Multiple pulse heating cycles during the enclosed laser ablation of a laminated metallized polymer

Abstract

A vacuum-deposited aluminium layer (about 20nm) is sandwiched between two layers of laminated oriented polyporpylene (OPP) film whose thickness varies from 20 to 40 μm. Selected areas of this sealed system were transparentised by the rearrangement of the aluminium layer without breaking the seal or causing damage to the OPP film using a 75 W Q-swiched neodymumdoped yttrium aluminium garnet laser. This paper investigates the effecst of the laser repetition with changes in experimentally produced laser tracks.

Laser stripping of TiAlN coating to facilitate reuse of cutting tools

“…To overcome the problems with existing stripping processes, the feasibility of using a laser ablation process to remove TiAlN coating without any damage to the substrate was explored in this study. The laserstripping process can be programmed to remove coatings on selected areas, operate under remote control and be automated [10][11][12][13][14]. Furthermore, it is a coolant and chemical hazard free process.…”

Rapid vaporization mechanism in enclosed laser ablation

“…As significant as the maximum temperature reached during laser heating is the form in which the overall cooling of the films take. Previous work [7] shows that the maximum temperature reached by the inner polymer surfaces which are in contact with the aluminium is approximately 45% of that of the maximum aluminium temperature and will take 10 −7 s −1 to be reached. This paper also shows that the temperature of the polymer films are raised by between 10˚C and 20˚C for each pulse which generates a temperature of 1000˚C on the aluminium surface.…”

“…With further reasoning, it can be seen that the greater the temperature reached by the aluminium film, the greater the temperature of the polymer surfaces surrounding it and the subsequent total temperature rise of the film. OPP degrades within the temperature range of 400-600˚C [7]. In the absence of oxygen, polypropylene will degrade to smaller, gaseous hydrocarbons.…”

Enclosed laser ablation of aluminium films using a continuous wave diode laser: II—Theoretical heating considerations and proposed mechanisms

“…The heated area can cool by both conduction through the surrounding areas of the aluminium layer or through conduction into the top and bottom layers of the polymer. Previous work has shown that, due to the thinness of the aluminium layer (20 nm), cooling through the aluminium accounts for only a small percentage (¿ 8%) of total cooling and therefore can be disregarded [4].…”