Marking of plastics with lasers

Plastic engraving, or laser marking, is the process of marking or labeling plastic components using a laser. Plastic parts are made of polymers that dictate how they are laser cut and the amount of energy needed. There is a significant connection between the type of plastic, dyes, and type of laser when it comes to the result of laser marking. Non-contact laser marking involves absorbing the laser beam by the plastic. Plastics are also laser welded using this behavior, where one welding partner absorbs the laser beam and the other is transparent to it.

Laser marking is possible on a wide variety of plastics and thermoplastics. In the event that a plastic’s properties prevent laser marking, a suitable additive or masterbatch for plastic laser marking can typically be added to modify its properties. Laser marking can also be influenced by additives such as color pigments.

LASER MARKING AVAILABLE IN MANY FORMATS

Due to their high reliability and numerous benefits, laser marking is becoming increasingly popular in industrial applications. Moreover, laser marking is forgery-proof and extremely robust. A high-quality application is also possible.

As an alternative to conventional marking technologies, plastic laser marking offers the following advantages:

  • The permanent marking properties include waterproofness, wear- and heat resistance, lightfastness, and chemical resistance
  • Marking design with maximum flexibility – suitable for difficult-to-access locations
  • With a non-contact process, there is no wear and tear on tools and no consumption of consumables like chemicals, ink, etc., so consistency can be assured.
  • The surface is unimpaired (color changes)
  • Handling is easy, no pretreatment or post treatment is required

There are several types of lasers

By exposing plastics to laser beams, laser marking changes the optical surface of the plastics. There are various laser media used here, and each generates the laser differently. Lasers can be classified as gas, dye, or solid-state.

 It is not only the type of laser that influences the result when lasering plastic, but also the wavelength. CO2 lasers, fiber lasers, and Nd:YAG lasers are ideal beam sources for laser marking applications.

At Ensinger, solid-state lasers have been tested successfully. Practice also frequently uses this laser.

Lasers made from yttrium aluminum garnet and neodymium are called Nd:YAG lasers. A YAG crystal doped with neodymium serves as its active medium. In addition to being the most frequently used wavelength, 1064nm produced the best results.

APPLICATIONS

Conventional printing methods are increasingly being replaced by laser marking. The use of lasers for marking plastics has become increasingly common. Traceability and quality assurance have become increasingly relevant. In order to uniquely identify plastics, bar codes, articles, and batch numbers are frequently applied to them. It can be applied to a wide variety of applications across a wide range of industries. Among them are:

  • Components of the casing made of plastic
  • Components of electronic equipment
  • A circuit board for a car
  • Tool handles and tools

LASER MARKING SUITABLE PLASTICS

There are some high-performance plastics that cannot be laser marked intrinsically. NdYAG lasers, for example, do not usually change the color of POM (acetal) or polyamide PA without modification. For this reason, Ensinger offers a range of plastic stock shapes that are very suitable for laser marking. A few examples include TECAPEEK natural, TECAFORM AH LM white and TECASON P MT. POM is often difficult to laser, which is why TECAFORM AH LM white has been modified with a laser additive.

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