Search

Highlights: [•] Single and multi-layer packaging films are subject to 0.5–12.5ns pulsed laser exposure. [•] Ablation thresholds, ablation depths and interaction and cut widths are obtained. [•] Pulse duration and number have the greatest effect on ablation of plastics. [•] Laser wavelength and pulse number have the greatest effect on ablation of metals. [•] Metallic layer thickness and heat flow dictate the response of multi-layer films. [ABSTRACT FROM AUTHOR]

AbstractSamples of two historical papers from the late 17th and early 18th centuries were irradiated with a 350-nm ?maxlight source. Atomic force microscopy examination of untreated samples of these laid paper sheets revealed notable surface inhomogeneity. Diffuse brightness values show that irradiation resulted in an initial decrease followed by a rapid increase in brightness with increasing irradiation time from 0.5 to 28 h. The bleaching effect then slowed, following a logarithmic path that did not plateau within 197 h of irradiation time. Irradiated sheets stored for 3 months exhibited brightness reversion of 7%. Fluorescence also decreased with irradiation time if excitation wavelengths of 320, 350, and 400 nm were applied for samples exposed to narrow-band irradiation at 350 nm. The fold endurance decreased by 34–72% after 197 h of irradiation. Changes in tear and tensile values were less dramatic. The Z-direction ultrasonic velocity decreased after 197 h of irradiation; however, the ultrasonic conductivity partially recovered during 9 months of storage. [ABSTRACT FROM AUTHOR]

The article contains experiment to demonstrate fluorescent emission spectra of neon colored papers and plastic clipboards. The findings indicate that the shorter wavelength light is utilized by the “Daylight" pigment contained in these neon papers to enhance the reflected light in the longer wavelength regions thus making them appear brighter.