High-Speed Single-Bevel Top Slitter Knives for Paper Converting & Rewinding

Product Overview

ALAS high-speed top slitter knives are engineered for synchronous shear-cutting operations on industrial slitting-rewinding machinery. Their refined single-bevel circular edges deliver low-vibration performance and stable micro-gap control in continuous, high-volume production. The blades execute clean shearing of cellulose paper fibers without pulling, mitigating edge burrs, web breaks, and airborne paper dust.

Operating Parameters

• Line Speed: Optimized for high-speed slitting lines operating at 300–800 m/min. Maximum safe spindle speed correlates to blade outer diameter (OD) and must be calculated per specific machine configurations.

• Edge Geometry: Standard 45° to 60° single-bevel edge configurations, optimized to shear cellulose paper fibers cleanly without pulling or tearing. Custom multi-bevel profiles are fabricated upon request.

• Cutting Setup: Engineered for synchronous shear cutting. Recommended axial overlap and blade engagement clearance are pre-calibrated according to substrate caliper, basis weight, and specific machine configurations.

Metallurgical Architecture & Physical Advantages

• Materials Selection: Vacuum-degassed AISI M2 High-Speed Steel (DIN 1.3343) or premium AISI D2 Cold-Work Tool Steel (DIN 1.2379).

• Heat Treatment: Precision-controlled multi-stage atmosphere vacuum quenching, liquid nitrogen sub-zero cryogenic stabilization, and controlled tempering to secure a uniform tempered martensitic microstructure. Hardness standard: M2: 61–64 HRC; D2: 59–62 HRC, minimizing microscopic edge rolling and micro-thermal softening under continuous mechanical friction.

• Dimensional Tolerances: CNC dual-axis surface grinding holds thickness tolerance within ±0.002 mm and axial/radial runout to ≤0.003 mm. This supports uniform cutting clearance across the blade stack, minimizing edge burrs and structural paper slitting dust. Inner bore diameter (ID) tolerance is maintained within H7 compliance.

• Surface Finish: Precision mirror lapping and polishing achieves a low-friction face, maintaining a surface roughness profile of Ra ≤ 0.1 μm. This smooth finish prevents loose organic paper fibers from picking up or adhering to the blade sides.

Applications & Machine Integration

• Primary Substrates: High-yield conversion of industrial kraft paper, linerboard, heavy containerboard, fine offset printing paper, and multi-layer packaging laminates.

• Specialty Webs: High-speed, lint-free slitting of delicate tissue paper, cigarette wrapping paper, adhesive-backed label stock, release liners, and spiral-wound paper tube cores.

Equipment Compatibility: Dimensionally compatible with premium international slitting equipment lines, including JAGENBERG, VALMET, GOEBEL IMS, and standard high-speed automated rewinders.

All trademarks are the property of their respective owners; ALAS is not affiliated with these OEMs unless expressly stated.

Customization & Engineering Support

ALAS provides comprehensive manufacturing customization based on client-supplied 2D CAD drawings or OEM replacement part numbers:

• Dimensional Engineering: Custom OD, ID with standardized keyways, overall thicknesses, and custom multi-bevel edge angles. Standard custom manufacturing ranges cover outer diameters from 50 mm to 350 mm.

• Surface Engineering: Optional Nitriding, TiN (Titanium Nitride), or DLC (Diamond-Like Carbon) thin-film vapor depositions to lower friction coefficients and extend preventive regrinding intervals based on specific operating conditions.

• Documentation & Traceability: Material certificates (EN 10204 3.1), Rockwell hardness reports, dimensional inspection reports, dynamic balancing certificates (ISO 1940 G2.5 standard), and certificates of conformance are provided with each production batch.

FAQ | High-Speed Top Slitter Knives

Q1: What is a top slitter knife and how does it differ from a bottom knife?

ALAS top slitter knives are precision circular blades used in shear-cutting configurations, working in pairs with bottom knives. The upper knife rotates via line friction or independent drive, while the lower knife provides the counter-cutting slitting edge. Both must be configured as a matched pair with precise geometric edge angles to maintain consistent cutting clearance.

Q2: What causes burrs during high-speed paper slitting? How do ALAS knives prevent this?

Edge burrs occur when blade clearances are inconsistent or when axial/radial runout exceeds tolerance at high speed. ALAS knives are CNC surface-ground to a ±0.002 mm thickness tolerance and ≤0.003 mm runout, maintaining uniform cutting clearance across the entire blade stack to eliminate edge burrs and airborne paper dust during continuous operation.

Q3: What steel grades are available and which should I choose for paper converting?

ALAS provides two premium tool steels: vacuum-degassed AISI M2 high-speed steel for superior red-hardness and wear resistance at ultra-high line speeds; and AISI D2 cold-work tool steel for structural dimensional stability and heavy-load edge retention. M2 is typically specified for high-speed tissue and cigarette paper lines; D2 for heavy containerboard and multi-layer packaging laminates.

Q4: What is the maximum line speed these knives can handle?

ALAS high-speed top slitter knives are engineered for slitting lines operating at 300–800 m/min. Maximum safe spindle speed depends on blade OD and must be calculated per blade size and machine configuration. Dynamic balancing to ISO 1940 G2.5 or better is executed on request for high-speed operations.

Q5: How does vacuum heat treatment affect blade performance?

ALAS blades undergo multi-stage vacuum quenching, liquid nitrogen cryogenic treatment, and controlled tempering. This produces a uniform tempered martensitic structure rated up to 64 HRC for M2, preventing microscopic edge rolling and micro-thermal softening caused by continuous mechanical friction at high line speeds.

Q6: What edge angle options are available for paper slitting?

Standard configurations utilize 45°–60° single-bevel edges optimized to shear cellulose paper fibers cleanly without pulling. Custom multi-bevel angles are fabricated to match specific substrate thicknesses, coating types, and machine setups.

Q7: Do your blades fit JAGENBERG, VALMET, or GOEBEL IMS machines?

ALAS knives are dimensionally compatible with premium international slitting equipment lines including JAGENBERG, VALMET, GOEBEL IMS, and standard high-speed automated rewinders. We manufacture directly to your 2D CAD drawings or OEM replacement part numbers. All trademarks are the property of their respective owners.

Q8: What coatings can extend blade life between regrinding?

Optional surface engineering includes Nitriding, TiN (Titanium Nitride), and DLC (Diamond-Like Carbon) treatments. These thin-film depositions lower the friction coefficient and extend the interval between preventive regrinding cycles based on individual operating substrates and line speeds.

Q9: Can you manufacture custom diameters, bores, and keyways?

Yes. ALAS provides full custom fabrication based on client-supplied 2D CAD blueprints or OEM replacement part numbers, including custom outer diameters, inner bore diameters with standardized keyways, overall thicknesses, and multi-bevel edge angles.

Q10: What quality documentation is provided with each order?

Available documentation includes EN 10204 3.1 material certificates, Rockwell hardness test reports, dimensional inspection records, dynamic balancing reports, and certificates of conformance. Each blade is traceable by batch number.