• Phd

STUDY ON EFFICIENCY OF PULSE Nd:YAG LASER IN PAINT REMOVAL AND ITS HEALTH IMPLICATIONS

 

 

ABSTRACT

 

Laser paint removal is identified as an ideal technology to replace conventional chemical technique in motocar paint removal process in order to maintain sustainability of our environment and human life. However, information of this technology in automotive industry is less discussed, as well as their efficiency process and optimum of laser parameters is not well documented.

 

This research was done to identify the optimum operation of Cynosure Cynergy Pulse Nd:YAG laser in removing the paint layers onto selected national and imported cars substrate in Malaysia. The study focused to determine the average efficiency in paint stripping by using Nd:YAG laser and at the same time to investigate the health implications during the process.

 

The determination of normalization mass of particulate matter per one laser shot and 1.0 cm2 beam size as well as measurement of average of temperature changes during the laser irradiation were done onto 540 crater depths. Furthermore, the irradiated samples were proceed to surface texture and structure analysis, surface morphology analysis and elemental composition determination by using infinite focus metrology, field emission scanning electron microscopy and energy dispersive x-ray.

 

The study concludes the increasing of laser fluence energy was increased the efficiency of paint removal. However, the influence of repetition rate and pulse width of laser parameters were not significant in stripping process due to small range scale and long pulse mode characteristics. The research also concludes the laser paint removal techniques was considered safe compared than chemical paint stripping technique.

 

Optimum operational process for sample A was set-up with pulse width 100 ms, repetition rate 1.0 Hz and beam size 5 mm at fluence energy 180 J/cm2. For sample B, the optimum operational process was set-up at pulse width 200 ms, repetition rate 1.0 Hz, beam size 5 mm at fluence energy 220 J/cm2, whereas sample C was set-up with pulse width 100 ms, repetition rate 2.0 Hz, beam size 5 mm at fluence energy 150 J/cm2. Thus, the study proved the effectiveness, quality and efficiency of paint removal process can be obtained with the proper selection of parameters of Cynosure Cynergy Pulse Nd:YAG laser.

 

KAJIAN KECEKAPAN LASER Nd:YAG DENYUTAN DALAM PENANGGALAN CAT DAN IMPLIKASI KESIHATANNYA

ABSTRAK

 

Penanggalan cat menggunakan laser dikenalpasti sebagai satu teknologi yang ideal untuk menggantikan teknik kimia konvensional dalam proses penanggalan cat motokar untuk mengekalkan dan memulihara persekitaran dan kehidupan manusia. Walaubagaimanapun, informasi teknologi ini dalam industri automotif kurang dibincangkan, begitu juga proses kecekapan dan parameter optimum laser tidak dibukukan dengan baik.

 

Penyelidikan ini dilaksanakan untuk mengenalpasti operasi optimum laser Cynosure Cynergy Nd:YAG Denyutan dalam penangggalan lapisan cat ke atas substrat kereta nasional dan import di Malaysia. Kajian menfokuskan kepada penentuan purata kecekapan dalam penanggalan cat menggunakan laser Nd:YAG dan pada masa yang sama menyelidik implikasi kesihatan sepanjang proses ini.

 

Penentuan penormalan jisim unsur partikel kepada satu tembakan laser dan 1.0 cm2 keluasan alur sebagaimana penentuan purata perubahan suhu sepanjang iradiasi laser telah dilakukan ke atas 540 kedalaman kawah. Selanjutnya, sampel teradiasi ini diteruskan untuk analisis struktur dan tekstur permukaan, analisis morfologi permukaan dan penentuan komposisi unsur meggunakan metrologi fokus infiniti, mikroskopi pengimbas elektron pancaran medan dan penyerakan tenaga x-ray.

 

Kajian merumuskan peningkatan tenaga fluensi laser telah meningkatkan kecekapan penanggalan cat. Walaubagaimanapun, pengaruh kadar ulangan dan lebar denyutan parameter laser adalah tidak siknifikan dalam proses penanggalan disebabkan oleh julat skala yang kecil dan ciri – ciri mod denyutan panjang. Penyelidikan ini juga merumuskan teknik penanggalan cat menggunakan laser telah dipertimbangkan lebih selamat berbanding teknik penanggalan cat menggunakan bahan kimia.

 

Proses operasi optimum untuk sampel A telah diatur dengan lebar denyutan 100 ms, kadar ulangan 1.0 Hz dan saiz alur 5 mm pada tenaga fluensi 180 J/cm2. Untuk sampel B, proses operasi optimum telah diatur pada lebar denyutan 200 ms, kadar ulangan 1.0 Hz, saiz alur 5 mm pada tenaga fluensi 220 J/cm2, manakala sampel C telah diatur dengan lebar denyutan 100 ms, kadar ulangan 2.0 Hz, saiz alur 5 mm pada tenaga fluensi 150 J/cm2. Demikian, kajian ini membuktikan keberkesanan, kualiti dan kecekapan proses penanggalan cat boleh diperolehi dengan pemilihan parameter yang betul dari laser Cynosure Cynergy Nd:YAG Denyutan