Aluminum strip is the common name for aluminum sheet and foil in rolls with a thickness > 0.2mm and a width of 20mm to 100mm. The common name for aluminium strip that is produced in small strip widths is usually split strip. Aluminum sheets are cut into a required by slitting tooling, the raw material of the aluminum strip is pure aluminum or aluminum alloy hot rolled cast-rolling aluminum coil and hot-rolled coil. A cold-rolled machine to form different thicknesses and widths of the rolling sheet and aluminum coil, and then the vertical cutting and slitting machine for different widths of the strip. If the thickness is ＜0.2mm, we call it an aluminum foil strip or aluminum foil coil.

Alloy Grade of Aluminum Strip

1050 Aluminium Strip

1060 Aluminium Strip

1070 Aluminium Strip

1100 Aluminium Strip

3003 Aluminium Strip

3105 Aluminium Strip

5052 Aluminium Strip

5754 Aluminium Strip

6061 Aluminium Strip

Slitting Standard for Aluminum Strip (Thickness above 0.2mm)

1. Thickness Tolerance (t ≥ 0.2mm)

Regular Grade

• 0.2～0.5mm：±0.01mm
• 0.5～2.0mm：±0.02mm
• Over 2.0mm：±1.0% of nominal thickness

High Precision Grade

• 0.2～0.5mm：±0.006mm
• 0.5～2.0mm：±0.012mm
• Over 2.0mm：±0.6% of nominal thickness

2. Width Tolerance after Slitting

Regular Grade

• Width ≤500mm：±0.5mm
• 500～1000mm：±1.0mm
• Width ＞1000mm：±1.5mm

High Precision Grade

• Width ≤500mm：±0.2mm
• 500～1000mm：±0.5mm
• Width ＞1000mm：±0.8mm

3. Edge & Cutting Quality (t ≥ 0.2mm)

• Edge burr: ≤0.1mm, no sharp edge, no black burrs or continuous burrs
• Cutting verticality: ≤ 0.5% of strip thickness
• Edge straightness: ≤1mm/m
• End face: neat cutting, no metal chips adhesion, no edge collapse or burn mark

4. Flatness & Rolling Quality

Camber

• High Precision Grade: ≤1mm/m
• Regular Grade: ≤2mm/m

Roll Misalignment / Tower Shape

• High Precision Grade: ≤3mm
• Regular Grade: ≤5mm
• End face crown: overall tolerance ±1mm
• Wave flatness: ≤1mm/m (High Precision Grade)
   

5. Surface Quality

6. Inner / Outer Diameter

• Inner diameter: as per customer order, tolerance ±0.5mm
• Outer diameter: as per order requirement; even rolling tightness, no loose coil.

Aluminium Strip Manufacturing Process:

1.Material Preparation and Inspection
The slitting process of aluminum strips begins with acquiring large coils or sheets of aluminum from suppliers. Before entering the slitting process, meticulous inspection of the aluminum material is essential to ensure it meets quality standards. This includes checking surface quality, thickness uniformity, and identifying any physical defects to ensure the final slit aluminum strips maintain stable quality and performance.

2.Setting and Adjusting Cutting Parameters
Setting and adjusting parameters on the slitting machine is a critical step. Operators adjust cutting width, length, blade position, and speed based on product specifications and customer requirements. Precision in these settings is crucial to ensure consistency in the dimensions of each slit strip, particularly in high-volume production scenarios where automation control systems enhance production efficiency and accuracy.

3.Cutting Operation and Techniques of Aluminum Strip
Once settings are finalized, aluminum coils or sheets are fed into the slitting machine for cutting. The machine is equipped with specialized cutting blades or wheels capable of swiftly and accurately slicing through the aluminum material. During cutting, attention is paid to blade sharpness and cutting speed to maintain edge quality and surface smoothness. In some cases, specialized cutting techniques such as laser cutting or water jet cutting may be employed to handle specific requirements or complex shapes of aluminum strips.

4.Quality Control and Inspection
After cutting, the slit aluminum strips are collected and either moved to the next processing stage or undergo quality inspection. Quality control involves checking the dimensional accuracy, surface quality, and identifying any physical defects or damage. Precision measurement equipment and visual inspection systems ensure all products meet customer technical specifications and standards.

