Journal article

Publication year: 2008

Pages: 23-31

Journal: Forensic Science International

Volume number: 180

Issue number: 1

ISSN: 0379-0738

Open access status: Green

DOI Link: https://doi.org/10.1016/j.forsciint.2008.06.012

Publisher: Elsevier

Abstract: 
Artificial aging has been used to reproduce natural aging processes in an accelerated pace. Questioned documents were exposed to light or high temperature in a well-defined manner in order to simulate an increased age. This may be used to Study the aging processes or to date documents by reproducing their aging curve. Ink was studied especially because it is deposited on the paper when a document, such as a contract, is produced. Once on the paper, aging processes start through degradation of dyes, solvents drying and resins polymerisation. Modelling of dye's and solvent's aging was attempted. These processes, however, follow complex pathways, influenced by many factors which can be classified as three major groups: ink composition, paper type and storage conditions. The influence of these factors is such that different aging states can be obtained for an identical point in time. Storage conditions in particular are difficult to simulate, as they are dependent on environmental conditions (e.g. intensity and dose of light, temperature, air flow, humidity) and cannot be controlled in the natural aging of questioned documents. The problem therefore lies more in the variety of different conditions a questioned document might be exposed to during its natural aging, rather than in the simulation of such conditions in the laboratory.Nevertheless, a precise modelling of natural aging curves based on artificial aging curves is obtained when performed on the same paper and ink. A standard model for aging processes of ink on paper is therefore presented that is based on a fit of aging curves to a power law of solvent concentrations as a function of time. A mathematical transformation of artificial aging curves into modelled natural aging curves results in excellent overlap with data from real natural aging processes.

Harvard Citation style: Weyermann, C. and Spengler, B. (2008) The potential of artificial aging for modelling of natural aging processes of ballpoint ink, Forensic Science International, 180(1), pp. 23-31. https://doi.org/10.1016/j.forsciint.2008.06.012

APA Citation style: Weyermann, C., & Spengler, B. (2008). The potential of artificial aging for modelling of natural aging processes of ballpoint ink. Forensic Science International. 180(1), 23-31. https://doi.org/10.1016/j.forsciint.2008.06.012