SuperDebind - Binder Removal from Injection Moulded Components

General
The supercritical fluid debinding system, SuperDebind, is designed for removing binders from components produced by Powder Injection Moulding (or the related Metal Injection Moulding and Ceramics Injection Moulding). The process uses environmentally benign carbon dioxide as solvent. The unit offers full flexibility for any parameter of the operating condition that has an impact on the cleaning process. The binder removed is separated and collected for reuse or disposal. The unit is built in a compact skid mounted frame on wheels which can easily be connected to the electrical network, air supply and carbon dioxide storage. The size and weight of the unit (2600 x 800 x 2000 mm and 1400 kg) make installation easy and flexible.

Process
The cleaning process is based on dissolving binder components in supercritical carbon dioxide (scCO2) at elevated temperature and pressure. The CO2 is initially pressurised and then heated to the desired conditions before being fed to the washing chamber. After dissolving the binders the CO2 passes through a pressure release valve. The pressure of the “loaded” CO2 is reduced to 50 bar and any liquid CO2 is gasified in the evaporator/separator. The binder is collected in the bottom of the separator from where it is removed. An activated carbon filter is used to eliminate any liquid contaminants from circulating in the system. The gaseous CO2 is then liquefied in the condenser and drops into the storage tank ready to be reused.

Process Items

Washing Chamber
The unit has a washing chamber with 45 L effective volume and an inner diameter of 315 mm. It is equipped with a lifting tool to make loading and unloading easy. The washing chamber has a lid with easy to operate open-close function. Other sizes of washing chambers are available on request.

CO2 Unit
The CO2-loop consists of the main equipment as per the figure to the right. The main process parameters, temperature, pressure and washing time are controlled and can be adjusted independently for any process requirements or to tune the solvating performance of the carbon dioxide.

Instrumentation
The process is fully automated which makes operation very easy. The interface between the operator and the built-in control system consists of buttons for the main functions such as starting and stopping the washing sequence and there is a touch-screen for more detailed interaction with the control system. The progress of the washing cycle and the remaining washing time can be monitored on the screen as well. As an option the unit can be equipped with remote control and data logging.

Installation
All parts are assembled in a compact frame, complete with all piping, instrumentation and electrical wiring. The frame is covered with plate elements and all controls and gauges are located on the front panel.

Process Parameters These values are indicative representing an average process. However, other values can be obtained depending on the application.