SUNRUI Automatic Circle Blanking Line – Maximize Material Utilization with Zigzag Feeding

Keep reading for the full technical breakdown – or skip to the “Why SUNRUI” section for the bottom line.

Whether you produce circles for kitchenware, oil filters, motor laminations, or automotive parts, the way you blank your discs directly impacts your material costs, production speed, and bottom line.

SUNRUI automatic circle blanking lines – also known as zigzag blanking lines, disc blanking lines, zigzag coil feeding lines, or circular blank cutting lines – are engineered for maximum material utilization, fullyautomated operation, and uncompromised blank quality.

Complete System Overview---Step By Step

A SUNRUI automatic circle blanking line is a fully synchronized system that transforms coil stock into finished, stacked circular blanks with minimal scrap and high efficiency. 

Below is a step‑by‑step technical description of each major component, from coil entry to disc stacking.

1. Coil Car

The coil car is a motorized, rail‑mounted carriage designed to safely transfer metal coils from storage to the uncoiler mandrel.

Technical features:

• Expanding mandrel (hydraulic or mechanical) to grip the coil inner diameter

• Motorized drive with speed regulation for loop control

• Drag brake or back‑tension device to prevent over‑run

• Optional heavy‑duty coil reel for thicker or wider coils

Function: Supplies a steady, jerk‑free strip to the leveler using photoelectric loop control, preventing kinks and reducing wear on downstream components.

2. Uncoiler / Decoiler

The uncoiler holds the coil and unwinds the strip at a controlled speed. 

Key features:

• Mandrel with expanding segments (hydraulic or mechanical) to grip the coil inner diameter

• Motorized drive with speed regulation to maintain loop control

• Drag brake or back tension device to prevent over‑run

• Optional coil reel for heavy‑duty applications

The uncoiler supplies a steady strip to the leveler, with photoelectric loop control ensuring smooth, jerk‑free feeding.

3. Straightener / Leveler – 6‑High Roller Leveler

The 6‑high leveler removes coil curvature, crossbow, and edge wave. Unlike conventional 3‑ or 4‑high levelers, 

the 6‑high configuration uses three tiers of rolls:

• Achieves flatness better than 0.5 mm/m²

• Suitable for high‑strength steel and stainless steel

• Driven rolls reduce friction and prevent scratching

Function: The leveler is calibrated for each material thickness and width, producing a perfectly flat strip before it enters the zigzag feeder – essential for high‑quality stamping and subsequent forming.

4. Swing Bridge (Oscillating Bridge) – Buffer & Loop Synchronization

Positioned between the 6‑high leveler and the zigzag feeder, the swing bridge absorbs speed differences between continuous leveling and intermittent (start‑stop) zigzag feeding.

A pivoting arm with position sensors maintains a constant, tension‑free material loop: when the loop drops, the leveler speeds up; when the loop rises too high, the leveler slows down.

Result: No strip buckling or stretching. Continuous leveler operation without frequent starts/stops – prolongs bearing and roll life.

Specifications: Loop control accuracy ±5 mm, compatible with line speeds up to 30 m/min, heavy‑duty pivoting arm with wear‑resistant rollers.

Smooth loop. Steady feed. Zero tension variation.

5. NC Servo Feeder / Zigzag Feeder– The Core of Material Savings

Performs two functions: straight feeding (programmable length/speed) and zigzag (yaw) feeding (lateral movement).

The zigzag pattern nests each circle into the gaps of the previous row.Result: Material utilization increases by 7-25% compared to one‑row blanking.

Specifications: ±0.1 mm accuracy, programmable offset/pitch/sequence, HMI recipe storageOne line. 

One feeder. Hundreds of circle diameters.

6. Punching Press / Stamping Press

The press provides the force required to punch circles from the strip. SUNRUI lines typically use:

• Press force (tonnage) matched to material thickness and circle diameter

• Rigid frame construction to minimize deflection under load

• Programmable slide position and speed

Function: Fully integrated with the feeder and stacker for automatic cycling, ensuring consistent blanking quality over millions of strokes.

