Thermography for film weld seams

In the modern packaging industry, plastic foils are ubiquitous – whether as cereal packaging, frozen food bags, or shipping pouches. To guarantee safe transport, protection against contamination, and the shelf life of goods, these welded seams must be absolutely leak-proof. DIAS Infrared GmbH offers a highly developed system solution for non-contact temperature measurement in real time. Through the combined use of the stationary PYROVIEW thermal imaging camera and the specialized PYROSOFT Automation software, seam quality is continuously monitored during the ongoing production process.

💡Direct download: You can also find the complete technical report on this application here as a compact.

Welded seams (technically referred to as sealing seams) are created through the precise interaction of heat and pressure, causing the thermoplastic material to briefly melt and bond.

However, if the sealing temperature deviates from the target value, process-critical defects occur:

• Temperature too low: Insufficient fusion of the foil layers takes place. The seam remains unstable and prone to leaking.

• Temperature too high: The plastic burns or becomes brittle.

The consequences for manufacturers are extensive, ranging from bursting bags during transit to spoiled food due to oxygen ingress, and costly product recalls. Since conventional, contact-based sensors are far too sluggish for these fast, highly dynamic cycle sequences, non-contact infrared thermography provides the only reliable alternative for seamless inspection.

The turn-key monitoring system from DIAS Infrared focuses on the precise detection of edge or bottom seams immediately after the welding process.

 

Instead of a single-point measurement, the PYROVIEW thermal imaging camera series analyzes the complete geometry of the seam.

The PYROSOFT Automation software performs the algorithmic evaluation of the delivered infrared data within milliseconds. The system identifies and monitors the thermal signature based on three essential parameters:

• The Dimension (Width and Thickness): Verification that the thermal signature of the seam matches the specified dimensions exactly.

• The Temperature Distribution: Validation that the process-dependent minimum temperature (e.g., 50 °C / 122 °F) is kept constant along the entire length of the sealing seam.

• The Total Pixel Count: A precise mathematical measure of the energetic homogeneity and stability of the weld.

PYROSOFT Automation acts as the digital interface to industrial automation. It enables seamless integration into existing system environments and Industry 4.0 processes:

• Automated Rejection: If an error is detected – such as a seam that is too narrow – a good/bad decision is made within milliseconds. Via an integrated I/O system, the system’s PLC immediately receives the command to automatically sort out the defective product.

• Flexible Product Management: Individual parameter templates can be stored for different bag sizes or foil materials. Product changeover is carried out conveniently via click or fully automated directly through the PLC connection.

• Seamless Quality Documentation: Every measurement result can be tamper-proofed and saved on the hard drive as an IR data set, image, or log file. This secures a legally compliant proof of quality for manufacturers in the event of customer complaints.

Would you like to read about the technical details, measurement parameters, and system configurations in detail or share them with your team? Download the complete, two-page application report here free of charge:

👉 Download: Application Report “Quality Assurance of Foil Sealing Seams with PYROVIEW & PYROSOFT” (PDF)

Thermographic monitoring of welded seams with PYROVIEW and PYROSOFT Automation offers a reliable and non-destructive alternative to random spot-checks. It sustainably protects packaging operations from loss of image, reduces scrap, and ensures consistently high product quality in demanding 24/7 industrial environments.

Do you want to optimize the process reliability of your packaging systems? Our project engineers will gladly advise you without obligation on integrating industrial infrared measurement technology into your manufacturing processes.