Research On Hand-held Laser Cleaning System

In the current industrial production,the traditional cleaning methods are mainly physical cleaning ? chemical cleaning ? electronic cleaning ? ultrasonic cleaning,etc.These traditional cleaning methods can only be used to remove surface particles,which not only has the poor cleaning effect and the low cleaning efficiency,but also easily pollute the environment.With the improvement of people's awareness of environmental protection and the pursuit of higher cleaning efficiency in the industry,it is a key issue that we are looking for to find a cleaner,more efficient and non-damaging cleaning method.Laser cleaning is a technology of focusing the laser beam through an optical system to obtain a high-energy laser beam,irradiating to the surface of the material that to be cleaned,and removing the surface attachments by the heat of the interaction between the laser and the material that to be cleaned.It is a new type of cleaning technology which is gradually emerging in recent years.Laser cleaning technology has attracted extensive attention because of its incomparable advantages to the traditional cleaning technology.Laser cleaning equipment has just started in our country,mature laser cleaning equipment especially hand-held laser cleaning equipment has a huge demand.This paper studied the laser cleaning theory and laser cleaning process,and designed a practical hand-held cleaning equipment.The main contents and results of this paper are as follows:(1)Through finite element numerical simulation method,the temperature distribution,stress distribution and displacement of the substrate,paint layer and rust layer were calculated during the cleaning process when the flat-top laser and the Gaussian laser were applied to the paint and corrosion layer of iron substrate,the feasibility of laser cleaning with pulsed fiber laser was verified theoretically.(2)The effects of scanning speed and laser repetition frequency on laser cleaning were studied.The results show that the scanning speed and laser repetition frequency have a significant effect on the laser cleaning effect: slow scan speed,the laser pulse accumulation is higher,can effectively remove the po llution layer,but may produce secondary oxidation phenomenon,the higher scanning speed may not be able to remove stubborn pollution layer;The laser pulse frequency affects the laser power density,the large pulse laser energy density can effectively remove the contamination layer on the surface of the sample,but because the substrate temperature is too high,the substrate is oxidation.The small pulse laser energy density can not effectively remove the stubborn contamination layer on the surface of the sample.Actually,it is considered for laser cleaning that the appropriate process parameters has to be optimally choosed for the actual situation of pollutants.(3)Finally,we designed a hand-held laser cleaning system,which consists of pulsed fiber laser,laser fiber,optical fiber collimating output isolator,scanning galvanometer,field lens and the control system.The practical test of the laser cleaning system is also carried out.The test results show that our laser cleaning system has a good cleaning effect.The whole system is simple in structure,flexible in operation and good in generality.