April 8, 2022
(press release)
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Using lasers to add permanent and durable marks, such as serial numbers or barcodes, to plastic parts and products makes it easier to reuse and recycle materials - creating a more circular economy. Living in a world without plastic, or synthetic organic polymers, seems unthinkable today. Plastics are included in hundreds of products that we use in our daily lives - from motor vehicle parts, food packaging, medical supplies, and sports safety gear to computers and cell phones. The large-scale production and use of plastics started in the 1950s. Since then, there had been an estimated 8.3 billion metric tons (Mt) of plastics produced worldwide [1]. But none of the commonly used plastics are biodegradable - and as a result, they can persist in our environment for decades. As of 2015, around 9% of plastic waste had been recycled, 12% had been burned, and the remainder end up in landfills or the environment [1]. If current trends continue, approximately 12,000 Mt of plastic waste will be in landfills or the environment by 2050 [1]. The world needs to adopt more sustainable ways of dealing with these man-made materials. “We need to shift to a circular economy where plastic products are in use for longer - and the materials are reused to manufacture new products,” says Silvia Rosenberger, our Technical Marketing Manager. Product identification is a key enabler for circularity - providing the ability to track and trace any plastic item - such as a car part, medical device or food package - over its entire lifetime. “Imagine a world where everything can be used again,” says Ulrich Quittman, our Laboratory Manager for Application Technology. “But in order to use something again or recycle it, you first need to know what it is - and that will only be possible if each individual product has a unique identification.” DID YOU KNOW? 12000 metric tons of plastic waste predicted to be in landfills or the environment by 2050 [1]. 1960 saw the creation of the first working laser. A NARROW BEAM WITH BROAD USE The basic premise of the laser is simple - consisting of a tube that concentrates light repeatedly until it emerges in an intense, narrow beam. A laser generates light of a single wavelength or monochromatic color - which is often bright red or green, or an invisible ‘color’ such as infrared or ultraviolet. Importantly, the light waves are exactly aligned in their direction, frequency and are all in phase both in space and time. It’s this combination of properties that make lasers precise, powerful and incredibly useful beams of energy. The energy released is measured in wavelengths or nanometers - the higher the wavelength, the more powerful the laser beam. Whether we realize it or not, lasers are now integrated into many areas of our everyday lives. They have an incredibly diverse range of applications - including in optical disc drives, printers, barcode scanners, laser surgery, cutting and welding, and even carrying high-speed internet signals through fiber-optic cables. But perhaps one less well-known application for laser technology is for the labeling of plastic parts and products to enable their identification. Clean Meat LIGHT THAT STAYS “The material itself has become the mark,” says Rosenberger. “There is no abrasion, and better adhesion - so it can’t fall off - and you can’t wipe it away.” Although it is possible to laser mark virtually any type of material - plastics require an extra ingredient. “Adding a small amount of a laser-sensitive pigment into the plastic material gives it the capability to change color when exposed to the laser,” explains Quittman. “That’s how the laser writes directly onto the plastic, it’s an entirely contact-free process.” Our Iriotec® 8000 series of pigments and granules offer two solutions for fast, consistent durable laser markings. “Our powder pigments convert laser light to heat, changing the polymer itself. The laser light heats up the polymer chains in the plastic very strongly - and as a result, the exposed carbon is visible as dark markings,” explains Quittman. “Through foaming, the carbon in the plastic oxidizes and forms gas bubbles - and this results in a foam layer of light markings.” “In contrast, the granulated pigments change color themselves, making the marking separate from the polymer matrix. Each of the granules contains an absorber and a color former. When absorbing laser light, the absorber stimulates the color former resulting in precise dark markings,” he adds. Unlike other marking processes - such as inkjet printing or stick-on labels - direct laser marking requires no consumables, such as solvent-based inks or adhesives. Manufacturers can also benefit from reduced downtime on the production line. “There’s no setup time needed because it’s the light that’s doing the reaction in the material,” explains Rosenberger. “So from the moment you switch on the laser, you can create products that you can sell.” PERMANENT IDENTIFICATION “For example, the UDI is used on medical devices to ensure traceability and patient safety,” says Rosenberger. “And the QR code is becoming increasingly popular, it’s like a digital product passport that may link to a website, database or application containing important information about the item.” The technology is widely used for applications requiring durability and permanence. A common example is laser marked plastic ear tags, which are widely used in agriculture for animal identification. “For example, in many countries, it’s a legal requirement to have ear tags on cattle to meet strict requirements on identification and traceability,” says Quittman. “For obvious reasons, these need to be highly weather-resistant and protected from environmental influences like abrasion - and the material needs to be very flexible, so it doesn’t hurt the animal’s ear.” Laser marking is also widely used to mark codes or technical information onto plastic electronic and automotive parts, electrical cables and wires. “We also have many customers in the food and drinks industry,” says Quittman. “They may want to use the technology for clean marking of expiration dates and batch numbers on food packaging - or even to put the game codes inside their soft drinks bottle caps.” The technology is very flexible and can be miniaturized for labeling small parts - or used to mark the inside of curved surfaces that would otherwise be extremely difficult to reach. “For instance, a laser can be used for high contrast marking on transparent products - such as to mark scales inside pharmaceutical and medical jugs, cups and beakers,” says Rosenberger. BEAM US INTO THE FUTURE Many manufacturers are taking greater responsibility for the plastics in their products - and better identification is key for improving the sustainability of these long-lived materials. “We want to see more and more plastic parts and products laser marked so they can be easily identified,” says Rosenberger. “In the end, we will have a much more sustainable world where we use plastic materials for much longer and have the ability to recycle it even after many years. I think that’s what the future is.” OUR CONTRIBUTION LEARN MORE ABOUT SDGS REFERENCES
8.3bn metric tons of plastics had been produced worldwide by 2015 [1].
In 1960, the physicist Theodore Maiman produced a new kind of light, not found in nature. For the first time, he had managed to coax the atoms in his new device to emit their light in a coordinated way, in what is known as stimulated emission. He had built the first operating LASER - which stands for “Light Amplification by Stimulated Emission of Radiation”.
In simple terms, laser marking uses a focused beam of light to create a lasting mark on a surface of a material. When the beam interacts with the material, it alters its properties and appearance - creating precise, high-quality marks that are easy to read or scan.
Laser marking systems are ideal for enabling the identification of plastic parts or products - such as by using serial or part numbers, data-matrix codes, unique device identifiers (UDI) or quick response (QR) codes.
Whether it’s for animal ear tags, food packaging, or electrical components and cables, we provide a laser marking service where we work closely with each customer to help them find the right solution for the best results.
“We provide support for laser marking to our customers all over the world,” says Quittman. “They send us their samples for testing - and we will also go to visit their production lines to help support them with the development of their programs.”
In 2012, the United Nations set out 17 Sustainable Development Goals (SDGs) that meet the urgent environmental, political and economic challenges facing our world. Three years later, these were adopted by all member states. We are committed that our work will help to achieve these ambitious targets. Sustainable laser marking fits under ‘Goal 12 — Ensure sustainable consumption and production patterns; Target 12.5— substantially reduce waste generation through prevention, reduction, recycling and reuse.’ Seizing new opportunities from laser marking has the potential to revolutionize our relationship with plastic materials by encouraging greater reuse and recycling.
[1] https://www.science.org/doi/10.1126/sciadv.1700782
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