Refiner plates are the principal wear components inside a disc, conical, or cylinder refiner. Their bar geometry governs how fibre is treated, how much electrical energy the process consumes per tonne of pulp, and how long the machine runs between plate changes.
1. How Refiner Plates Work
Inside a disc refiner, one plate rotates and one stays fixed. Pulp passes between the two faces. Each time a bar on the rotating plate crosses a bar on the stationary face, a brief intense shear event occurs — this bar crossing fibrillates the cellulose fibres, roughening their surfaces, increasing bonding area, and building the strength properties the finished sheet requires. The groove between the bars carries fibres through the refining zone; groove dimensions are as critical to the result as bar dimensions.
Specific Edge Load (SEL) — energy per unit length of bar crossing, in J/m — determines treatment intensity. Low SEL favours fibre development with minimal cutting and suits tissue and fine-paper grades. High SEL drives more aggressive treatment for coarse furnishes or rapid freeness reduction.
Cutting Edge Length (CEL) — total bar-crossing length per rotor revolution, in km/rev — determines how many treatment events occur per unit time. Higher CEL generally gives more uniform fibrillation at the same power input. A plate specification is the combination of bar geometry that places the process at the right SEL and CEL for the furnish and target quality.
2. Plate Types
Eight types of refiner plate are used across pulp and paper, board, and process industries. The distinctions matter: each type is designed for a specific machine configuration, feed material, and process objective — and specifying the wrong type will not give the correct result regardless of other parameters.
2.1 Pulping Disc Refiner Plates
Pulping disc refiner plates operate in high-consistency defibrators at 20 to 40% consistency, processing wood chips into fibre. Plates are typically three-zone: a coarse outer zone for chip defibration, a transition zone, and a finer inner zone for fibre development. Available from 32″ to 82″ diameter. The 82″ plate is the highest-capacity size; operating data show 600 t/day output at 700 kWh/t energy consumption and 5–8 MW start-up power.
Papermaking disc refiner plates operate at low consistency — 3 to 5% — in stock preparation ahead of the paper machine. The bar pattern is finer than a pulping refiner plate (narrower bars, shallower grooves) to maximise bar crossings per revolution and develop fibre bonding without shortening fibres. Available from 14″ to 58″ and in the CC450 configuration.
2.2 Papermaking Disc Refiner Plates
2.3 Conical Refiner Plates
In a conical refiner the rotor is a tapered plug rotating inside a conical housing. The conical geometry tends to produce lower SEL at equivalent power compared to a disc refiner of similar size, making it well suited to long-fibre furnishes and grades where fibre length must be preserved. Plates are available in integral one-piece castings or in split format — sets of 10 or 14 individual plates per stator or rotor assembly — allowing individual worn plates to be replaced without dismounting the full cone. Four standard integral sizes cover Ø460 to Ø1000 mm; a continuous custom range extends from Ø230 to Ø1350 mm.
Cylinder refiners use a rotating inner drum and a fixed outer shell, with refining on the curved faces between them. The rotor and stator carry opposing bar patterns that follow the cylinder radius. Available in Ø380 mm, Ø450 mm, and Ø650 mm rotor diameters. Used in speciality pulping and certain stock preparation systems.
2.4 Cylinder Refiner Plates
2.5 Heat Dispersion Refiner Plates
Heat dispersion refiner plates are used in hot dispersers on OCC and recycled-fibre lines to reduce ink particles and contaminants to a size that can be removed in downstream flotation or washing. This is not a refining process — the objective is ink particle reduction, not fibre development. The plate surface carries pins or studs rather than bars, generating turbulent blending at 80–95°C. Available from 20″ to 54″, in flat-disc and conical configurations.
MDF refiner plates are designed for thermomechanical fibreboard refining at steam pressure ≥ 8 bar and temperature > 160°C — conditions that exceed what standard paper-mill refiner plates can withstand. The bar geometry is coarser (wider bars, deeper grooves) to handle high-bulk wood chip feed. High-chrome alloy cast iron is mandatory for this application. Available from 24″ to 62″.
2.6 MDF Refiner Plates
2.7 Starch and Pharmaceutical Refiner Plates
Starch and pharma refiner plates apply the disc-refiner principle to particle-size reduction, not fibre development. The plate surface carries pins, not bars. Food-contact applications require 316L stainless steel with food-contact certification. Pharmaceutical applications additionally require a polished surface finish and full batch-level material traceability. Available from 24″ to 48″.
