Paper Making VFD Solutions

High-Performance Variable Frequency Drives for Paper Machines, Pulpers, Winders, and Converting Lines

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Overview

The paper making industry demands extreme reliability, precise speed control, and load sharing across multiple sections of a paper machine. From pulping and stock preparation to the wet end, press section, dryer cans, calender stack, and reel – every section must run at a precisely coordinated speed to avoid sheet breaks, wrinkles, or uneven basis weight.

At Inomax Technology, we provide dedicated variable frequency drives (VFDs) engineered specifically for paper machine applications. Our ACS series (ACS880 AFE, ACS890 multi-module, ACS580 servo) are the primary choices for paper making, delivering microsecond-level speed synchronization, load sharing between multiple motors on a single section, torque control for winders, and energy savings – all in rugged packages designed for hot, humid, and dusty mill environments.

For other mill auxiliary applications (fans, pumps, conveyors), our MAX500 general purpose drives and MAX600 HVAC drives offer cost-effective solutions.

Whether you are building a new paper machine, upgrading an existing drive system, or optimizing a rewinder or slitter, our engineering team delivers customized VFD solutions that improve machine efficiency, reduce sheet breaks, and increase production.

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Key Applications in Paper Making

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Industry Challenges & Our Solutions

Challenge 1: Speed Chain Synchronization

Paper machines have 20–60 driven sections that must run at precisely coordinated speeds. Even a 0.01% speed difference causes sheet tension changes, wrinkles, or breaks.

Our Solution (ACS880/ACS890)
Electronic speed chain using high-speed communication (Profinet IRT, EtherCAT). One VFD acts as master (usually the reel or a reference section), and all other VFDs follow with programmable draw (speed difference). Draw values are typically 0.1–2.0% between sections. Our drives support draw adjustment on-the-fly via HMI or PLC without stopping the machine.

Challenge 2: Load Sharing (Multiple Motors on One Section)

Paper machine sections like the wire and press often have multiple motors driving the same roll or fabric. Without proper load sharing, one motor can overload.

Our Solution (ACS880/ACS890)
Master-follower load sharing with torque reference broadcast. One VFD operates in speed control (master). All other VFDs on the same section operate in torque control, receiving the master’s torque reference. This ensures each motor contributes equally.

Challenge 3: Tension Control on Winders and Unwinds

Winders and unwinds require precise tension to produce uniform rolls without telescoping or crushing.

Our Solution (ACS880 AFE)
Closed-loop tension control with load cell or dancer feedback. Built-in taper tension algorithm automatically reduces tension as roll diameter increases, using diameter calculated from line speed / roll RPM.

Challenge 4: Regenerative Energy (Unwind Braking)

Unwind stands and downhill conveyors generate regenerative energy.

Our Solution (ACS880 AFE)
Active Front End (AFE) returns >95% of braking energy to the grid, reducing electrical costs. For smaller applications, we offer braking resistor modules.

Challenge 5: Harsh Mill Environment

Paper mills are hot (40–50°C), humid (up to 95% RH), and filled with paper dust and water spray.

Our Solution
IP54 and IP66 enclosures with conformal-coated circuit boards. Stainless steel versions for washdown areas. Extended temperature range rating (-10°C to +55°C).

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Product Series for Paper Making

Note: For all critical paper machine sections (wet end, press, dryer, winder), we recommend ACS880 AFE or ACS890. The MAX series are intended for auxiliary services only.

Application Case Studies

Case Study 1: Kraft Paper Machine Drive Retrofit (ACS880 AFE)

Location: Southeast Asia
Machine: 4.2m wide kraft paper machine, 250 tons/day
Old system: 1980s DC drives (24 drives, total 4.2 MW)
Problems: Frequent drive failures, poor speed regulation (0.5% error), high maintenance costs, energy inefficiency

Solution: Replaced all DC drives with ACS880 AFE VFDs (1.5 kW to 500 kW units). Installed Profinet IRT network for speed chain synchronization. Integrated with existing DCS.

