Harper pioneered the Microline™ concept based on flexibility and versatility to change and modify equipment parameters for the needs of customers in carbon fiber research for experimentation with traditional or emerging precursors, process tweaking and development of samples for up to 1.5 tons per year. Our system accommodates line speeds ranging from 0.1 m/min to over 1 m/min and tows from 10 filaments to 48000 filaments, enabling the study of effects of various process parameters using a small amount of precursor.
Harper systems allow for maximum manipulation of key process parameters, including controlling tension after each unit operation and multiple zones of temperature control in oxidation, pre-carbonization and carbonization. Our drive systems are designed for precision control of the forces imparted to the fiber, allowing for flexibility in tow counting, loading, and drive position. This flexibility yields greater customization of oxidation, with adjustability zone by zone, pass by pass, and carbonization.
Most lab-scale testing is performed in discontinuous batch processing steps; the Harper International system provides continuous conversion of filamentary material, ideal for obtaining samples for fiber property data. We’ve designed advanced features to better assist in research goals and future scale up, such as :
- precise pressure and temperature data from every oven pass
- the ability bring up to temperature and stabilize quicker
- controls that better analyze and adjust atmosphere and off gassing conditions
- low minimum loading point to enable research on minimal filament counts
- Oxidation Oven: Up to 300°C, with multiple Zones of Control
- LT and HT Furnaces: Pre-carbonization and Carbonization: Up to 1000°C and 1600°C respectively, with multiple Zones of Control, atmospherically controlled
- UHT Furnace for Carbonization: Up to 2800° C, atmospherically controlled
- Creel: Up to (8) positions
- Drive Stands: Multiple locations throughout the system
- Pretreatment, Surface Treatment & Sizing Systems: single or multiple dip
- Control Systems: with advanced configuration for preferences regarding remote access and data historian
- Material Handling, including for emerging precursors including those requiring belt transport
Overall plant footprint for an example line as shown here is approximately 40m L x 10m W x 4m H. Start-up for Harper equipment from ambient conditions takes 8 to 12 hours. Shut down can occur in a shorter time frame. To optimize the life of the equipment and minimize thermal cycling, we recommend that the LT and HT furnaces be at idled at temperature for short downtime durations (i.e. over a weekend). This also optimizes power, when considering the requirements for heat-up. Harper’s Pulse team can recommend additional operational procedures to maximize efficiency and productivity of the line based on your unique business objectives.
Watch this video that brings to life the critical carbon fiber scale up path from small scientific research lines to full scale production, or read more about Harper’s comprehensive technology offering in carbon fiber processing no matter what stage of commercialization: