Effect Of Ink Key Presetting On Printing Quality And Compensation For Magnum 4? Offset Printer

During the pre-printing preparation in a web offset printer,it's important to reduce the amount of waste copies as much as possible,because it both saves time and cost.One of the methods to improve ready work efficiency is to preset the ink keys of the process before printing work starts.With introduction of Goss Magnum4II offset printing,detailed research on all printing cylinders layout and functions has been done.Furthermore,it has been focusing on aspects of ink control principle and its auto setting,close-loop control,self-adaption compensation.Printing dot,temperature and printing material also influence the printing quality.Analysis from format of 1-bit tiff,its features and read process,to necessity of printing area distribution,common rules and requirements and relation between print coverage rate and ink opening have been conducted.Ink key presetting mathematical model and ink transfer curve have been set up.Coverage rate and ink opening function via curve interpolation and fitting are created,and analyze the result of ink transfer curves.Solution to print dot expansion has been given.Finally getting others impact factors on ink transfer curve involved,like ink transfer rate,ink thickness,ink thixotropism and printing machine status etc.Ink key presetting programming work is done in MATLAB software environment.The relation between coverage rate and ink key opening and printing quality improvement is based on theoretical study result of this article.