Results:

• Speed regulation improved from ±0.5% to ±0.01%

• Sheet break frequency reduced by 45% (from 12 to 7 breaks per day)

• Energy consumption reduced by 11% (AFE regenerative braking on winder)

• Maintenance cost reduction: $85,000/year (no more DC brush/commutator replacement)

• Payback period: 18 months

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Case Study 2: High-Speed Tissue Winder Upgrade (ACS880 AFE + Taper Tension)

Location: North America
Machine: Twin-drum tissue rewinder, 2,000 m/min operating speed, 2.8m width
Problem: Roll hardness variation (±20%) caused customer complaints; frequent telescoping; rider roll control unstable

Solution: Installed ACS880 AFE drives on unwind and rewind. Implemented closed-loop tension control with load cells, taper tension algorithm (linear from 100% at core to 55% at full diameter), and rider roll load profiling.

Results:

• Roll hardness variation reduced to ±4%

• Telescoping complaints dropped by 90%

• Winder speed increased from 1,800 to 2,000 m/min (10% throughput gain)

• Energy recovery via AFE: 85,000 kWh/year saved

• Payback: 14 months

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Case Study 3: Supercalender Drive Modernization (ACS890 Multi-Module)

Location: Europe
Machine: 6-roll supercalender for coated paper, 5.5m width, 1,200 m/min
Problem: Existing drives could not handle load sharing between top and bottom rolls; nip pressure variations caused uneven gloss; frequent drive overload trips

Solution: Installed ACS890 multi-module drive system (2 × 800 kW modules on common DC bus). Configured master-follower torque control for load sharing. Added temperature compensation for roll expansion.

Results:

• Gloss uniformity improved by 35%

• Drive overload trips eliminated (zero in 18 months)

• Load sharing accuracy: ±3% between motors

• Production increase: 8% due to reduced downtime

• Payback: 22 months

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Case Study 4: Cut-to-Length Sheeter Flying Knife (ACS580 Servo)

Location: China
Machine: Folio sheeter for printing paper, 300 m/min, cut length range 400–1,800 mm
Problem: Old clutch/brake system had cut length accuracy ±3 mm, frequent clutch wear, high noise

Solution: Replaced clutch/brake with ACS580 servo drive + induction motor. Configured electronic cam profile for flying knife. Integrated with main web drive encoder.

Results:

• Cut length accuracy improved to ±0.5 mm

• Production speed increased from 250 to 300 m/min

• Clutch maintenance eliminated (saving $12,000/year)

• Noise level reduced by 15 dB

• Payback: 9 months

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Case Study 5: Stock Preparation Refiner Control (ACS580 Servo)

Location: Brazil
Machine: Double-disc refiner for recycled paper, 1.2 MW motor
Problem: Inconsistent refining intensity caused freeness variation; plate touching events damaged refiner plates

Solution: Installed ACS580 servo drive with high-speed torque control. Added oscillation detection – if torque spike indicates plate contact, drive trips in <10ms. Implemented load sharing between main motor and plate positioning system.

Results:

• Freeness (CSF) variation reduced by 60%

• Refiner plate life extended from 4 to 7 months

• Energy consumption reduced by 9% (improved power factor)

• Payback: 15 months

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Why Choose Inomax Technology for Paper Making?

• Decades of paper industry experience – Our engineering team includes former paper mill electrical engineers who understand speed chains, draw control, and load sharing.

• Pre-programmed macros – Select “Paper Machine” macro and the VFD is ready for speed chain configuration.

• Retrofit expertise – Drop-in replacements for Siemens (Simovert), ABB (old ACS800), Mitsubishi, and Toshiba drives.

• Global support – 24/7 remote diagnostics and on-site service for critical paper machine breakdowns.

• Complete portfolio – From 1.5 kW auxiliary drives to 50 MW main section drives, we cover all paper machine power needs.

