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The development of a high output processing method for the extrusion of solid thermoplastic sheet and profile

Final Report Summary - FREEFLOW (The development of a high output processing method for the extrusion of solid thermoplastic sheet and profile)

The main objectives of the project 'The development of a high output processing method for the extrusion of solid thermoplastic sheet and profile' (FLOWFREE) were to:
- Develop a prototype extruder that will allow full industrial, commercial development of the process
- Develop the process on an industrial scale for SMEs with different production requirements
- Demonstrate the technical and commercial viability of the process on full industrial scale
- Carry out dissemination and training activities that allow for maximum exploitation of the technology

The project considered the use of CO2, in a supercritical state as processing aid to overcome typical high viscosity problems encountered during melt extrusion and to increase processing efficiency and reduce costs. Although CO2 is commonly used to foam polymers, the objective was to develop a new technology that enables the production of solid extrudate, with the associated benefits of reduced melt viscosity, thereby potentially allowing processing at faster output rates, lower temperatures and with reduced energy consumption.
Prototype systems were initially tested at three research partners, parameters optimised and then scaled-up and installed at four industrial locations to enable testing of the process within a production environment. IPR developed during this process was protected for future exploitation by consortium members.
Training materials, a website and a best practice guide were produced to aid dissemination of the project findings and to encourage take-up by the industry.

The objectives of the project have been reached. Patentable technology has been applied to the complete CO2 assisted extrusion process in order to achieve maximum processing benefits. Arrangements are in place to actively seek exploitation within the extrusion sector of the plastics industry.
Trials with the industrial partners within the project have shown benefits which could potentially be implemented to improve their market competitiveness.
The modifications performed at each extrusion line worked well for the extrusion process assisted with the CO2 injection.
The best results were obtained with PVC as it was easier to control foaming of the extrudate and it was possible to obtain solid profiles with the same properties as those obtained with the traditional extrusion process.
Benefits in torque reduction, output increase and energy consumption reduction were measured and contrasted during the industrial trials. These benefits were more or less important depending on the polymer to be extruded.
The use of CO2 did not affect the mechanical and thermal properties when compared with solid extrudates.