Edge guiding
Use the material edge as the reference when maintaining a repeatable edge position is the relevant production requirement. Confirm the edge stays inside the sensor's usable detection range during normal operation.[3]
Resources / Web Guiding for Printing
Web Guiding for Printing Lines: Setup and Selection
Web guiding on a printing line is a lateral-position control task: define what the sensor should follow, verify the correction mechanism, and commission the complete web path under the materials and speeds that matter.
Printing application guide
Guide the process reference that the print line actually needs
For printing and converting, sensor choice and guide location should follow the material, the required reference, the available correction travel and the real mechanical web path.
What web guiding controls on a printing line
A standard web-guiding loop measures a web position, compares that feedback with a reference, and adjusts a steering frame or actuator once the difference exceeds the configured dead band. That is the control-loop function; the printing process still needs its own registration, tension and mechanical checks.[1]
In roll-to-roll printing research, cross-machine register error is modelled as a lateral positional deviation between printed patterns at different stations, with web lateral displacement and roller misalignment identified as important contributors. This is evidence from a flexible-electronics printing context, not a universal accuracy claim for every press.[2]
Centre guiding
Use a centre reference when the process needs the web centreline held relative to the machine. The sensor arrangement and reference definition must match the chosen mode.[3]
Line or mark tracking
Use a printed line or mark only when that feature is a reliable, intentionally selected process reference. Verify contrast, surface condition and mark geometry on the actual production material before specifying the sensing method.
Where to place the guide
The guide location should be selected from the web path and the process reference that must remain stable, not from a generic before-or-after rule. For a particular steering-frame arrangement, the manufacturer manual places material sensors downstream of the steering frame in the running direction; confirm the documented arrangement for the selected equipment and machine geometry.[1]
KRD engineering guidance is to map the unwind, infeed, print, inspection, laminating, slitting and rewind zones, then identify where lateral position first matters to the quality requirement. A guide cannot compensate for roller alignment, material deformation or tension instability elsewhere in the path without verification.
Selection and commissioning checklist
- Define the tracking target: material edge, centreline, printed line or contrast mark. Describe the acceptable position error in the context of the printing and finishing operation.
- Record substrate type, web width, thickness, transparency, surface condition, line speed range, roll diameter range and the section where the deviation first appears.
- Verify sensor alignment and detection range with the actual web. The BKS309 manual describes aligning the web edge through the sensor axis, the centre of the active window, for its sensor arrangement.[1]
- Check steering-frame or actuator direction, available travel, limits, mechanical play and the relationship between correction movement and the observed web response.[1]
- Commission at controlled speed and observe the sensor signal, reference, correction direction and downstream process result together. Do not tune a controller around an unverified mechanical or material problem.
What web guiding does not solve by itself
Web guiding addresses lateral position around its selected reference. It does not by itself establish longitudinal registration, correct every printing defect, or remove the need to control tension, roller alignment and material condition. In roll-to-roll polymer-film research, roller misalignment and side-to-side tension differences are associated with accumulated lateral error; use that evidence as a diagnostic prompt rather than a substitute for inspecting the machine.[4]
For a retrofit, separate the observed symptom from its suspected cause. Record whether wandering changes with roll diameter, acceleration, material batch, speed, print station or downstream tension zone. That record helps determine whether a web guide, a sensor change, a mechanical correction or a broader controls review should be evaluated first.
How KRD supports printing projects
KRD Automation reviews the web path, material, speed range, control zone, installation space and required process reference before suggesting a product family to evaluate. Drawings, photos and short videos help reveal sensor mounting, actuator travel, roller layout and panel-interface constraints.
Relevant starting points may include an EPC controller, suitable edge or line sensing, and a steering-frame or actuator arrangement. Final selection and commissioning should be confirmed against the real machine, material and production acceptance criteria.
Sources & References
- FMS Technology. Operating Manual BKS309.MS Back
- International Journal of Precision Engineering and Manufacturing-Green Technology. Quality-Assured Roll-to-Roll Flexible Printed Electronics: Defect-Robust Register Sensing and Alignment Correction Back
- FMS Technology. Operating Manual BKS015 Back
- Polymers. Sensor-Efficient Estimation of Roll Misalignment via Side-to-Side Tension Differences in Roll-to-Roll Polymer Film Processing Back
FAQ
Does web guiding replace print registration control?
No. Web guiding controls lateral web position around a selected reference. Print registration also depends on the process, register sensing, machine mechanics, tension and commissioning.
Should a printing line follow an edge or a printed mark?
Choose the reference that matches the production requirement. Verify the actual material, mark contrast, sensor suitability and mechanical correction path before finalizing the method.
What should be checked before a web-guide retrofit?
Document the web path, material, speed, affected zone, available mounting and actuator travel, existing sensor signal, tension conditions and the specific production symptom.
Plan a web-guiding retrofit for your printing line
Share the material, web width, line speed, web path and the position or registration symptom. KRD can help identify the control and sensing components to evaluate.