QUALIFICATION OF PERSONAL PROTECTIVE EQUIPMENT FOR THE USE OF HAND-HELD LASER PROCESSING DEVICES

摘要

The number of applications for hand-held laser processing devices is increasing steadily. Starting with precision welding, today, hand-held laser processing devices are available for welding, cutting, cladding, hardening and cleaning. The devices are used in the automotive, engineering and tool making industry, and are currently tested in the shipbuilding industry. The safety of hand-held laser processing devices (HLDs) is a fundamental requirement. However, a number of questions regarding both the safe design and the safe use of the devices are still open. In 2005, a research project was started to test and qualify personal protective clothing for the use with handheld laser processing devices, and to define minimum safety requirements for laser protection. In a first step, a number of different commercially available technical textiles and leather that are used as heat and flame protection textiles (for e.g. welders, workers exposed to heat/flames and racing car drivers) were tested. Also, typical work clothing and leisure wear (cotton) were examined for comparison. The investigations cover various test methods and criteria to evaluate the behavior of the protective system, such as the transmittance of laser radiation, flammability, hole formation and subsequent beam penetration, and heat transfer to the skin. For the assessment of skin hazards the results are compared with MPE (IEC 60825-1) and the Stoll/Chianta criterion for a second degree burn (blister).