Laser Marking on Plastic

ABS plastic creates excellent contrast with UV marking. The material darkens under laser exposure, producing readable black marks on natural-colored surfaces. ABS components in automotive and consumer electronics benefit from this high-contrast marking capability.

PET, or polyethylene terephthalate, responds well to UV wavelengths for both clear and colored variants. Bottle caps, packaging components, and food containers marked with UV lasers maintain FDA compliance standards. The marks resist common cleaning chemicals and dishwasher cycles.

Polycarbonate offers outstanding mark quality with UV systems. This engineering plastic produces sharp, permanent marks suitable for optical components and safety equipment. The transparent nature of polycarbonate allows for internal marking applications where surface aesthetics matter.

Nylon varieties work well with UV lasers, as they leave light-colored markings on dark materials. This reverse-contrast capability is useful for mechanical parts, cable ties, and industrial components. Even after prolonged exposure to the outdoors, the markings are still discernible.

Polyethylene and polypropylene require specific UV laser parameters for optimal results. For typical IR lasers, additives are frequently required for these plastics in order to generate high contrast marks. However, when set up correctly, UV systems leave long-lasting, high-contrast marks with no need for additives.

Laser systems cost more upfront but save money in the long-term. Traditional methods need constant supplies like labels, ink, and replacement parts, while lasers only need basic maintenance and lens cleaning. Plus, lasers have fewer moving parts, so they break down less often than label machines that jam frequently.

Lasers are much greener. Traditional marking creates tons of waste from label backing, empty cartridges, and misprints. Lasers produce zero waste and don't need shipped supplies. Laser-marked products are also easier to recycle since there are no sticky labels to peel off.

UV lasers are used for laser marking plastic because they mark with a process called “cold marking.” Because they operate at a much shorter wavelength than standard lasers (355 nm vs 1064 nm), they are able to process the surface of the material without heat. This provides a higher level of contrast without any damage to the material.

Hybrid laser marking machines use a combination of a YVO₄ laser and a fiber laser for laser marking plastic. Together, these lasers make a 1064 nm wavelength with a short pulse and 200kW peak power. The drastically higher peak power allows for high-quality marking without the thermal damage that often results from a standard fiber laser.

CO₂ laser markers use a high level of heat to “melt” the surface of materials, creating a raised or etched mark. This method does not rely on color contrast but provides durable, permanent marking on plastic in addition to wood, ceramic, and other materials. CO₂ laser marking is commonly used for product branding and identification across a range of industries.

Optimizing laser marking on plastic requires a multifaceted approach, starting with precise parameter optimization. This involves thorough material testing to account for varying reactions of plastic compositions to laser settings. That translates to adjustments to power levels, pulse frequencies, and scanning speeds. Sample testing prior to production ensures optimal parameters are established.

Beyond laser settings, surface preparation is paramount for superior mark quality. Clean surfaces, free from oils, dust, and static charge, yield the best results. Eliminating contaminants that can interfere with the light interacting with the part is important, but can often be removed by the laser itself with cleaning passes before marking. Proper fixturing is also crucial to prevent part movement during the marking cycle.

Effective ventilation systems are essential for managing marking byproducts. While UV marking produces minimal smoke compared to thermal processes, proper extraction is vital for maintaining air quality. Certain plastic types may release specific vapors that necessitate specialized filtration systems.

Throughout production runs, quality monitoring systems are integral for verifying mark characteristics. Vision systems can assess completeness, dimensional accuracy, and contrast levels. Furthermore, statistical process control can detect parameter drift proactively, preventing quality issues before they arise.

Lastly, consistent mark quality and laser performance can be achieved via comprehensive maintenance plans. Regular cleaning of optical components preserves beam quality, and routine calibration checks confirm accurate placement and stable power output.

Considerations for glass marking applications are comparable to those for plastic processing. The advantages of UV wavelengths and accurate parameter control are advantageous to both materials.

An important development in permanent identification technology is the switch from conventional labeling to laser marking. As system capabilities advance and costs come down, laser engraving capabilities keep growing.
Understanding laser etching fundamentals helps operators optimize their processes for specific applications. Each marking scenario presents unique challenges that benefit from systematic approach development.
Plastic marking solutions address diverse industry requirements while maintaining cost-effectiveness and production efficiency.

Peel the paint or printing on the target surface to bring out the contrast with the color of the base material.

(Example) Automobile instrument panel switch
Paint peeling has risen in popularity due to its simplicity and convenience. For one, conventional methods (like printing and stamping) require full plate changeovers when a design change occurs. With a laser marker, you can adjust layouts by simply changing the program. For example, in the panel switch example above, if the manufacturer wanted to print on top of the panel switch, it would require custom printing plates. Laser marking makes this task easy, as it simply peels the paint off, saving both time and money.

Remove/engrave the surface layer with a laser.

(Example) Half cut
Surface layer peeling helps expose the hidden materials beneath our everyday layers, like paint, aluminite, and more. By removing these coatings with this process, a grounding point is created to better access what lies underneath. This enables new possibilities for creativity or problem-solving when it comes to marking on plastic surfaces.

A laser marker can be used to easily process a cutting section. Physical cutters are conventionally used in these scenarios but are difficult to adjust and time-consuming to change. Moreover, physical blades must be replaced often (incurring hard costs), and there's a risk that the blade will come loose and get left in the product.

Irradiate a plastic target with a laser to develop a color in the target itself.

(Example) Wide-area marking on LSI
Color development is used to create beautiful, vivid colors on plastic targets without causing any damage or engraving the material. This common technique allows for personalized customization with creative and unique designs. Using laser radiation to develop a color instead of engraving the plastic minimizes damage from marking the target.

Use the heat of laser radiation to weld and join plastic parts.

(Example) Welding of transparent plastic and colored plastic
Laser radiation welding offers a reliable and efficient way to join plastic parts, with the added benefit of no vibration, which could negatively affect the product's quality. Without making contact during the process, delicate products remain untouched, eliminating any potential imperfections or damages that may occur due to burrs.

Whatever techniques are chosen, laser marking adds clarity, precision, and visibility, making it an ideal choice for long-term results in plastic applications.