Slitting Process — Setup, Parameters & Quality Control

A practical engineering reference for slitting process setup, parameter selection, and quality control in metal, film, and foil operations.

Process Overview

The slitting process converts a wide master roll into multiple narrower slit strips through a sequence of: unwind → tension control → knife cutting → rewind. Each stage has parameters that affect output quality.

Setup Sequence

  1. Mount and align knife pairs to specification width
  2. Set knife clearance based on material and thickness
  3. Set knife overlap (penetration depth)
  4. Set unwind and rewind tensions
  5. Run test strip at 20% of target speed
  6. Inspect edge quality — adjust clearance if needed
  7. Ramp to production speed

Common Defects & Causes

DefectPrimary CauseCorrective Action
Burrs on edgeClearance too large or dull knivesReduce clearance, regrind knives
Edge curlClearance too small or excessive overlapIncrease clearance slightly
Material tearingSpeed too high, tension too lowReduce speed, increase tension
Width variationKnife migration or loose spacersCheck spacer fit, tighten arbor

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Frequently Asked Questions

What causes burrs in slitting?

Burrs are caused by incorrect knife clearance (usually too large), dull knives, misaligned knife pairs, or excessive cutting speed for the material. Carbide knives with ±0.002mm tolerance significantly reduce burr formation.

How do I set up knife clearance for a new material?

Start at 5% of material thickness for steel, 3% for aluminum, and 0–1% for precision films. Run a short test strip, inspect the edge under magnification, and adjust ±1% until edge quality is acceptable. Record the final setting in your process sheet.

What is the correct knife overlap for metal slitting?

For metal slitting, knife overlap (vertical engagement) is typically 0.5–1.5mm. Insufficient overlap causes incomplete cuts; excessive overlap accelerates wear. For stainless steel above 2mm thickness, increase overlap to 2mm.

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TOA DR Engineering Team

Precision Slitting Specialists

TOA DR Enterprise Co., Ltd. has manufactured precision slitting knives and spacer rings since 1972. Our engineering team brings decades of hands-on experience in metal slitting, film slitting, and high-precision applications.