Perforation of Plastic Films with Carbon Dioxide Laser Radiation

摘要

Perforation of the plastic film which forms the walls of a salt pellet sub-pack was accomplished using the focused beam from a carbon dioxide laser operating at 10.6 microns wavelength in the TEMoo mode. Typical hole sizes were 6 to 12 mils in diameter with two holes punched simultaneously, one in each of two layers of plastic film separated by approximately 0.2 inch. The holes thus obtained were clear of obstructions and had smooth, rounded edges. Polyethylene was found to yield the best results. A double exposure of the packet to the radiation produced the most reliable and consistent operation. Typical values of exposure were 100 milliseconds and 67 milliseconds respectively at a power level of 1.4 to 1.6 watts. A short production run was executed to provide a quantity of perforated salt pellet sub-packs for statistical evaluation. In addition, design details of a production line machine to perforate packets at a nominal rate of one packet per second were developed. A brief study to determine the feasibility of sealing and cutting polyethylene film using carbon dioxide laser radiation was accomplished. The results of this study indicate that sealing and cutting are feasible. (Author)