AIR CONTAMINANTS GENERATED DURING LASER PROCESSING OF ORGANIC MATERIALS AND PROTECTIVE MEASURES

As compared to other thermal processes, during laser material. process ing of organic materials gaseous and particulate emissions are generat ed. Characteristic for laser-generated air contaminants (LGACs) are th e large number of components, the chemical complexity, and the varying emission rates. The characteristics and hazards of these LGACs must b e well known, in order to take adequate protection measures to ensure a safe laser workplace and to achieve a high environmental compatibili ty. Within research projects and the framework of the European project Eurolaser: EU 643 ''Safety in the industrial applications of lasers,' ' emissions have been characterized and medically assessed. Studies sh ow that the quantity, the composition, and the chemical complexity of the LGACs are highly dependent on the laser application, the process p arameters and the material processed. Generally, the particles generat ed are very small and therefore can be mainly respirated. For some pla stics, like polyamides, the fume particles are viscous and can easily stick together. The gaseous hydrocarbon emissions usually consist of s ubstances referring to the chemical structure of the material machined , often, the monomers. Aromatic hydrocarbons and polycyclic aromatic h ydrocarbons are detected in all cases. Investigations on filter system s show that nonadhesive particles can be filtered efficiently with sel f-cleaning surface filters; sticky particles, however, cause high pres sure loss in the filter and the capture efficiency will rapidly drop. For organic gaseous emissions, no standard filter solution is availabl e. In general, adsorption techniques, catalytic combustion, or biologi cal filtration can be used. (C) 1998 Laser Institute of America.