สำนักราชบัณฑิตยสภา

วารสารราชบัณฑิตยสถาน ปีที่ ๓๗ ฉบับที่ ๑ ม.ค.-มี.ค. ๒๕๕๕ Warinpong Jittiwattanapong 1 , Sukit Waranukulsak 1 , Boonchoat Paosawayanyong 2, 3, Suda Kiatkamjornwong, 1,4* 1 Department of Imaging and Printing Technology, Faculty of Science, Chulalongkorn University, Bang- kok 10330, Thailand; 2 Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. 3 ThEp Center, Commission of Higher Education, Bangkok, Thailand. 4 The Royal Institute Of Thailand, Bangkok 10300, *E-mail: ksuda@chula.ac.th Introduction Presently, utilization of petroleum-based plastic products increases continuously worldwide at approximately 200 billion tons per annual which is equivalent to an average consumption of 80-100 Kg per capita per year [1]. To compare with the leading countries, like the Americans, their recycle is just 7 percent of 48 billion tons of plastics annually. The recycling of the plastic products is only at 30% in Thailand. Thailand’s plastic consumption is increasing steadily to make the plastic waste accumulation up to 2 million tons per year. This amount of plastic waste has threatening the well being of Thai people and destroying the environment and ecological sustainability. Printing Properties of Water-based Pigmented Inkjet Inks on the Oxygen-plasma Modiffi ied Polylactide Sheets Abstract Oxygen plasma pretreatment on pure polylactide (PLA) sheet and associate printing properties by a set of water-based inkjet ink was investigated. Surface property of the sheet was controlled by power and exposure time of the plasma. Contact angle mea- surement was employed to observe wetting and calculate the total surface free energy. Surface morphology and surface roughness were observed by atomic force microscopy. Tone reproduction of the sheets printed with the inks indicated that the oxygen plasma treatment is capable of improving wettability, increased surface roughness, and color sharpness. The longer exposure time of the sheets improved more color qualities than did the irradiation power of the plasma and the optimum surface roughness produced the better printed color quality. Key words: Polylactide sheet, Oxygen plasma, Water-based inkjet ink, Color qualities