Laser marking system for plastic products

Abstract

This research paper solves the challenge of plastic product marking. In particular, plastic cap marking. Nowadays, IR lasers (fiber, solid-state, gas lasers) are used for plastic marking, in most cases these are 1.06 µm fiber lasers, but plastics must contain metal additives for obtaining a high-quality marking with such a laser. And those additives are not safe for plastic products in the food industry. This problem is solved by using high-energy UV lasers. Therefore, the NII Laser Technology PJSC team has developed and produced a comprehensive system for high-resolution marking of both plastic products and other materials (metal, glass, ceramics) based on an ultraviolet laser. A combination of 2D-scanning technology, adaptive focusing, marking of objects in motion (on-the-fly), as well as a number of other technological and design solutions in this system made it possible to start production of conveyor lines for dynamic marking of beverage closures, crown caps, elongated plastic and metal caps amongst others that are used in the food industry. In comparison to the existing marking technologies, the developed laser marking comprehensive system provides high-speed (up to 100 thousand caps per hour) marking with text, digital and graphic data on the outer surfaces of the plastic produced without any special coloring agents, and allows getting a contrast image by using gray shading regardless of the surface color. At the present day, NII Laser Technology PJSC has carried out work to expand the capabilities of the laser marking comprehensive systems through the introduction of 3D scanning technology and the use of two band laser systems, that increase the product protection. The safety of using ultraviolet radiation for marking the internal surfaces of food packaging plastic elements is confirmed by the certificate on laboratory testing by INSTITUT NEHRING GmbH - Heesfeld 17-38,112 Braunschweig