How flying marking works
In an online setup, the galvo marking head is fixed over the line and the product moves under it. A sensor detects each product and sends a start signal. An encoder on the conveyor reports the line speed, and the marking software shifts each stroke in step with the movement, so the text comes out straight and evenly spaced even though the product never stops. This is called flying or on-the-fly marking. It also needs a steady conveyor: belt slip or vibration shows up directly as stretched or wavy characters, so the encoder should measure the conveyor itself rather than the drive motor.
The time available to mark is set by how long each product stays inside the marking field. A short code on a slow line is easy. A long block of text on a fast line may need a larger field or a shorter code. Some lines use stop-and-mark instead, where an indexing conveyor or a fixture pauses the part under a static head. That is simpler to set up and still counts as inline marking.
Which laser for which line
Fiber suits metal parts and many engineering plastics on assembly and machining lines, for example marking gears and connectors as they pass a station. It is also used on cable and pipe extrusion lines where the jacket or pipe material is laser-markable, such as some polyethylene grades made with laser-marking additives.
CO₂ suits packaging, including labels, cartons, PET bottles and paper-based packs, and it is the common choice for laser coders on food and consumer goods lines. UV suits fine codes on heat-sensitive plastics and cable jackets where the mark must not melt the surface. The CO₂ laser marking machine and UV laser marking machine pages explain those sources.
Where a product cannot be laser marked, PVC cables and pipes being the usual case because PVC releases hydrogen chloride gas, continuous inkjet is the standard alternative. The Markem-Imaje CIJ printers page covers that route.
Linking the marker to your line and data
An online laser marking machine is only as good as its integration. The basics are a product-detect sensor and an encoder for line speed. The controller also exchanges status signals with the line PLC, such as ready and fault, so the line can stop or divert products if marking fails.
Beyond that, most plants want the marking content to come from the line: batch and shift codes, the date, serial numbers from a counter or database, and a different layout for each product type, loaded by recipe. Many lines add a camera or code reader after the laser to check every mark and reject products with unreadable codes. Fume extraction at the head is needed on plastics and packaging, and the beam path needs guarding where the head sits over an open conveyor, so plan shields and interlocks with the line builder.
What to check before you buy
- Line speed and pitch. Give the maximum line speed and the gap between products. Together these decide how much can be marked on each product.
- Mark content. List the longest code or text block, including any 2D codes. Long content on a fast line is the most common limit.
- Material at speed. Test the actual substrate at line speed, not just a static sample on a bench.
- Mounting. Plan the head position and a way to adjust its height when product sizes change between batches.
- Communication. Confirm the controller supports the signals and data link that your PLC or MES uses.
- Verification. Decide whether a camera or reader will check each code, and where rejected products go.
- Environment. Dust and oil mist on the line affect the optics. Ask about head sealing and how easily the lens can be cleaned.
- Guarding. Guard the beam path over open conveyors with shields and interlocks, and keep extraction close to the mark.
NMB's online marking options
NMB Enterprises is an authorised distributor of IndoForeign Technologies laser systems, and the On-line Fiber Laser in that range is built for flying marking on production lines. For packaging lines, NMB also deals with Markem-Imaje coding and marking systems, including the Markem-Imaje laser coders. Bench models for offline batches are covered on the fiber laser marking machine page, and the full range is on the products page.
Online laser marking machine in Tamil Nadu
Production lines across Tamil Nadu suit an online laser marking machine. Automotive and component plants in the Sriperumbudur and Oragadam belt and around Hosur need traceability codes on parts such as brake pads and wiper motors, which an inline station can apply without slowing assembly. Pump and motor makers in Coimbatore can mark motor housings and pump parts as they move between assembly and testing.
In Chennai, engineering units in the Ambattur and Guindy industrial estates can add a marking station to existing assembly lines. Buyers outside Chennai can phone or WhatsApp NMB on 098417 60722 with photos of the product and the line speed, and NMB will suggest an online laser marking machine or coder to suit. NMB is based at Poonamallee, Chennai 600056.