company news about Tungsten Carbide Circular Knives for Tobacco Industry: Common Sizes & Complete Selection Guide

In the high-speed automated production lines of the tobacco industry, tungsten carbide circular knives are hailed as the "guardian of precision" — whether it's cutting filter rods, slitting cigarette paper, or processing tobacco sheets, the dimensional accuracy and material performance of the knives directly determine the smoothness of the cut and the stability of cigarette quality. Moreover, the tobacco production equipment comes in a variety of models (such as mainstream brands like Hauni, G.D, and Molins), and the corresponding circular knife specifications must be accurately matched. This guide thoroughly explains the common sizes of tungsten carbide circular knives used in the tobacco industry and provides a set of practical selection methods to help you quickly choose the right knife for your equipment, avoiding detours.

Circular knives in tobacco machinery operate at speeds of thousands of revolutions per minute, making them "high-speed rotating precision instruments." Even the slightest deviation in the inner diameter or thickness of the knife can cause a series of problems:

• Equipment Malfunctions: If the inner diameter does not fit tightly with the main shaft, the knife will jump and vibrate, resulting in loud noise, accelerated main shaft wear, and shortened equipment lifespan;
• Product Defects: Inconsistent knife thickness disrupts the spacing of multi-knife sets, leading to uneven slitting widths of cigarette paper and directly affecting subsequent rolling processes;
• Material Damage: Irregular dimensions increase cutting friction, causing the knife to overheat. This can scorch cigarette paper and filter rods at best, and affect tobacco taste and product qualification rates at worst.

There are three core dimensions of tobacco circular knives: Outer Diameter (OD), Inner Diameter (ID), and Thickness (T). Below is a summary of common specifications corresponding to mainstream equipment on the market, which can be directly referenced:

Filter rod cutting has the highest requirements for sharpness and wear resistance, and ultrafine-grained tungsten carbide ensures no edge chipping and neat cuts during long-term cutting.

Mainly used to slit large rolls of cigarette paper into narrow strips. These knives are generally thin, focusing on precise slitting width.

• Common Outer Diameter: 40mm - 80mm (mainstream: 60mm, 80mm)
• Common Inner Diameter: 10mm - 30mm (compatible with different slitter main shafts)
• Common Thickness: 0.15mm (ultra-thin, for thin cigarette paper), 0.20mm (universal), 0.30mm (for thick paper)
• Application Tip: Choose 0.15-0.20mm for thin paper and 0.30mm for thick-coated cigarette paper to avoid knife bending.

Tipping paper has printing and coatings, so cutting must avoid scratching patterns. Specifications are relatively fixed:

• Mainstream Outer Diameter: 60mm or 80mm
• Common Thickness: 0.25mm (universal), 0.30mm (for high-speed production lines)
• Key Requirement: The cutting edge must be sharp and smooth to prevent ink smearing.

Outer diameter, inner diameter, and thickness are the basics, but to ensure long knife life and stable cutting, these 4 "hidden parameters" must be closely monitored:

1. Flatness: The "lifeline" of thin knives! For example, a 0.2mm thick knife requires flatness within 0.005mm (equivalent to 5 microns); otherwise, it will swing left and right during high-speed rotation, resulting in crooked paper edges;
2. Concentricity: Simply put, "the inner and outer circles must be concentric." Poor concentricity causes periodic "deep and shallow cuts" during slitting, leading to burrs on filter rod edges;
3. Cutting Edge Angle: Choosing the right angle greatly improves cutting performance:
   • Single-Sided Edge: Produces straighter, smoother cuts, suitable for precision slitting of cigarette paper and thin filter rods;
   • Double-Sided Edge: More uniform force distribution, 30% more durable than single-sided edges, suitable for thick filter rods and fibrous tobacco sheets;
4. Surface Finish: It is recommended to choose mirror-polished knives (Ra < 0.1μm) — tobacco dust and glue are less likely to adhere to the smooth surface, reducing downtime for cleaning and improving production efficiency.

In the past, many production lines used High-Speed Steel (HSS) knives, but now high-end lines have basically switched to tungsten carbide (cemented carbide). The core advantages are threefold:

• Extended Lifespan: Tungsten carbide circular knives have a 10-20 times longer service life than HSS knives. Previously, HSS knives needed replacement every week, while tungsten carbide can last 1-2 months, significantly reducing downtime for knife changes;
• Long-Lasting Sharpness: Ultrafine-grained tungsten carbide maintains a micron-level cutting edge for a long time, ensuring consistent smooth cuts without worsening burrs;
• Heat Resistance Without Softening: Continuous high-speed cutting increases knife temperature, but tungsten carbide does not anneal and soften like HSS, avoiding edge deformation that affects cutting accuracy.

Not sure which specification to choose? Follow these 3 steps for accurate matching without mistakes:

1. Check Equipment Manuals: Prioritize consulting the original manuals of Hauni, G.D, and other equipment, which list the OEM part numbers and corresponding outer diameter, inner diameter, and thickness. Buying directly according to these specifications is the safest;
2. Precise Physical Measurement: Use a micrometer with 0.001mm precision to measure the inner diameter and thickness of old knives (do not reference the outer diameter if it is severely worn; follow the manual standard). Measure multiple points to avoid errors caused by old knife deformation;
3. Fine-Tune Based on Working Conditions: If the production line speed is extremely high (e.g., over 10,000 cigarettes per minute), slightly increase the thickness (e.g., from 0.25mm to 0.28mm) to enhance knife rigidity and reduce vibration. For slitting thin paper or thin filter rods, choose thinner knives to ensure smooth cuts.

Selecting tungsten carbide circular knives for the tobacco industry relies on two core principles: precise matching to equipment models (check outer and inner diameters) and adaptation to cutting conditions (check thickness and cutting edge angle). The three outer diameters of 60mm, 63mm, and 100mm can cover 80% of production needs. However, it should be noted that compared to dimensions, "invisible" indicators such as tungsten carbide grade (e.g., ultrafine-grained) and processing accuracy (flatness, concentricity) are the keys to reducing long-term operating costs. Choosing the right knife not only extends service life but also reduces product defects and improves production line efficiency.