Enhancement of low power CO2 laser cutting process for injection molded polycarbonate

• Published in: Optics and laser technology Vol. 96; pp. 208 - 218
• Main Authors: Moradi, Mahmoud, Mehrabi, Omid, Azdast, Taher, Benyounis, Khaled Y.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2017; Elsevier BV
• Subjects: Carbon dioxide; Carbon dioxide lasers; Chemical compounds; Cutting parameters; Cutting speed; Design of experiments; Focal plane; Heat affected zone; Injection molding; Kerf; Laser beam cutting; Laser cutting; Lasers; Machine tools; Modeling and optimization; Process parameters; Statistical investigation; Surface roughness; Laser cutting; Injection molding; Statistical investigation; Design of experiments; Modeling and optimization
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2017.05.022

•CO2 laser cutting of polycarbonate injected sheets is investigated by DOE approach.•Parameters varied for DOE analysis are laser power, focal plane position, cutting speed.•Kerf geometry features and surface roughness of the kerf wall are output responses.•Locating the laser spot point in the depth of the workpiece leads to increases the laser cutting quality. Laser cutting technology is a non-contact process that typically is used for industrial manufacturing applications. Laser cut quality is strongly influenced by the cutting processing parameters. In this research, CO2 laser cutting specifications have been investigated by using design of experiments (DOE) with considering laser cutting speed, laser power and focal plane position as process input parameters and kerf geometry dimensions (i.e. top and bottom kerf width, ratio of the upper kerf to lower kerf, upper heat affected zone (HAZ)) and surface roughness of the kerf wall as process output responses. A 60 Watts CO2 laser cutting machine is used for cutting the injection molded samples of polycarbonate sheet with the thickness of 3.2mm. Results reveal that by decreasing the laser focal plane position and laser power, the bottom kerf width will be decreased. Also the bottom kerf width decreases by increasing the cutting speed. As a general result, locating the laser spot point in the depth of the workpiece the laser cutting quality increases. Minimum value of the responses (top kerf, heat affected zone, ratio of the upper kerf to lower kerf, and surface roughness) are considered as optimization criteria. Validating the theoretical results using the experimental tests is carried out in order to analyze the results obtained via software.