3. Specification and Selection Reference
The three tables below cover plate sizes and specifications, bar geometry parameters, and material grade selection. All dimensional data is sourced from manufacturer catalogues.
TABLE 1 — REFINER PLATE TYPES: AVAILABLE SIZES AND KEY SPECIFICATIONS
| Plate Type | Available Sizes | Refiner Type | Consistency (%) | Bar / Tooth Pattern | Standard Material |
| Pulping Disc Refiner Plates | 32″ · 34″ · 36″ · 38″ · 40″ 42″ · 44″ · 45″ · 48″ · 50″ 52″ · 54″ · 56″ · 58″ · 60″ 62″ · 64″ · 70″ · 82″ | High-consistency disc refiner | 20 – 40 | Multi-zone bar pattern Coarse outer zone → finer inner zone Pattern to furnish specification | High-chrome alloy cast iron |
| Papermaking Disc Refiner Plates | 14″ · 16″ · 17″ · 18″ 20″ · 22″ · 24″ · 26″ · 28″ · 30″ 42″ · 44″ · 46″ · 48″ 52″ · 54″ · 56″ · 58″ · CC450 | Low-consistency disc refiner | 3 – 5 | Fine bar pattern High bar-crossing frequency Pattern to target quality | Martensitic stainless steel High-chrome alloy cast iron |
| Conical Refiner Plates (Integral) | Ø460×360×Ø120 mm Ø600×425×Ø130 mm Ø750×515×Ø220 mm Ø1000×590×Ø440 mm Extended range: Ø230 – Ø1350 mm (custom) | Conical refiner | 3 – 6 | See Table 2 for full bar geometry | High-chrome alloy cast iron Martensitic stainless steel |
| Conical Refiner Plates (Split) | Ø750×515 mm — 10 pcs / set Ø1002×590 mm — 14 pcs / set (rotor large-end dia. × length × pieces per assembly) | Conical refiner | 3 – 6 | See Table 2 for full bar geometry | High-chrome alloy cast iron |
| Cylinder Refiner Plates | Ø380 mm Ø450 mm Ø650 mm (rotor diameter) | Cylinder refiner | 3 – 10 | Curved bar following cylinder radius Rotor and stator in opposing pattern Pattern to application | High-chrome alloy cast iron |
| Heat Dispersion Refiner Plates | 20″ · 28″ · 32″ · 36″ 42″ · 45″ · 47″ · 54″ | Hot disperser (flat-disc or conical) | 20 – 30 | Pin / stud tooth (no continuous bar) See Table 2 for full geometry | High-chrome alloy cast iron |
| MDF Refiner Plates | 24″–36″ · 38″ · 42″ · 44″ 48″ · 50″ · 54″ · 58″ · 60″ · 62″ | Thermomechanical disc refiner (steam-pressure environment) | ≥ 25 | Coarse bar pattern See Table 2 for full bar geometry | High-chrome alloy cast iron (mandatory for ≥ 8 bar steam, > 160°C operating temp.) |
Table 1. Disc plate sizes in inches (″). Conical plate sizes as: Ø rotor large-end dia. × length × Ø shaft-bore (mm). Split format as: Ø rotor large-end dia. × length (mm) — pieces per assembly. Cylinder plate sizes as Ø rotor dia. (mm). Bar and pin dimensions in mm. Consistency in % by weight.
