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Impact Dynamics of Porcine Drip Bloodstains on Fabrics

NCJ Number
251275
Author(s)
E. M. P. Williams, M. Dodds, M. C. Taylor, J. Y. Li, S. Michielsen
Date Published
May 2016
Length
7 pages
Annotation
Since the process of blood wicking into fabric complicates stain formation, this article describes the processes for passive drip stains collected under controlled conditions using anticoagulated porcine blood.
Abstract
As a passive blood drop impacts a hard surface, it is observed to collapse and spread laterally, then retract and settle. During the spreading phase, the edge of the drop may rise forming a crown extending into spines and breaking up into secondary drops. When a similar drop falls onto a textile surface these same processes may occur, but the process of blood wicking into the fabric complicates stain formation. In the current study, Three stages of this impact process were identified and could be separated into distinct time zones: (1) spreading (time t = 2.5 ms) and (2) retraction (2.5 = t = 12 ms) on the surface with potential splashing at the periphery, and (3) wicking (30 ms = t = 30 min) of the blood into the fabric. Although wetting and wicking may also occur for t < 30 ms, the vast majority of wetting and wicking occur after this time and thus the short-time wicking can be ignored. In addition, the number of satellite stains correlates with the surface roughness with the number of satellites for jersey knit > plain-woven > cardboard. Conversely, the size of the satellite stains correlates with the amount of wicking in the fabric with the satellite stain size for plain-woven > jersey knit > cardboard. (Publisher abstract modified)

Date Published: May 1, 2016