Optical features of flax fibers coming from the Turin Shroud

Abstract

Abstract. This paper presents a study of flax fibers coming from the TS (Turin Shroud) and evidences their peculiar features if compared with recent ones. A further comparison between image-fibers and non-image-fibers shows both structural and chemical differences especially in correspondence of the external layer about 200 nm thick.The PLM (Polarized Light Microscopy) is used to evidence the various features of the TS fibers, and these features are then explained also at the light of the ancient procedure used to produce fibers from flax plants.Optical microscope and SEM (Scanning Electron Microscope) are used to better show the various fiber's features evidencing the presence of impurities and defects.Finally an opto-chemical analysis is performed showing results of TS fibers relative to CIELAB values, FT-IR ATR and Raman tests also trying to interpret, from a chemical point of view, some peaks present in the spectra.

Statistical and Proactive Analysis of an Inter-Laboratory Comparison: The Radiocarbon Dating of the Shroud of Turin

“…More recent SEM analyses of Shroud fibers in [ 45 ] confirmed the abundant deposits of pollutants reported in [ 44 ].…”

X-ray Dating of a Turin Shroud’s Linen Sample

“…To verify this eventuality, we measured the WAXS maps of linen samples before and after exposure to a temperature of 200 • C in an oven for half an hour, without any control of the relative humidity, which became very low during the fabric's exposure at these temperatures, as happens in real accidental fires. After this thermal treatment, the WAXS map of the samples was unaltered, as shown by the integrated profiles reported in Figure 4, but the yellowing of the linen was very pronounced, as was also seen in the experiments discussed in [20], where a detailed study about the linen yellowing, as a function of both the oven temperature and the time permanence in the oven, was performed. mal treatment, the WAXS map of the samples was unaltered, as shown by the integrated profiles reported in Figure 4, but the yellowing of the linen was very pronounced, as was also seen in the experiments discussed in [20], where a detailed study about the linen yellowing, as a function of both the oven temperature and the time permanence in the oven, was performed.…”

“…After this thermal treatment, the WAXS map of the samples was unaltered, as shown by the integrated profiles reported in Figure 4, but the yellowing of the linen was very pronounced, as was also seen in the experiments discussed in [20], where a detailed study about the linen yellowing, as a function of both the oven temperature and the time permanence in the oven, was performed. mal treatment, the WAXS map of the samples was unaltered, as shown by the integrated profiles reported in Figure 4, but the yellowing of the linen was very pronounced, as was also seen in the experiments discussed in [20], where a detailed study about the linen yellowing, as a function of both the oven temperature and the time permanence in the oven, was performed. The reason that a thermal shock at 200 °C does not affect the natural aging level of cellulose is related to the fact that, during a fire, the relative humidity becomes very low, reducing the reaction rate 𝑘 of the linen DP degradation by at least one order of magnitude.…”

Polarimetric inspection of flax composite material reinforcements

“…Despite a few works, 1, 10, 11 polarimetric imaging is not very popular in the field of textile or fiber science, except at a microscopic level: 12 polarizing properties of textile materials (especially birefringence), whether for natural or artificial fibers, have been mentioned since the 1940s (please read 13 for a review). As mentioned earlier, in most cases, at a macroscopic level, textile surfaces exhibit diffuse reflection in which polarimetric signals are weak.…”