Технологія і техніка друкарства (Dec 2017)
Analysis of the Causes of Rejection of Banknote Production
Abstract
The main types of defects in banknote products that led to its rejection were analyzed. The percentage of these defects was determined. It was found that the biggest shortage is caused at the stages of offset printing and intaglio printing (17,4 % and 21,1 % respectively). The analysis of the types of defects, which appeared during offset printing process, showed that the most frequent defects are image non-printing and the insufficient saturation of the parts of the imprint (23,3 %), the deviation of the color of the print from the approved color of the note (21,4 %), the mismatch of the line thickness (17,3 %), non-printing on the watermarks (9,7 %). The range of reasons of defects is wide: from the selection of materials to the contamination of the printing machine. Non-printing and insufficient saturation of the parts of the imprint can be caused by the supply of insufficient amount of printing ink to the ink system and to the printing form, the weak pressure between the printing and offset cylinders, the emulsion of the printing ink (for the offset printing method with moisture); the color deviation of the imprint may cause discrepancies in the color characteristics of the printing ink or the paper; the shadow of the printing ink can be caused by defects in the printing form, excessive supply of printing ink or its insufficient viscosity, insufficient amount of moisture solution (for offset printing method with moisture); non-printing on a watermark may be caused by heterogeneity of paper and unregulated of printing ink transfer and pressure between printing and offset cylinders. On the basis of the generalization of these data, a classification of major defects in banknote products was created. This will be the basis for identifying areas for improving the manufacturing process and, consequently, improving the quality of banknote products.
Keywords
