Recovered Paper Fibre

Paper mills using recovered fibre spend their maintenance budget on blockages and on the things that arrive with the paper.

Interlocking and wrapping

Long fibres and sheet fragments bridge openings and wrap around shafts, screws and rollers.

• Generous cross sections and no converging corners.
• Shaft protection and anti-wrap design on every rotating element.
• Access for clearing that does not require entering the equipment.

Contamination

Plastics, wire, staples, glass and the occasional unexpected item arrive with every bale.

Magnets, eddy current separators and screening protect the pulper and the downstream equipment, and their reliability determines how often the line stops.

Fire and dust

Dry fibre and paper dust are combustible, and baled storage has a well-documented fire history.

Spark detection before filters, dust collection with explosion protection and controlled storage block sizes are the usual measures.

Moisture

Wet bales are heavy, form plugs in conveyors and support biological heating in storage.

What to establish before buying equipment

• Bale size, density and the opening method.
• Contamination profile of the supply stream.
• Moisture range on receipt.
• Fire detection and dust protection strategy for storage and handling.

Recovered fibre does not behave like a granular bulk solid at all.

The particles interlock into a mat that holds its own shape, so a bin can be full and deliver nothing. Moisture makes it worse, and stored wet fibre begins to compost, which produces heat and odour.

• Avoid deep storage; the interlocking strength grows with depth and time.
• Keep it dry, or accept that it will heat and smell.
• Expect that a plain outlet will not work and plan a mechanical discharge from the start.

Mechanical discharge and generous geometry are the whole answer.

Screws, sweeps and live bottoms move fibre; gravity does not. Clearances have to be large, because fibre packs into anything tight and wraps around anything rotating.

• Live-bottom or screw discharge, sized with torque reserve.
• Generous clearances and smooth transitions to avoid wrapping.
• Metal and contaminant separation upstream, because recovered fibre carries everything the collection system allowed.

The dust is combustible and the stored material can self-heat.

• Dust collection with explosion protection where fines accumulate.
• Temperature monitoring in significant stores; composting fibre heats slowly and deeply.
• Entry procedures assuming a depleted atmosphere and an unstable mass.