7. Circle Stamping Mold / Progressive Die

The mold is custom‑engineered for each circle diameter and material. Options include:

• High‑grade tool steel for long life between regrinds

• Precision ground cutting edges – typical burr ≤0.05 mm

• Quick‑mount clamp system for fast installation

Optional: Slug ejection system to avoid double blanking in high‑precision applications.

8. Conveyor Belt / Circle Feeding Belt

After blanking, the disc separates from the scrap skeleton. A conveyor belt transfers discs from the press exit to the stacking station.Features:

• Four stacking positions: one active, three standby or full

• Pneumatic or servo‑driven lifting table that lowers as stack height increases

• Adjustable side stops to align discs of different diameters

• Count sensor to signal when a stack reaches target height

Operation: Once a stack is full, the system rotates to the next station – uninterrupted production.

9. 4‑Station Stacker / Stacking System

The stacker automatically collects and organizes finished discs into neat piles. The 4‑station design allows continuous operation without stopping the press.

Features:

• Four stacking positions: one active, three standby or full

• Pneumatic or servo‑driven lifting table that lowers as stack height increases

• Adjustable side stops to align discs of different diameters

• Count sensor to signal when a stack reaches target height

Operation: Once a stack is full, the system rotates to the next station – uninterrupted production.

10. Scrap Servo Shear Machine

The scrap skeleton (remaining strip after blanking) is guided into a servo shear, which cuts it into short, manageable pieces – typically 300–500 mm long.Features:

• Clamping elements – hydraulic or pneumatic clamps that secure the die in seconds

• Die cart / roller table – for rolling dies in and out of the press

• Automatic connection – electrical and hydraulic couplers that engage without tools

Performance: Typical changeover time under 10 minutes (compared to 1–2 hours with manual bolting). This makes short production runs and just‑in‑time manufacturing economically viable.

11. Die Quick Change System

To minimize downtime when switching between different circle diameters or part types, SUNRUI offers a die quick change system.

Components:

• Clamping elements – hydraulic or pneumatic clamps that secure the die in seconds

• Die cart / roller table – for rolling dies in and out of the press

• Automatic connection – electrical and hydraulic couplers that engage without tools

Performance: Typical changeover time under 10 minutes (compared to 1–2 hours with manual bolting). This makes short production runs and just‑in‑time manufacturing economically viable.

12. System Integration and Control

All components are coordinated by a central PLC with a large HMI touchscreen. 

The control system manages:<ul list-paddingleft-2">

• Coil loading and tail‑end detection

• Straightener and feeder parameters

• Press stroke and speed

• Stacker indexing and scrap shear timing

• Recipe storage for hundreds of circle sizes

Optional: Remote diagnostics and production data logging for smart factory integration.

1. Unmatched Material Savings

Conventional blanking wastes steel. SUNRUI’s zigzag feeder nests circles into gaps, boosting utilization by 7–25%.

“Less scrap. Less labor. Less downtime.”

2. Fully Automated – One Operator

From coil car to stacker, the line runs itself. One operator manages via HMI. Die change in <10 minutes.

“One operator. One HMI. Hundreds of recipes.”

3. Superior Flatness & Quality

6‑high leveler delivers ultra‑flat strip. Flat circles = better forming, drawing, welding, plus longer die life.

“Flat strip. Flat circles. Flat‑out savings.”

4. Clean, Safe, Reliable, Flexible

Servo shear eliminates scrap tangles. PLC + HMI simplifies complex operations. Integrated design (all components matched by SUNRUI) ensures 24/7 reliability across multiple diameters and materials.

*“Built for 24/7. Backed by 20+ installations.”*

“Before SUNRUI, our material utilization was 78%. With the zigzag blanking line, we now achieve 89%. That’s over 1,000 tons of steel saved per year.”
— Production Manager, major kitchenware manufacturer, China

“The speed is  10-25 pieces per minutes. Now it's 27-40 pieces per minutes due to different diameter circle. We can run small batches economically.”
— Plant Engineer, steel supplier, South Africa.

A SUNRUI automatic disc blanking line is a complete solution – from coil car to stacker – built for precision, speed, and long‑term profitability.

Contact SUNRUI today for a customized quotation or a virtual demo.

Let us show you exactly how much you can save – with numbers from your own coil width and circle diameter.

SUNRUI – Intelligent blanking lines for a smarter workshop.