Common Problems in Aluminum Strip Slitting

Aluminum strip slitting (longitudinal shearing) frequently encounters problems mainly falling into six major categories: cut edge defects, dimensional inaccuracy, flatness & surface flaws, rewinding defects, strip breakage, and equipment malfunctions, which directly affect yield and finished product quality. Below is a systematic summary of frequent issues with phenomena, causes and solutions:
1. Cut Edge Defects (Most Common)
1.1 Edge Burrs
Phenomenon: Sharp metal burrs, zigzag or wire-drawing marks on slit edges.Causes:
Blunt, chipped or notched blades
Improper blade gap/overlap: Excessive gap → tearing burrs; Too small gap → extrusion burrs
Winding shaft runout, poor blade parallelism, worn blade spacers
Unstable tension and strip vibration
Solutions:
Regular blade grinding and replacement (service life: 100–200 working hours)
Gap setting by thickness: 0.1–0.5mm thickness → gap = 5%–8% of thickness; overlap = 10%–30% of thickness
Control winding shaft runout ≤ 0.01mm and calibrate blade parallelism
1.2 Edge Waviness & Tearing
Phenomenon: Wavy edges, uneven edges or local tearing and aluminum debris falling off.Causes:
Excessive/insufficient tension and tension fluctuation
Dull blades, misaligned blades, strip deviation
Poor incoming material flatness (edge wave / center wave)
Solutions:
Maintain constant slitting tension; adopt taper tension for rewinding
Ensure normal EPC edge position control and parallel guide rollers
1.3 Cut Edge Indentation
Phenomenon: Local depressions or bright marks near slit edges.Causes:
Excessive pressure of pinch rollers, aluminum powder adhesion on roller surface
Sharp corners of blade spacers/gaskets, assembly misalignment
Solutions:
Clean blade spacers and polish sharp corners; adjust pinch roller pressure properly
2. Dimensional Accuracy Problems
2.1 Width Out of Tolerance
Phenomenon: Width deviation over ±0.1mm; uneven width in the same coil or blade shaft.Causes:
Inaccurate blade positioning, cumulative error of blade spacers
Strip deviation, failed EPC correction
Strip stretching/shrinking caused by tension fluctuation
Winding shaft axial play, loose blades
Solutions:
Precise blade alignment and calibration with standard gauges
Clean EPC sensors and calibrate edge correction system
Fasten blade base and control tension fluctuation within ±5%
2.2 Longitudinal Camber (S-curve)
Phenomenon: The slit strip bends to one side and runs obliquely.Causes:
Uneven left-right tension, non-vertical blade set, non-parallel guide rollers
Inhomogeneous flatness of incoming material, thickness difference on both sides
Solutions:
Level guide rollers, adjust blade set to vertical state; balance tension on both sides
3. Surface Defects
3.1 Scratches & Bright Marks
Phenomenon: Linear/pitted scratches, indentations or bright bands on the surface.Causes:
Aluminum powder dirt and rough surface on guide rollers/tension rollers
Scratches from sharp corners of blade spacers/gaskets
Lateral pushing by edge correction, friction from strip vibration
Solutions:
Clean guide rollers daily and polish regularly
Optimize blade spacer assembly to eliminate sharp corners
3.2 Oil Stains & Aluminum Powder Adhesion
Phenomenon: Oil marks, blackening and accumulated aluminum powder on the surface.Causes:
Excessive lubricating oil/emulsion, poor cleaning effect
Residual aluminum powder generated during slitting without timely blowing
Solutions:
Control oil dosage, install air knife blowing device and filter circulating oil
4. Rewinding Defects (Affecting Subsequent Processing)
4.1 Layer Dislocation & Tower-shaped Coil
Phenomenon: Layer misalignment, uneven end face, tower-shaped winding.Causes:
Insufficient rewinding tension, loose layers, axial play
Non-uniform sleeve inner diameter, unexpanded air shaft
Non-parallel guide rollers/rewinding shaft
Solutions:
Properly increase rewinding tension and enable taper tension
Use unified specification sleeves, fully inflate air shaft, calibrate roller parallelism
4.2 Inner Layer Wrinkles & Indentations
Phenomenon: Wrinkles and indentations on inner coil, uneven tightness.Causes:
Excessive initial tension → inner layer collapse; Insufficient tension → loose layer wrinkles
Incorrect taper tension setting (no reduction with coil diameter increase)
Solutions:
Low tension for inner winding, gradual tension increase for outer layer (taper ratio: 10%–30%)
Match pressure of slip shaft and air shaft
4.3 Uneven Winding & Tightness Difference
Phenomenon: Concave-convex end face, uneven coil hardness, rebound during unwinding.Causes:
Tension fluctuation, delayed edge correction response
Mismatch between rewinding speed and line speed
Solutions:
Adopt closed-loop tension control and synchronous speed regulation
5. Strip Breakage (Major Cause of Downtime)
Phenomenon: Aluminum strip breaks halfway during slitting or rewinding, frequent shutdowns.Causes:
Tension exceeding yield strength, propagation of micro cracks on cut edges
Tearing from dull blades and stress concentration at burrs
Poor flatness, defective joint connection, foreign object jamming
Stuck guide rollers, unilateral pulling by edge correction
Solutions:
Reduce tension, replace sharp blades timely and optimize blade gap
Pre-adjust material flatness, inspect strip joints and clean material passage
6. Equipment & System Faults
Winding shaft vibration & abnormal noise: Worn bearings, insufficient lubrication, unbalanced blades
EPC failure: Dirty sensors, signal drift, stuck actuator
Unstable tension: Stuck floating roller, faulty cylinder/motor, sensor drift
Rewinding slipping: Air shaft air leakage, failed slip shaft, worn roller surface
7. Special Problems for Ultra-thin & Hard Alloy Strip
Ultra-thin aluminum strip (＜0.1mm): Prone to breakage, wrinkles and deviation; require lower tension, sharper blades and smaller gap
Hard alloy (3003/5052/H18): Severe burrs and edge tearing; require high-hardness blades, precise gap and stable tension
5-step Quick Troubleshooting Checklist
Blade: Sharp enough? Correct gap & overlap? Good parallelism?
Tension: Stable? Reasonable taper setting?
Guide Roller & EPC: Clean, parallel and flexible rotation?
Flatness: Any wave, camber or thickness difference on incoming material?
Speed: Excessively fast speed causing vibration and strip breakage?