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Integrating automotive traceability into stamping with laser marking

Allows individual part ID, meets automotive OEM traceability requirement

Laser marking

Laser marking can help stampers overcome some of the challenges of meeting part traceability in a stamping process for the automotive industry.

Metal stamping manufacturers are predominant suppliers to the automotive industry for good reasons. Stamping technology offers many benefits in terms of lead time to market, cost, and lean manufacturing. Once the dies have been built, stampers make high-volume automotive parts at a low cost per unit.

However, International Automotive Task Force (IATF) guidelines and certifications are becoming increasingly challenging to meet. They require automotive stampers to upgrade their installations to comply with tighter traceability standards.

The Challenges of Automotive Traceability

To satisfy current automotive OEM traceability requirements, metal stampers need to identify parts at the very beginning of production. The coil or sheet must be marked just before it is stamped or immediately after so that the part is traceable to the material.

This provides traceability by linking the part to the raw material and the stamping press used to make it. To be effective, the marking operation must be integrated with the stamping press, but this creates challenges:

  • Speed. One of the biggest challenges is ensuring that the marking can happen accurately at high speeds to keep up with production volume. The marking operation must be able to keep pace with the high speed of the stamping press.

  • Harsh Environment. Lubricants used to facilitate forming of stamped parts create a harsh environment for the marking system. During marking, the oil released into the air can contaminate the marking system and reduce its efficiency.

  • Coated. Many stamped vehicle parts are coated downstream—either powder coated or electro-coated and painted—to make the parts resistant to corrosion in harsh operating environments and to make them more attractive. Coatings, especially thick coatings, can interfere with the identifiers’ readability. Even a thin coating can ruin the identifiers’ contrast and compromise traceability.

Meeting Marking Challenges

To ensure that the markings are readable, stampers must generate high-contrast identifiers to guarantee traceability, even on oily surfaces or when oil is in the air

Many stampers choose to stamp a batch number on the formed parts, but the number is only changed between batches. This helps correlate parts to batches but not to the entire production pathway. Because a batch can be large, it can include an entire day’s worth of production and thousands of parts. That can translate to an entire day’s worth of scrap if a defect occurs.

The automotive industry has seen more than its share of recalls over the past few years. According to an Allianz report, insurance claims for recalls in the automotive industry can cost millions of dollars per incident. If there is a quality problem or a recall, it gets complicated—and expensive—quickly because of the volume of parts involved.

A better way to manage traceability is to track every part with a unique identifier. Being able to trace a defect to an individual part can simplify the process and greatly reduce the amount of scrap generated. This is possible using laser marking.

Laser Marking Single Parts

Laser marking is a versatile technology that can be used to mark parts formed from all types of metals including aluminum, carbon steel, and stainless steel.

The laser can be integrated into the stamping process either to mark the sheet metal right before the part is stamped or just afterward.

Laser marking can generate a unique data matrix code for each stamped part for complete traceability. Not only do data matrix codes allow for tracking each part to minimize recalls, but they also tend to have better readability rates than other types of identifiers. This significantly reduces the amount of scrap.

Laser marking a unique data matrix code overcomes other challenges inherent in the production process:

  • A 100-W pulsed fiber laser can etch a data matrix code every second, so keeping up with the high speed of the stamping press is usually not a problem. If this poses a speed limitation, more powerful lasers can be used. However, there might not be a solution for all applications.

  • Laser markers can generate identifiers on oily surfaces, which often is the case around the stamping press.

  • A data matrix code can remain readable at up to 30% damage, thanks to the error-correction algorithms used by bar code readers.

A metal stamping environment can be harsh. Low-quality lasers will not perform well in these conditions. When etched by a laser, an oily surface releases oil particles into the air. Lasers with low ingress protection (IP) ratings for dust and liquid resistance will not manage contact with oil well. In choosing a laser marking system, make sure it has a sufficient IP rating to handle your environment. A fume extractor to capture dust and fume can help mitigate the problem.

Readable Through Coatings

Parts stamped for the automotive segment are typically e-coated or powder coated. While stamped identifiers are usually deep enough to maintain their readability through the coating, shallow, laser-marked identifiers may not be deep enough to read through coatings.

It’s important to use a laser marking technology that ensures marks are readable through the coatings. This is essential to manage traceability. You need a laser marking system that can engrave identifiers and maintain a good contrast for readability after the coating process. The best practice is to use a special laser engraving process with a custom cell size for the data matrix code.

Laser engraving does take a little longer to complete, so this may pose a challenge to inline integration, depending on the available cycle times. Using a high-powered, 300-W pulse-fiber laser can solve this challenge, even for short cycle times.

Meet Production Goals Worry-free

Manufacturing automotive parts often involves multiple processes performed in different plants, from stamping to coating to assembly. Each may use different code systems. Because metal stampers are at the start of the manufacturing and assembly process, traceability starts with them.

To enhance traceability, each process a part goes through should use the same codes from start to finish. That’s why so many automotive OEMs require their part suppliers to use laser technology. Laser marking is a technology that can meet their stringent requirements.

A robust laser marking system provides a feasible way to meet OEM requirements, comply with IATF guidelines, and meet the traceability challenges demanded in today’s marketplace. Using laser marking, stampers can focus on meeting daily production goals without worrying about costly recalls.

About the Author

Keven Tremblay

Application Specialist

2811 Avenue Watt

Québec, G1X 4S8 Canada