How Creping Blade Makes High Quality Tissue Paper

Why The Creping Blade Is Needed

In the papermaking industry, especially in tissue manufacturing, the creping blade plays an important role.

The semi dry paper web is scraped off the surface of a high speed rotating Yankee dryer, instantly forming fine, dense creases that shorten the paper’s length, increase its thickness, and impart a soft texture. This process gives tissue paper soft, fluffy, and crinkled texture characteristics.

The creping blade is an indispensable consumable in the manufacturing process of tissue paper. Its primary function is to peel the paper web away from the surface of the drying cylinder and apply precise pressure to the contact area, thereby imparting a distinctive crinkled texture to the paper.

The quality of the creping blade directly impacts product quality and production efficiency. Therefore, the creping doctor must possess exceptional wear resistance, appropriate sharpness, a certaindegree of flexibility, and a cross sectional profile that precisely matches the creasing process technology.

The application of high quality creping blades not only enhances product quality but also assists papermaking enterprises in achieving process stability and product innovation, thereby providing consumers with a softer and more comfortable experience with household paper products.

How Creping Blade Influences Tissue Creping

During the creping process utilizing the creping doctor blade, various factors come into play. These factors influence not only the degree and quality of the paper creping but also the service life of the creping blade itself.

Blade Ripple Pitch

Customization is available to meet specific requirements. The deeper the ripples of the creping blade, the more pronounced the increase in paper thickness, and the more prominent the resulting surface texture.

Doctor Blade Angle

A smaller angle yields finer creping. However, it also results in faster wear of the creping blade. The commonly used angle range is 70–90°.

For high speed tissue machines, an excessively small angle may lead to difficulties in sheet threading. Therefore, maintaining the angle of the creping doctor blade within the range of 75–90° is considered ideal.

Pressure Load

The pressure load on the creping blade not only influences the cracking of the adhesive layer but also affects the service life of the creping doctor blade.

The higher the blade load, the more susceptible the blade tip is to wear. Typically, this load is maintained within the range of 1.8 to 3.5 N/mm.

Creping Blade Material

Selecting the appropriate creping blade material for creping on a Yankee cylinder is crucial. The range of material options extends from steel blades and long-life alloy blades to thermal-sprayed ceramic-coated blades.

Factors to consider when selecting a creping blade material include: target blade performance, the condition of the Yankee cylinder surface (including its chemical spray treatment), and the quality requirements of the paper product.

Carbon steel creping blade: It is one of the most traditional and widely used materials for creping blades. Characterized by their sharp edges, moderate hardness, and low processing costs, they are very common in low and medium speed paper machines and in the production of standard tissue paper.

Ceramic coating creping blade: Extremely high hardness; wear resistance far exceeds that of alloy steel; resistant to high temperatures and chemical corrosion; long service life; effectively reduces knife marks and paper defects. However, ceramic blades are brittle and have poor impact resistance, so care must be taken to ensure stability during installation and use.

Wrinkling Rate

a=(V1➖V2)/V2×100%

V1 is the pre corrugation speed (the drying cylinder speed), and V2 is the post corrugation speed (the reel cylinder speed).

Changes in the creasing rate are typically achieved by adjusting the speed of the winding cylinder. If the creasing rate is high, the web’s dwell time on the creping blade increases, resulting in coarse and deep creases. If the creping rate is reduced, the web’s dwell time on the creping doctor blade decreases, resulting in shallower and finer creases.