Cellulase for Paper Manufacturing and Recycling

In paper manufacture and recycling, cellulase is investigated for controlled fibre modification. The objective may be improved drainage, a change in refining demand or assistance with ink release. The treatment must preserve the fibre and sheet properties needed for the paper grade; maximum cellulose breakdown is the wrong endpoint.

What cellulase does to pulp

Cellulase hydrolyses accessible cellulose and can change the behaviour of fibre surfaces and fines. The outcome depends on furnish, previous recycling, refining history and enzyme activity profile. A change in freeness must be assessed alongside fibre loss and handsheet properties before it is counted as a process benefit.

Which product should I choose?

• Endo-cellulase is a candidate for controlled internal chain cleavage. Establish a conservative treatment window and measure strength rather than assuming selective action guarantees preservation.
• Liquid cellulase offers convenient dosing into mixed stock. Determine the effect of its complete activity profile on the furnish.
• Powder cellulase offers a dry formulation option. Prepare a consistent dispersion and check carrier effects in the mill system.
• Exo-cellulase is a specialised comparison for additional hydrolysis; it is not a default choice where retaining fibre mass and strength is central.

Put the treatment in a defined process stage

Identify a stage with measurable stock consistency, adequate mixing and controlled contact time. Compare treatment before refining with the existing process if refining demand is the target. For deinking development, assess treatment together with the actual flotation or washing step; released ink still has to be removed.

Use temperature and pH conditions supported by the selected grade and compatible with the furnish. Check exposure to oxidants, biocides and other process chemicals. Do not assume that dilution, a downstream pH change or routine drying immediately stops all activity.

A practical bench-development workflow

• Take one representative furnish sample. Measure oven-dry solids and document fibre mix, ash, fines and refining history.
• Prepare equal-consistency batches with identical mixing. Compare untreated stock with 0.5×, 1× and 2× a supplier-agreed starting dose, beginning conservatively where strength is critical.
• Use an illustrative 15, 30 and 60 minute sampling series if it fits the intended mill stage. These are screening points, not a validated optimum.
• Apply a validated stopping procedure for each comparison, or standardise the elapsed time to every subsequent test if continued activity is part of the process under study.
• Measure drainage and prepare handsheets at matched basis weight and conditioning. Include tensile and tear properties, fibre yield and fines; add brightness and residual ink measurements for deinking trials.
• Repeat the promising condition with representative process water and mill additives before moving to a pilot run.

Dose on oven-dry pulp

Report dosage as g product/tonne oven-dry pulp or another explicitly defined basis. If a selected dose is d g/tonne and the batch contains M tonnes oven-dry pulp, add d × M g. A hypothetical 100 g/tonne dose on 0.2 tonnes oven-dry pulp requires 20 g; this illustrates arithmetic only.

Calculate dry pulp from measured stock consistency. A 1,000 kg stock batch at 4% oven-dry consistency contains 40 kg, or 0.04 tonnes, dry pulp. Keep enzyme activity and assay definition with the dose record, particularly when changing preparation or supplier.

Troubleshooting

• Better drainage but weaker sheets: reduce dose or residence time and examine fibre loss and fines. Drainage alone is not an acceptance criterion.
• Little response: confirm stock mixing, enzyme survival and whether the selected activity addresses the actual bottleneck.
• Inconsistent results: control consistency, refining history, process-water chemistry and the time between dosing and testing.
• Ink release without cleaner pulp: review the removal stage and particle behaviour; cellulase treatment does not replace flotation or washing.

Scale-up and acceptance criteria

Set minimum strength and yield requirements before optimising drainage or refining. Compare refining energy at a matched finished-sheet specification, not merely after an equal number of refiner passes. Track water-loop effects and dissolved or suspended material during the pilot.

Check actual residence-time distribution and dosing response during starts, stops and throughput changes. Compare enzyme cost and any extra heating or holding with measured production benefits. Avoid assigning a percentage energy saving until the mill trial demonstrates it.

Evidence and scope

Published work on enzyme treatment of recycled kraft pulp is linked below as application context. Different furnishes and preparations require their own evaluation. This workflow is a development plan, not a guaranteed drainage, strength or energy result for these products.

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Process development and supply

Share your feedstock, batch size, solids loading, temperature and pH profile, available treatment time and target specification with Scientific & Technical. These details help match a preparation and starting trial dose to your process. Select the relevant products below to view bottle sizes, current pricing and availability, and buy online.

Use the current technical and safety data sheets for the supplied grade. Avoid enzyme dust and aerosols, and confirm storage and handling requirements before preparing trial solutions.