Impact of Refiner Plate Types on Pulping Index And Paper Quality

The refiner plate is a critical component of the double disc refiner. In the pulp and papermaking process, the refiner plate's tooth shape and specifications are crucial factors affecting refining performance and resulting paper quality. Its tooth shape not only affects fiber shear strength but also determines pulp fineness distribution and fiber splitting uniformity. A well-designed refiner plate tooth structure can enhance inter-fiber bonding without disrupting fiber length, improving paper flow properties.

The Refiner Plate Tooth Shape Determines The Beating Mechanism

• Cutting fins (sharp teeth): This type of refiner plate is suitable for free-flowing beating, rapidly severing long fibers through high shear, reducing wet weight. However, it has a weak brooming effect, resulting in uniform paper but slightly lower strength.

• Broom fins (blunt teeth with wide, blunt edges): This type of refiner enhances viscous beating, promoting fiber splitting and brooming, significantly increasing beating efficiency, strengthening fiber bonding, and improving the tensile strength and folding resistance of the resulting paper.

• Soft fin (short flat tooth type): This type of refiner plate is targeted at short fibers (straw pulp, chemical pulp), reducing the length of the fibers that are cut and retaining the fibers, resulting in less wet weight loss and significantly improving the paper bulk and tear index.

• relieve fin (Wide Grooves): This type of refiner plate enhances pulp pumping capacity and reduces power consumption, making it suitable for mixing and beating a variety of pulps, reducing fiber clumping, and improving paper uniformity.

The refiner plate has narrow teeth and wide grooves, which increase the specific pressure per unit tooth edge and enhance the cutting performance. The narrow tooth width and grooves increase the friction on the tooth surface and effectively promote the grinding process.

The Impact of Refiner Plate Specifications on The Pulping Process

• Tooth height and groove depth: For example, if the tooth height of a fluting fin is too deep, pumping is fast but fiber exchange is insufficient, which can easily lead to "slurry production". If the tooth height of a broom fin is too shallow, it can increase tooth surface contact and strengthen brooming, but it also increases energy consumption. (The groove depth must match the length of the fiber: the groove width must be greater than or equal to the average fiber length to avoid blockage and ensure the smooth flow of slurry.)

• Sector and Ring Arrangement: Sector-shaped: Wider channels are provided between the sections to alleviate pulp shortages at the outlet of large-diameter refining plates. This is suitable for high-concentration refining and reduces fiber shearing. Ring-shaped: The grinding disc has a high tooth density, which increases the cutting length and is suitable for fine grinding to improve the uniformity of fiber brooming.

Abrasive refiner plate Material and Wear Resistance

High-nickel-chromium alloy abrasive refiner plate offer high wear resistance but low toughness, making them suitable for clean pulps, such as bleached coniferous pulp.

Stainless steel abrasive refiner plate offer excellent impact resistance and are suitable for pulps containing impurities to avoid tooth chipping, such as chemical-mechanical pulp.

How to Choose a Refiner

The tooth shape and specifications of the refiner should be based on the pulp fiber characteristics (long, short, mixed) and the functional requirements of the paper (uniformity, strength, and bulk). The tooth shape is determined by the pulp type, and the specifications are adjusted according to the paper type.

1. Select the refiner plate tooth profile based on the pulp type. For long-fiber pulp (softwood pulp, cotton pulp), the fibers are long and tend to flocculate, so it is important to maintain a balance between cutting and flocculent pulp. For free-fiber beating, a cutting fin refiner plate can be used. This quickly cuts the fibers, reduces wet weight, and improves uniformity. For sticky beating, a broom fin refiner plate can be used to enhance fiber separation and brooming, increasing fiber bonding.

Short fiber pulp (straw pulp, chemical pulp, waste paper pulp) has short fibers that are easy to lose, so it is necessary to reduce cutting and retain the length. Low-cut pulps require soft-fin refiner plate, which reduce wet weight loss and increase bulk. For mixed pulps, a relieve fin refiner plate can be used to reduce power consumption and prevent flocculation.

For mixed pulp (coniferous, broadleaf, chemical-mechanical pulp), it is necessary to balance the cutting and brooming of different fibers. A composite tooth shape can be selected, such as sector partition. The inner ring cutting fins refiner plate cut the long fibers, and the outer ring broom fins refiner plate are used to broom the short fibers to stabilize the beating concentration and improve the uniformity.