Clariant, partners develop laser marking process of flexible packaging

Swiss chemicals company Clariant AG has teamed up with pigment supplier Merck KGaA and polymer producer Sabic to develop laser-marking technology and materials to ease the recycling process for flexible polyethylene (LDPE, LLDPE) packaging film. 
 
For the partnership, Sabic will be supplying a range of polymers for packaging, including its “certified circular polymers”, which use Tacoil feedstock, an oil produced through the chemical recycling of low quality, mixed plastic waste.
 
Laser-sensitive Iriotec pigments and marking expertise are provided by Merck, while Clariant will contribute its additive masterbatch formulations developed for use in the film extrusion process.
 
“There is growing demand for clean, high-quality recycled PE,” said Chun-Yip Pang, Clariant’s global product manager additive masterbatches, adding that despite the increasing rate of recycling for PE films, there still remain a number of challenges.
 
“This collaboration is focused on eliminating the printing ink used for tracking, shelf-life, bar codes and other variable information that must be placed on almost any package on the market. Less ink means less contamination when it comes to recycling,” he explained.
 
The challenge with laser marking plastics is that the material is transparent to the radiation used in the laser-marking process.
 
This is where Clariant’s additives are necessary to achieve a visible reaction in the film.
 
The marks are permanent and resistant to water, oil, grease or fatty foods, Clariant said in a 25 Sept release.
 
The technology can be applied to the surface of mono-layer film, or a laser-sensitive layer can be placed behind a laser-transparent surface layer. The additives provide high contrast and allow high-speed marking.
 
At K 2019, to be held 16-23 Oct in Düsseldorf, the partners will show several examples of laser-marked packaging films and pouches.