools and parts can undergo heating up to 620 degrees Celsius. As Axel Sokol, Schwing's technical director, explains, “The temperature increase is achieved by using a new heating system which has already been successfully tested in fluidized bed heat treatment, and guarantees precision temperature regulation.” Heating regulation has also been improved using a PLC with self-optimization functions. A 10-inch, new touch panel is larger and easier to operate than its predecessor. Its operation is intuitive and self-explanatory and it incorporates easy to use communications right through to email messaging. A simple OPC interface also ensures reliable data connections.

Benefits for system operators
The system cleans at high speed in a single process, is residue-free and requires no chemical supplements. Even tool assemblies can be cleaned flexibly and safely. Furthermore, Schwing guarantees an effective and environmentally friendly removal of all plastics, extends tool life and helps reduce machine downtimes. “We keep a steady eye on the market,” explains Udo Heffungs, sales manager at Schwing. “We are in continual dialogue with customers and aim to anticipate their wishes. LPC parts production is gaining in importance and machines and tools are being adapted to meet the demand. With our new system, we’re responding to emerging cleaning needs, especially in injection molding.”

InnovaClean INB-HT fluidized bed technology
The fluidized bed system's precision-controlled cleaning process utilizes the material and heat transfer of fluidized aluminum oxide. In simple terms, InnovaClean INB-HT consists of a cleaning chamber, waste air purification and the heating system. By means of compressed air, the oxide content of the chamber is raised slightly and then fully blown through so that it acts as a fluid. The heating process provides regulated temperature control in the chamber which, depending upon the material, can reach 620 degrees Celsius.

The contaminated tool is immersed in the fluidized bed using a special loading basket. The fluidized oxide ensures that heat is evenly and non-abrasively dispersed and simultaneously decomposes the polymers adhering to the tool all while oxidizing the remaining carbon to leave the tool free of residues. The parts are thereby cleansed of carbon and plastic with no mechanical or thermal deterioration and at polymer-dependent temperatures of up to 620 degrees Celsius.

Within just one to two hours, the system is capable of the residue-free carbonizing of any polymer, e.g. from injection nozzles and die disks. At slightly longer cleaning times, it can remove plastics from spin nozzles and assembled spin packs, static mixers, assembled pumps, back-flow preventers, hot runner components and many other parts. InnovaClean INB-HT functions without any waste water and refuse. The generated carbonization gases are cleaned with an integrated thermal afterburner which can be optionally delivered with a waste-air washer for pyrolysis gases from PVC and PTFE.