Secondary Fiber PPT 210

Secondary Fiber Fibrous material that has been through the manufacturing process and is being recycled as the raw material for another manufacturing product Fibrous material that has been through the manufacturing process and is being recycled as the raw material for another manufacturing product

Recycling/Secondary Fibers

Waste Paper Collect Collect Sort Sort Classify Classify Know It’s Variables Know It’s Variables

Contaminant List by Severity Contaminant Pressure Sensitive Adhesive (Most Severe) Non-Dispersible Adhesives Non-Dispersible Varnish Coatings Electrostatic Inks Chipboard Non-Dispersible Inks Poly Coating Carbon Paper Plastic Wet Strength Papers String Unbleachable Paper Metal (Least Severe) Rating

Stickies Contaminants Chemical Composition Resins: Hot Melts: Wet Strength Resins: Latex: Polyvinyl Acetate Polyvinyl Alcohol Polystyrene (foam) PolypropylenePolyethyleneWaxesTarAsphaltPitchParezKymeneMelamineUrea SBR Rubber Vinyl Acrylics Pressure Sensitive Adhesives Other Synthetics

Coatings Contaminants Contaminants Clay Coatings Original Use Added to Give Paper & Smooth Surface Paper or Paperboard Laminates and Coatings Added to give Good Gloss and Grease Resistance; Vapor Proofness, Heat Sealing, Strength, and Special Resistance to Solvents In-Mill Processing Difficulty Disintegrates into Flakes Causing Defects in Final Product Difficult to Disperse in Pulper; Formation of Objectionable Specks or Pellets; Fouls Equipment Causes Difficulty in Deinking Wax Coatings Solvent Coatings (cellulose nitrate, vinyl)

Coatings Contaminants (cont’d) ContaminantsLatex Original Use Used as Binders and Saturants for Paper and Board Polyethylene, Polypropylene, and Polyamide Resins Applied by Extrusion Method In-Mill Processing Difficulty Difficult to Remove in Some Cases; Detrimental to Pulp Quality Does not Disintegrate During Cooking and Difibering; Detrimental to Pulp Quality Extruded Coatings

Other Contaminants Contaminants Wet Strength Polystrene Original Use Paper Treated with Resins Blocks, Beads, etc, Used in Packing In-Mill Processing Difficulty Does not Disperse in Pulper; Causes Spots in Product Difficult to Remove, Sticks to Rolls, Indents Sheet and Causes Pickscouts

RePulping of Waste Paper Continuous Pulper Continuous Pulper Ragger Ragger Clam Shell Clam Shell Detrasher Detrasher Disperger/fiberizer/Deflaker Disperger/fiberizer/Deflaker

Repulping of Waste Paper Batch Pulper Batch Pulper Dewire or Wire Removal Dewire or Wire Removal Detrasher Detrasher Heavies Screen/Cleaner Heavies Screen/Cleaner Deflaker Deflaker

Recycled Fibers

The Process Begins – Waste Paper Bales

Rejects Hylte Museum

Pulper Schematic

Variables of RePulping Stock Temp. Stock Temp. High until it affects contamination High until it affects contamination Increase fluidity Increase fluidity Consistency Consistency High with circulation High with circulation

Pulper Conditions Consistency5% Temperature50-90 o C pH Time mins Energy kwh/t BleachNone, Hypochlorite, Peroxide, Hydrosulfite

Potential Waste Paper Recovery Rates Potential Recovery Rates (50-57%) (63-70%) (15-30%) (100%) (50%) (37-50%)

Where Used Multi-ply – 75% Multi-ply – 75% Corrugated Medium Corrugated Medium Paperboard Paperboard Building Products – 10% Building Products – 10% Newsprint et al – 15% Newsprint et al – 15%

Effect of Repeated Recycling on Strength Properties of Unbleached Kraft Pulp

Effect of Recycling

Recycling Operations StepPrincipal Contaminant Functions Prepulping- Classification of Paper Sources by Grade - Quality Control of the Grades - Contaminant Removal From Papers Pulping- Wetting of Paper - Conditioning of Fiber - Conditioning of Contaminants - Removal of Large Type Contaminants Secondary Pulping- Wetting of Fiber Bundles - Conditioning of Fiber - Removal of Medium Size and Heavy Contaminants

Recycling Operations cont’d StepPrincipal Contaminant Functions Coarse Screening- Removal of Medium Size Particles Coarse Cleaning- Removal of Medium Heavy Contaminants Deinking- Ink Removal - Ash Removal - Small Heavy and Light Particles Removal Screening- Medium and Small Particle Removal

Recycling Operations cont’d StepPrincipal Contaminant Functions Cleaning: Forward- Small Heavy Particle Removal Reverse- Small Light Particle Removal Reverse- Small Light Particle Removal Color Stripping- Modification of Dyes - Lignin Conditioning - Fiber Conditioning Mechanical- To reduce the Contaminant Particle Size Usually to Below 10 Micron Dispersion- Fiber Conditioning

Recycling Operations cont’d StepPrincipal Contaminant Functions Chemical Dispersion- To Separate Fibers - To Reduce Contaminants Particle Size, Mainly Ink Particles - Fiber Conditioning Deflaking- To Separate Fiber Bundles - To Separate Particles From Fibers