Richard Heard, senior manager at Donaldson, a specialist in filtration products and solutions, tells Packaging Scotland about the safety issues for packaging manufacturers when using lasers for marking and coding
LASERS have transformed how many industries work, including the precision marking, cutting, and coding of products and packaging, where there is a growing application of fibre lasers. However, whether the equipment uses CO2 lasers, solid-state YAG lasers, UV lasers, or next-generation optical fibre technologies, all these processes have fume emissions at the point of ablation, some invisible to the human eye.
Fume extraction systems help filter laser-generated airborne contaminants (LGACs) from laser processes, protect valuable equipment, maintain high-quality standards and reduce downtime, all within the scope of workplace regulations.
For laser marking and coding, extraction systems filter fume and Volatile Organic Compounds (VOCs) from serialisation and component marking. This helps to preserve legibility, as extraction systems keep laser lenses free from dust that could otherwise degrade the coding or markings, and manage unnecessary downtime. Examples include food and beverage packaging and the high-speed marking of expiry dates and lot codes on pharmaceutical packaging. Extraction systems are important here to prevent the ‘ghosting’ of text caused by smoke interference, helping to maintain the required scannability for regulatory compliance.
It is vital to understand the size and chemical profile of such emissions to implement an appropriate filtration strategy. At the same time, understanding the impact of momentum on the ability of particulate to travel beyond the point of ablation requires detailed airflow analysis and a corresponding refinement of system architecture and control systems.
When considering the use of lasers or the introduction of new laser technology, it is advisable to engage an industrial filtration engineer at an early stage because of the many dynamics at play in filtration and extraction performance. The engineer can then conduct a detailed assessment of the process and materials being worked and recommend the precise extraction system design to create optimal conditions for laser performance and help return clean air to the workplace.
It’s not just fume and dust that must be considered. As fibre lasers operate at high speeds, the process sometimes generates higher temperatures than other types of laser systems, while also generating very small particles. If these are not properly controlled, particles can collect around the laser head, as well as the ducting and filters, and can be highly flammable. So, extraction systems should be maintained to keep the area around the laser free from airborne contaminants to reduce the risk of an ignition source coming into contact with flammable material before it burns out.
The inclusion of a spark reduction system can help reduce fire risks in laser processes. These are designed to prevent potential ignition sources from entering the fume extraction system by intercepting them. For example, if the temperature sensor inside the spark reduction system detects a 10°C rise above the ambient temperature, it will sound an alarm and cut power to the extraction system.
The latest generation of extraction systems are also powered by intelligent monitoring platforms. Systems now allow for two-way, real-time data streams that integrate with a factory’s local area network (LAN). This provides operators with data on a high-contrast display, giving remote visibility of extraction performance, such as airflow rates and independent status for each filter stage.This data can be downloaded via USB for analytical evaluation, supporting predictive maintenance initiatives and helping to prevent unplanned downtime, enabling fully automated manufacturing control.
To help ensure the extraction system is optimised for the specific laser process, manufacturers should consider:
1. Emission profiling: understanding the specific pollutants (e.g., formaldehyde, acrolein, or metallic nanoparticles) generated by the substrate.
2. Airflow analysis: using VOC sensors to monitor exhaust air. These sensors alert operators if chemical breakthrough occurs, to help make sure the carbon filter is replaced exactly when needed.
By combining these physical safety measures with digital monitoring, operators can configure the extraction system to operate only when the laser is active, which can help reduce energy costs and further mitigate risk.
When coding and marking packaging, effective fume extraction must be capable of capturing particulate at the point of laser ablation. With faster processing comes a requirement for technical innovation and greater filter capacity to capture airborne contaminants. This is critical not just from a workplace environment perspective, but in helping to prevent fume or dust from travelling beyond the process area and contaminating products or components and potentially causing process downtime.
*This information is provided for general guidance only and should not be considered legal, regulatory, or technical advice.
