High and medium consistency screening
Broke screening, thick stock screening, and protection screening before refining
Maximum cleanliness with minimum costs
Small debris in the approach system can cause quality problems like coating streaks or other visual defects and production problems such as web breaks downtime. Thick stock screening removes impurities before they can enter the paper machine approach system. With high-consistency screening, all the stock components entering the machine chest are screened with narrow slots of 0.15–0.25 mm.
Thick stock screening and broke screening benefits
Thick stock screening applications provide many advantages
- Screening with narrow slots in high consistency area reduces the system and pumping volumes.
- Removing the debris and impurities with efficient thick stock screening leads to considerable cost savings in headbox screening baskets.
- Narrow slots allow the highest screening efficiency.
- Flexible basket/rotor combinations allow easy and quick adaptations for all the different raw materials and applications.
- Optimized rotor dilution options and intermittent rejecting in the tailing screen allow high yield and lowest good fiber losses.
Protection screen benefits
Screening instead of high density cleaners
- Screen cylinders with 4–5 mm holes are an efficient method to stop the bale wires, stones, and coarse debris destroying expensive refiner plates.
- High-consistency screening with consistencies up to 5% allows the optimum process conditions for LC refining.
- Intermittent reject removal leads to high yield and minimum good fiber loss.
ANDRITZ stock preparation screens
- ModuScreen CP: protection screen before refining for separation efficiency at high consistencies
- ModuScreen C&F: combined coarse and fine screening with high screening efficiency and low wear
- ModuScreen A and ModuScreen F: thick stock and broke screening applications with high reliability and flexibility for all applications