Groundwork for Non Intentionally Added Photoinitiator Identification in Polyolefin Streams
Groundwork for identifying non-intentionally added photoinitiators in polyolefins requires high-resolution mass spectrometry and toxicological screening.
UV Curable Inks
Meaning
Polymeric coating formulations that undergo rapid polymerization when exposed to ultraviolet radiation to form a durable print on plastic substrates. It governs the speed of the printing line and stops applying once the ink layer has reached its final hardness and chemical resistance.
Instant Curing
High intensity light triggers a photoinitiator to start a chain reaction that solidifies the liquid film in seconds. Because uv curable inks do not rely on solvent evaporation, the process emits fewer volatile organic compounds than traditional printing. This speed allows for immediate handling and stacking of moulded parts.
The rapid transition from liquid to solid prevents the ink from bleeding into the polymer grain.
Adhesion Property
Chemical bonds form between the ink and the polymer surface to ensure the print survives mechanical stress or moisture. Proper surface treatment like corona or flame application often precedes the printing stage to improve wetting. If the surface energy is too low, the ink will delaminate during use.
Adhesion is tested using a standard tape pull method.
Removal Difficulty
Crosslinked structures created during the cure make these inks difficult to separate from the base resin during mechanical recycling. Many standard washing processes cannot strip the coating, leading to discoloured or contaminated recyclate. Solvent deinking or advanced filtration is required to produce high quality clear flakes.