TABLE 2 — BAR AND TOOTH GEOMETRY BY PLATE TYPE
| Plate Type | Bar Angle (°) | Bar Width (mm) | Groove Width (mm) | Groove Depth (mm) | Notes |
| Conical Refiner Plates (all sizes) | 12.5 – 24 | 1.8 – 6.5 | 2 – 8 | 7 – 12 | Applies to all four integral sizes and both split sizes. Specific values within this range are confirmed per machine drawing and process target. |
| Pulping Disc Refiner Plates 32″ – 82″ | 15 – 24 (outer zone typical) | 2.5 – 6.5 | 3 – 8 | 9 – 12 | Three-zone pattern standard on plates 48″ and larger. Outer zone: coarser bar for chip defibration. Inner zone: finer bar for fibre development. 82″ plates use the coarser end of the range to handle feed bulk at high power. |
| Papermaking Disc Refiner Plates 14″ – 58″ | 12.5 – 24 | 1.8 – 6.5 | 2 – 8 | 7 – 12 | Fine end of the range (narrow bar, shallow groove) for low-consistency stock preparation. Coarser end for higher-intensity applications. Tooth pattern specified per customer furnish and quality target. |
| MDF Refiner Plates 24″ – 62″ | 15 – 24 | 3.0 – 7.0 | 4.0 – 9.0 | 10 – 16 | Coarser geometry than any paper-grade plate. Wider bars and deeper grooves to handle high-bulk wood chip feed. Operating conditions: steam pressure ≥ 8 bar, temperature > 160°C. |
| Heat Dispersion Refiner Plates 20″ – 54″ (Pin / stud tooth) | N/A | 3 – 8 (pin dia.) | 4 – 10 (pin gap) | 8 – 14 (pin ht.) | No continuous bar. Pin or stud projections generate turbulent blending, not directed fibre shear. Pin density (pins/cm²) specified per application. Flat-disc and conical configurations both available. |
| Starch / Pharma Refiner Plates 24″ – 48″ (Pin tooth) | N/A | 4 – 10 (pin dia.) | 5 – 12 (pin gap) | 8 – 14 (pin ht.) | Pin-type arc plate. All dimensions in mm. Food-grade or pharma-grade stainless steel 316L. Particle-size reduction, not fibre development. Full material certification with every batch. |
Table 2. All bar dimensions in mm; bar angle in degrees (°). Conical plate parameters are verbatim manufacturer catalogue values. Pin-tooth types (heat dispersion and starch/pharma) use pin diameter, gap, and height in place of bar width, groove width, and groove depth — all in mm.
TABLE 3 — MATERIAL GRADE SELECTION
| Material Grade | Hardness | Abrasion Resistance | Corrosion Resistance | Impact Toughness | Recommended Applications |
| ALLOY GRADES — Pulp, Paper and Board |
| High-Chrome Alloy Cast Iron (HCCI) | HRC 58 – 65 | Very high | Moderate | Low | Pulping disc plates (32″–82″). MDF plates (all sizes — mandatory). Conical and cylinder plates (standard grade). Applications where abrasion is the primary wear mode and tramp-metal risk is managed. |
| Martensitic Stainless Steel | HRC 44 – 56 | High | Good | Good | Papermaking disc plates (standard grade). OCC and recycled-fibre applications. Mildly corrosive process water conditions. Where wear-debris contamination of the pulp is a concern. |
| Austenitic Stainless Steel (18/8) | HB 180 – 240 | Moderate | Very high | Very high | Tissue and fine-paper stock preparation. Low-abrasion, low-intensity refining. Corrosive process environments where maximum corrosion resistance takes priority over hardness. |
| FOOD-CONTACT AND PHARMACEUTICAL GRADES — Starch and Regulated Applications |
| SS 316L (Food-grade) | HB 160 – 210 | Moderate | Excellent | Excellent | Starch processing (corn, wheat, potato). Food ingredient milling. Compliant with food-contact material standards. Material certification and batch traceability supplied with every order. |
| SS 316L (Pharma-grade, polished finish) | HB 160 – 200 | Moderate | Excellent | Excellent | Pharmaceutical milling. Controlled particle-size reduction to GMP standard. Enhanced surface finish (Ra specified per application). Full batch documentation and material traceability to pharma quality standards. |
Table 3. All plates supplied to ISO 9001 quality standards. Hardness values: HRC (Rockwell C scale) for cast iron grades; HB (Brinell) for stainless steel grades. Material certification and dimensional inspection reports supplied with each order.
4. How Specifications Are Determined
Four inputs define the correct plate specification for a given application:
- Furnish: fibre species, virgin or recovered origin, degree of hornification in recycled fibres, and contaminant levels determine the required treatment intensity and alloy grade.
- Target quality: target freeness (CSF or °SR), tensile index, or fibre length distribution sets the operating point on the SEL–CEL map.
- Machine: installed motor power, rotor diameter, rotational speed, and gap adjustment range define the achievable operating envelope for a given plate geometry.
- Operating constraints: plate-change interval, energy cost per tonne, and maintenance schedule determine which specification is economically optimal, not only technically correct.
PMTECS REFINER PLATE SUPPLY
PMTECS supplies the full range of refiner plate types described in this guide — pulping disc, papermaking disc, conical (integral and split), cylinder, heat dispersion, MDF, and starch/pharmaceutical — across the size ranges listed in Table 1. All plates are manufactured to ISO 9001 standards. Each order is accompanied by dimensional inspection reports, hardness test certificates, and full material traceability documentation. Technical enquiries are assessed against machine configuration, current plate specification, furnish type, and process targets before supply is confirmed.
Custom sizes, alloy grades, and bar geometries are available on application for all plate types.
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