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Frequently Asked Questions

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Q1: How do I set up a speed chain with draw control on a paper machine using ACS880 VFDs?

A: Using ACS880 AFE drives, the speed chain is configured via the built-in D2D (Drive-to-Drive) link or over Profinet IRT. Step-by-step:

1. Set master drive (usually reel or last dryer): Parameter 20.01 = Master, 20.02 = D2D or Profinet.

2. Set follower drives: Parameter 20.01 = Follower, 20.03 = Draw reference from master.

3. Program draw values: Use parameter group 20.10–20.20 for draw percentage per follower. Example: Press section draw = +0.5% (stretch).

4. Enable online draw trim: Map analog input or fieldbus to parameter 20.15 Draw trim. Operators can adjust ±0.5% during production.

5. Validate: At low speed, measure roll speeds with tachometer; adjust draw until sheet tension is consistent.

ACS880 supports up to 64 drives in a speed chain with <1μs synchronization using Profinet IRT.

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Q2: How do I implement load sharing on a press section with multiple ACS880 drives on the same roll?

A: Use master-follower torque control:

• Master ACS880 runs in speed control (parameter 19.01 = Speed control).

• Follower ACS880(s) run in torque control (19.01 = Torque control).

• Master broadcasts its actual torque value via D2D link (parameter 20.02 = D2D torque reference).

• Followers receive torque reference (parameter 20.04 = Torque reference from D2D).

For mechanical-coupled rolls, also enable droop control (parameter 21.01 = Droop rate 5%) to prevent hunting.

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Q3: What VFD features are essential for a paper winder using ACS880 AFE?

A: The ACS880 AFE provides:

• Closed-loop unwind tension control with load cell or dancer (parameter group 40.01–40.50). Regenerative energy is returned to grid via AFE.

• Taper tension algorithm (parameter 41.10 Taper tension enable). Set core diameter, full diameter, tension at core, tension at full, and taper curve (linear/parabolic).

• Rider roll load profiling – either via analog output to hydraulic valve or using a second drive in torque control.

• Diameter calculation from line speed / roll RPM (parameter 41.01 Diameter source = Calculated).

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Q4: How do I tune the PID for a dancer-controlled unwind on a paper machine coater using ACS880?

A: Use the ACS880 built-in PID autotune (parameter 40.20 PID autotune = On). The drive performs a step test and calculates optimal P, I, D. Manual fine-tuning:

• Start with P gain = 0.5, I time = 0.5s, D time = 0.1s.

• Increase P until oscillation, then reduce by half.

• Decrease I until dancer returns to setpoint within 2 seconds after disturbance.

• Increase D to reduce overshoot (max 0.2s).

Enable feed-forward (parameter 40.35 FF gain = 0.7) to compensate for acceleration torque.

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Q5: Can I use ACS880 drives on the dryer section of a paper machine with steam-heated cans?

A: Yes. ACS880 drives are ideal for dryer sections. Special features:

• Diameter compensation for thermal expansion . Input the hot roll diameter (typically 0.2% larger than cold).

• Gear ratio storage

• Load sharing on felt rolls using master-follower torque control.

• High ambient temperature rating: ACS880 operates up to 55°C with derating; for hot dryer sections, install drives in air-conditioned room or specify liquid-cooled option.

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Q6: How do I choose between ACS880 AFE and ACS890 for a large paper machine?

A: Use this guideline:

For machines wider than 6m or speeds above 1,500 m/min, ACS890 offers better dynamic performance. For most standard paper machines (3–5m wide), ACS880 is cost-effective.

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Q7: What communication protocol is best for integrating ACS880 drives into a paper machine DCS?

A: For new installations: Profinet IRT (Siemens-based) or EtherCAT (Beckhoff-based). ACS880 supports both with <1μs synchronization. For existing Rockwell mills: EtherNet/IP with CIP Sync. For legacy systems: Profibus DP (optional module). We provide GSDML, ESI, and EDS files.

