Deflaker vs Refiner

What Is a Deflaker?

A deflaker generally refers to a fiber deflaker or a high-frequency deflaker, both of which are key pieces of equipment in the stock preparation system of the pulp and paper industry.

A deflaker is mainly used to loosen and homogenize pulp after cleaning and purification. It breaks up fiber flocs and agglomerates, allowing the fibers to change from a bundled state into uniformly dispersed individual fibers, without cutting the fibers or significantly reducing their strength. As a result, the paper produced on the paper machine becomes more uniform, with fewer coarse spots and surface defects.

What Is a Refiner?

A refiner usually refers to a double-disc refiner, high-consistency refiner, or conical refiner, all of which are core equipment in the stock preparation system of the pulp and paper industry.

The main function of a refiner is to mechanically treat fibers, altering their morphology in order to improve the physical properties of paper. Through mechanical actions such as shearing, compression, and friction, the refiner modifies the fiber structure, enhances fiber bonding ability, and increases paper strength.

Deflaker vs Refiner – What Problems Do They Mainly Solve?

Deflaker:
During pulping or wastepaper recycling, common problems include fiber bundles and flocs. The pulp is poorly dispersed, with undisintegrated coarse particles, and the stock is unstable before refining.
The function of a deflaker is to break up flocculated fiber bundles, improve pulp dispersion, and disintegrate or reduce coarse particles without cutting the fibers, thereby avoiding the risk of reduced paper strength.

Refiner:
Pulp that has not been refined or is insufficiently refined usually has the following issues: smooth fiber surfaces and weak bonding ability. As a result, the paper shows low strength (tensile and burst strength), a loose sheet structure, and poor formation and retention.
The function of a refiner is to fibrillate and split the outer layers of fibers, enhance fiber bonding, increase tensile and burst strength, strengthen the paper sheet, improve sheet structure, enhance formation, and improve web-forming performance.

Deflaker vs Refiner – Key Differences

The main differences between a deflaker and a refiner are as follows:

I. Different Core Functions

1. Deflaker — “Separating” the fibers
Main function: Dispersion and deflaking of fiber bundles
Purpose: To disintegrate undispersed fiber bundles and reduce shives, improving pulp uniformity
Does not change fiber length or fineness
“Deflaking, not refining”
It ensures uniform fiber dispersion and prepares the pulp for subsequent refining or papermaking.

2. Refiner — “Processing” the fibers
Main function: Fiber plasticization, swelling, cutting, and fibrillation
Purpose: To improve fiber bonding ability and enhance paper strength and performance
Does change fiber shape, fiber length, and surface structure
“Altering fiber structure to enhance bonding”

II. Differences in Working Principles

Deflaker
• Operates at high frequency
• Larger plate gap
• Mainly relies on high-speed shear forces to disintegrate fiber bundles
• Causes minimal damage to fibers

Refiner
• Operates at lower frequency with high torque
• Smaller plate gap
• Relies on friction to modify fiber structure
• Causes fiber fibrillation, cutting, and outer-layer peeling

III. Differences in Impact on Fibers

Item	Deflaker	Refiner
Fiber length	Essentially unchanged	Shortened
Fiber fineness	Unchanged	Increased
Fiber flexibility	No significant improvement	Significantly improved
Fiber bundles (shives)	Effectively dispersed/disintegrated	Partially treated (not primary purpose)
Paper strength	Indirectly improved (via dispersion)	Directly improved

IV. Differences in Installation Position

Deflaker – typically installed:
✔ After pulping
✔ Before screening
✔ Before refining
✔ In the approach flow system

Functions:
• Removing coarse contaminants
• Improving pulp uniformity
• Enhancing system stability

Refiner – typically installed:
✔ In the main refining section
✔ Final refining before the paper machine

Functions:
• Directly determines paper strength, bulk, absorbency, and other properties

V. Differences in Typical Applications

Deflaker is suitable for:
• Recycled pulp (OCC, ONP) with many shives
• Non-wood pulp with abundant fiber bundles
• Paper grades with high dispersion requirements
• Improving screening efficiency
• Improving refining efficiency

Refiner is suitable for:
• Paper grades with high strength requirements
• Cultural paper, coated paper, tissue paper, and specialty paper
• Various pulping processes requiring fiber property adjustment

VI. One-Sentence Summary

Deflaker: Responsible for dispersing fiber bundles
Refiner: Responsible for processing the fibers themselves

A deflaker cannot replace a refiner, and a refiner cannot replace a deflaker.

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