Primary Emission And Secondary Generation Of PM_2.5 And Chemical Components During And After Printing

Use the experiment box to carry out the research on the primary emission and secondary generation of PM_2.5 under the printing working conditions.Simultaneously collect PM_2.5 in the experiment box and analyze and determine chemical components such as organic carbon,elemental carbon,inorganic ions and organic acid radicals.Quantify the primary emission rate of PM_2.5 under printing working conditions,and explore the PM_2.5 particle size distribution in different stages.Based on the characteristics of PM_2.5 components,the impact of printing on the secondary generation of PM_2.5 is analyzed.The main conclusions are as follows:（1）Printing will increase the concentration of indoor PM_2.5.The number density emission rate of PM_2.5 in the printing stage of HP104W and HP1008 printers under different printer working conditions are 3.28～65.77×10⁷ and 18.01～241.11×10⁷piece/min.In the PM_2.5 filter collection experiment,the average mass concentration emission rates of PM_2.5 in the printing stage of HP104W and HP1008 printers were102.80 and 19.50μg/h.（2）Different models of printers or the same model of printers under different printing working conditions,at the printing stage or the 0～1 h stage after printing,the particle size distribution characteristics of the PM_2.5 number concentration in the experiment box are different.Under different printer working conditions,the average particle size of the particles in the box after printing is smaller than the average particle size of the particles in the box at the printing stage,but greater than the average particle size of the particles in the box before printing.（3）Different models of printers or the same model of printers under different printing conditions,the time period during which the PM_2.5 number concentration particle size distribution characteristics of the experimental box changes after printing is different.（4）The dominant components of carbon components in the PM_2.5 emitted by the two models of printers during the printing stage are OC₁,OC₂,OC₃,and the dominant components of the 13 water-soluble ions measured are Na⁺,SO₄^2-,Cl^-and Ca²⁺.The proportion of PM_2.5 emitted by different models of printers is different,which is related to the operating conditions of the printer（the temperature required to melt the toner,the laser beam emitted by the printer,etc.）.（5）Based on the comparison of the component characteristics of PM_2.5 in the printing stage and after the printing of the two models of printers,it is found that there is a secondary generation of PM_2.5 after the printing of the HP1008 and HP104W printers.