“Pre-registration” means one thing on the shop floor: the press finds color alignment before it starts printing, not during. No inline adjust-and-waste cycle. The plate cylinders are mechanically aligned using pre-mounting scales and calibrated adjustment rollers — then the press runs up to speed with registration already locked in. Here is how it works in practice and why it cuts more waste than any other single upgrade on a gravure line.
The Pre-Registration Workflow: Five Steps
- Substrate must be tension-stable with no stretch. Pre-registration assumes the web enters each print station at a predictable length. If the substrate is stretching under tension, all pre-alignment is meaningless. Verify tension control before starting.
- Use the pre-mounting scale to align cylinders. When changing plate cylinders, align each one using the pre-mounting scale against the registration marks engraved on the cylinder body. This is a mechanical step — no electronics involved — and sets the baseline alignment.
- Set the scaled adjustment rollers per manufacturer spec. Before registration runs, the graduated adjustment rollers must be positioned according to the press manufacturer’s specification. This establishes the correct web path and initial registration window.
- Match impression roller circumference across all color stations. All impression rollers in a multi-color press must have identical circumference. Use the manufacturer’s specified roller dimensions. Before auto pre-alignment starts, input the exact plate cylinder circumference into the control system.
- Complete transverse alignment and longitudinal addressing before auto-ramp. Before engaging automatic speed ramp and registration control, manually set transverse alignment and complete longitudinal addressing. Only then does the press accelerate into full-speed printing with registration already established.
Six Technical Advantages
1. Minimal web length change during impression engagement. When impression rollers engage and disengage across different cylinder diameters, the pre-registration system maintains near-constant web length. The result: less material waste on every start-up and faster automatic registration lock.
2. 1 mm/sec registration motor precision. Each complete revolution of the registration stepper motor changes the web path by 1 mm in material length. The registration computer processes position data rapidly, and the leadscrew-driven web path adjustment produces zero mechanical hysteresis. Registration lock time is short, and waste during lock-in is minimal.
3. Fine-pitch gear mesh on shaftless cylinder boxes. The shaftless cylinder mounting system uses small-module clutch gears with fine tooth pitch. Rotation variation during engagement is minimal, positional precision is high, and pre-alignment with the mounting scale is fast.
4. Elimination of on-press cylinder positioning. Pre-mounting eliminates the need to engage and disengage shaftless gearboxes or cycle impression rollers up and down to align cylinders during production. This cuts non-printing auxiliary time, saves material, and improves overall equipment effectiveness.
5. Off-press longitudinal addressing. Auto pre-alignment allows longitudinal registration addressing — the process of moving the leadscrew up and down to adjust web length between stations — to be completed without the press running. This eliminates the waste that normally accompanies initial registration lock-in and saves time on every job change.
6. Built for short-run economics. As the print market shifts toward higher variety and smaller batches — with multiple cylinder changes per shift — pre-registration presses show their strongest advantage. They effectively eliminate the practice used by smaller converters of running narrow test material for registration, stopping to inspect, then splicing in production material and restarting. The press goes from job change to production print with essentially zero registration scrap.
References
- Wikipedia: Rotogravure: Foundational overview of gravure printing technology including registration control systems and shaftless drive architecture.
- Wikipedia: Printing Registration: Explanation of registration principles, error types, and automated correction methods in multi-color printing.
- Wikipedia: Stepper Motor: Technical reference for stepper motor precision, positional accuracy, and control systems used in registration drives.
- ISO 12647-4:2014 — Graphic Technology: Gravure Printing: International standard for process control and print quality parameters in gravure.
- Flexible Packaging Association (FPA): Industry association providing technical resources and best practices for flexible packaging converters.