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Q8: How do I set up taper tension on a paper rewinder using ACS880 AFE?

A: Step-by-step:

1. Parameter 41.01 Diameter source = Calculated (speed/roll RPM).

2. Set 41.02 Core diameter (mm), 41.03 Full diameter (mm).

3. Set 41.04 Tension at core (N), 41.05 Tension at full (N).

4. Parameter 41.10 Taper curve = Linear (or Parabolic for large rolls).

5. Enable 41.15 Inertia compensation and input roll inertia (kg·m²) – or use autotune.

Test with a sample roll and adjust Tension at full until roll hardness is uniform.

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Q9: How do I retrofit an older paper machine from DC drives to ACS880 VFDs?

A: Our retrofit package includes:

• Motor replacement (DC to AC induction, IE3/IE4) – same mounting footprint via adapter plates.

• ACS880 AFE VFDs sized for AC motor current (typically 90% of DC motor armature current).

• Existing braking resistors reused if compatible (we check resistance/power rating).

• Speed chain replicated using D2D or fieldbus.

• Analog I/O mapping – ACS880 accepts 0–10V signals from existing controls.

Typical shutdown: 10–14 days. We provide on-site commissioning.

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Q10: What maintenance does an ACS880 VFD require in a paper mill environment?

A: Recommended schedule:

For ACS880, we offer a remote monitoring module (ACS880-RO) that tracks operating hours, fan runtime, and heatsink temperature, sending email alerts.

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Q11: Can I use MAX500 drives on a paper machine?

A: No – MAX500 is not recommended for paper machine main sections. The MAX series (MAX500, MAX600, MAX500-PV) are general purpose and HVAC drives designed for fans, pumps, conveyors, and other auxiliary applications. For critical paper machine sections (wire, press, dryer, winder, calender, reel), you must use ACS880 AFE, ACS890, or ACS580 servo because they offer:

• Faster torque response (DTC vs. sensorless vector)

• Higher overload capacity (200% vs. 150%)

• Speed chain synchronization (not available on MAX500)

• Regenerative AFE (not available on MAX500)

• Fieldbus options for deterministic control

For stock preparation auxiliaries (fan pump, pulper agitation, etc.), MAX500 can be used if performance requirements are modest – but we still recommend ACS580 servo for refiners and other precision applications.

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Q12: How do I set up a flying knife on a cut-to-length sheeter using ACS580 servo?

A: The ACS580 servo drive includes an electronic cam function. Steps:

1. Configure main web drive (ACS880) as master, broadcasting position via encoder output.

2. ACS580 receives master encoder signal (parameter 50.01 Master encoder source).

3. Set cam profile (parameter group 55.00–55.40): define knife position vs. master position over one revolution (360°). Use our free PC tool to upload a table.

4. Set cut length in mm (parameter 55.50 Cut length).

5. Enable synchronization (55.01 Cam mode = On). The knife will automatically phase-lock to the web.

Accuracy: ±0.5 mm at 300 m/min with 1024 PPR encoder.

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Technical Resources

Download our technical documentation for detailed specifications:

• ACS880 AFE Paper Machine Application Guide – Speed chain, load sharing, tension control

• ACS890 Multi-Module Drive Datasheet – For ultra-high power paper machines

• ACS580 Servo for Sheeters & Cutters – Flying knife configuration

• Paper Mill Retrofit Planning Guide – DC to AC conversion step-by-step

• Taper Tension Calculator Spreadsheet – Input roll dimensions, get parameters

 

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Ready to Optimize Your Paper Machine?

Every paper mill has unique requirements. Our engineers are ready to help you select, size, and integrate the right VFD solution – whether you are building a new paper machine, retrofitting old DC drives, or improving winder tension control.

Contact us today to:

• Request a free paper machine drive audit

• Download our Paper Machine VFD Selection Guide

• Schedule a remote demo of speed chain and load sharing on ACS880

• Get a fixed-price retrofit quote for your paper mill

Inomax Technology

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