Tungsten Carbide Circular Knives for Paper Straw Cutting

Paper straws are made by feeding food-grade paper reels into a machine, applying a water-based adhesive between several layers, and winding the layers in a spiral around a mandrel to form a continuous tube. A rotary cutting unit then severs the tube into straws of uniform length. One machine maker describes its nine-cutter paper straw machine as handling 60–120 gsm paper and producing straws of roughly 4.2–13 mm outer diameter, with rotary blades responsible for clean, even lengths.
A circular knife of this kind typically works in two places on a straw line:
• Cut-to-length – the tube leaves the winding section continuously and the knife cuts it into finished lengths, often while the tube is still moving.
• Bevel (sharp-end) cutting – a separate sub-machine cuts one or both ends at an angle so the straw can pierce sealed cup lids or juice-carton foil. One commercial bevel-cutting machine is rated at 800 straws per minute for straw inner diameters of 3–15 mm.
Related knife use: paper-slitting sections upstream (cutting wide paper rolls into narrow strips for winding) run on circular blades as well. A straw-machine slitting unit is specified for paper of 20–300 gsm.

The primary application is the online cutting of continuously produced paper tubes into individual paper drinking straws.

Typical cutting operations include:

Continuous Tube Cutting: Cutting continuously wound paper tubes into individual straw sections during production.

Length Control: Producing paper straws with consistent specified lengths, such as 150 mm, 197 mm, 200 mm, or other customized lengths.

Clean Edge Cutting: Achieving smooth and neat cut surfaces while minimizing paper fiber tearing and layer separation.

High-Speed Production: Supporting automatic cutting systems operating at high production speeds.

Multi-Blade Cutting: Working with multi-knife cutting assemblies to improve production capacity.

Paper straw cutting is generally integrated into the production line rather than performed as a separate offline operation.

For example, commercial paper straw machines use servo-controlled multi-knife systems and synchronized cutting mechanisms. Some equipment specifications indicate production speeds of 30–80 m/min or higher, depending on the machine configuration and product dimensions.