Omnistab NIR LW

The right laser absorber for plastic laser welding

Plastic laser welding is a new plastic processing technology. It originated in 1970 with carbon dioxide laser welding plastic film, when lasers were first demonstrated as being suitable for welding plastics. But because the carbon dioxide laser is very cumbersome and the transmission performance is poor, the operation is very inconvenient. And as the diode laser and semiconductor laser became more popular, the carbon dioxide laser gradually withdraws from the field of plastic welding.

The right laser absorber

The diode laser has a wavelength of 800 ~ 1000nm and the semiconductor laser has a wavelength of 1064nm, both in the near infrared range. In this wavelength range of the near-infrared, most plastics are transparent and both lasers can penetrate the plastic very easily. This means that finding a suitable laser absorber is important to further develop plastic laser welding technology.

This absorber must meet the following conditions:

  1. Strong absorption of 800 ~ 1064nm infrared light;
  2. Very stable under heat of at least 300 ℃;
  3. Good dispersion, compatible with polymer materials;
  4. High visible light transmittance that can be used with different pigments.

Partners in Chemicals’ R&D center in Israel’s  developed a new type of laser welding agent: Omnistab NIR LW. This product meets the above requirements for a laser absorber extremely well:

  1. The product can absorb 850 ~ 1250nm near infrared light, covering most of the diode laser range. The maximum absorption wavelength of the product is at 1050nm, very close to 1064nm for the semiconductor laser. This makes Omnistab NIR LW particularly suitable for diode laser and semiconductor laser.
  2. The product is stable under heat and can resist more than 350 ℃ high temperature, which is higher than the softening point of most polymer materials.
  3. The product is compatible with polymer materials. As far as we know, all polymers are compatible with Omnistab NIR LW.
  4. The color of the product is shallow. It’s very slightly green, and can be mixed with almost all the colors to adapt to a variety of customer requirements.

Through our customer experiment Omnistab NIR LW obtained a satisfying result. No matter the PC or the PMMA, the welding strength are more than the strength of the material itself, while the color of the weldment is also very light.