Laser Engraving on Plastic Sheets

One reason for plastic’s popularity is its non-biodegradable, durable, and chemical-resistant properties. These characteristics call for an engraving method that lasts as long as plastic does. Fortunately, laser engraving plastic is a permanent method that withstands contamination, force, and environmental changes.

Plastic sheets are thermoplastics. Since they’re thermoplastic, plastic sheets can be remolded with the right amount of heat or pressure. Although this characteristic means that these plastics are recyclable, it also means there’s a risk of accidental deformation when engraving with an engraving bit.

However, laser engraving plastic sheets is immune to this mistake because the engraving process does not have any contact. No pressure is added to the plastic with a laser, so the plastic remains intact while engraving.

Plastic sheets are mass-produced, cheap, and easy to manufacture, so choosing laser engraving is keeping up with the cost-effective industry. Laser engraving can add a mark in a fraction of a second and is exceptional at repetitive tasks. Also, there are no consumables like ink or tips so the running cost of a laser engraver is virtually nothing.

UV laser markers use a 355 nm ultraviolet wavelength generated from a 1064 nm wavelength passed through two crystals.

The 355 nm wavelength leads to significantly higher absorption and therefore can mark plastics through a photolytic degradation process. This process causes the breaking in bonds without relying on the heat effect that other lasers rely on. The strength surpasses surface level solid to liquid effects and does not add any heat.

Because no heat is used, this method is called “cold marking.” Cold marking is especially ideal for plastic because it prevents the plastic from deforming or developing burrs.

A hybrid laser combines a YVO₄ and a fiber laser as one unit with a 1064 nm wavelength. Together, the single laser has a long service life with high output and deep engraving capabilities. The combination of the 1064 nm wavelength and hybrid technology generates a very high peak power which can engrave plastic with very minimal heat transfer.

CO₂ laser markers use a 10600 nm wavelength and rely heavily on the heat effect. Due to the longer wavelength, CO₂ lasers use heat to engrave plastic with depth very quickly.

Semiconductor devices frequently use plastic sheets as a packaging material because of their resistance to contaminants, moldability, and low cost. Plastic sheets protect semiconductors from contaminants such as mold, acid, and mildew. Additionally, the moldability of a plastic sheet means that it is compatible with the uniqueness of each semiconductor. Finally, the low price of plastic sheets means that semiconductors are protected at a low cost.

Since semiconductors are used in a plethora of applications and can sometimes include hundreds of tiny components, semiconductors need plastic laser engraving for traceability and identification marks. Laser engraving gently engraves semiconductor plastic packaging with a number, barcode, or logo for easier supply chain tracing, faster recalls, and better quality assurance.

The cabin interiors of aircraft benefit from plastic sheets because of their durability and low weight. Plastic sheet components withstand sanitation and food and drink spills. Window plastic sheet layers withstand pressure and temperature changes.

The aircraft industry requires marks for traceability and safety purposes, so laser engraving is an ideal method for these marks. The durability of laser engraving is equal to that of a plastic sheet aircraft component. Regardless of the change in temperature, pressure, sanitation, or contamination, the engravings will remain.

These engravings assist passengers by being permanent and high contrast markings that give safety instructions. For manufacturers, the plastic laser engraving serves as traceability marks to recall defective components and trace components through maintenance checks.

Medical tray sealing is a common practice for packaging medical devices that need extra sterilization and transportation protection. These medical devices, usually medical implants, carry extreme risk of contamination or movement in a clamshell or blister packaging. The tray seal prevents the device from moving during shipping and exposure to contaminants.

In the medical industry, the FDA requires all medical devices (besides class 1 commercial devices) to have a unique device indicator (UDI). A UDI is a 2D code that stores traceability and usability information about the device. It’s required to be permanent and readable by humans and robots. Laser engraving is perfect for adding a UDI onto medical tray sealing. The no-contact method prevents any damage to the seal, and the permanency ensures the UDI meets federal regulations.