Determination of paper filler Z‐distribution by low‐vacuum SEM and EDX

Abstract

SummaryPaper, mainly constituted of cellulose fibres, often contains mineral fillers. These fillers increase some of the properties of the paper (whiteness, printability, etc.) and are cheaper than the cellulose fibres. Nevertheless, the fillers reduce the mechanical properties of the sheet. Paper presents an anisotropy corresponding to three main directions. This anisotropy characterises the sheet mechanical properties, structure and filler distribution. Analyses of the cross section of the paper sheet with a low-vacuum scanning electron microscope with an energy dispersive spectrometer analysis module can show this distribution. The procedure developed consists in analysing discrete profiles to build the mean profile known as filler Z-distribution for each of the fillers. To develop this method, problems such as determination of the surface points, the number of points to analyse to define a cross section profile and the time required for the test, have been solved. Paper is sensitive to electron irradiation. In order to avoid deterioration of the material and to obtain satisfactory results, the time span for analyses is restricted to 40 s with a 12 kV electron beam accelerating voltage. Monte Carlo simulations are used to determine the diffusion cloud size and thus to determine the number of points that constitute a profile. The samples are gold sputtered and, with the aid of backscattered imaging, the coated surface allows determination of the sample surface points.

Materials properties of paper as influenced by its fibrous architecture

“…[157][158][159] Accordingly, there has been recent interest in improving analysis of this aspect of sheet structure. Microscopical techniques now provide quantitative analysis of the distribution of filler particles including partitioning of this component of the structure into individual mineral types [160][161][162] and X-ray microtomography is providing robust quantification of density and filler distribution in the thickness direction. 28,163 In our earlier discussion of the porous structure of paper, we noted that microtomographic measurements show that pore dimensions perpendicular to the plane of the sheet are smaller than the in-plane dimensions.…”

Biodegradation of ivory (natural apatite): possible involvement of fungal activity in biodeterioration of theLewisChessmen

“…Reference elemental intensities acquired from pure compounds (standards) are commonly utilized for calibrating SEM–EDS systems. In this work, conventional ZAF correction (correction for Z, atomic, A, absorption and F, fluorescence) (Roux et al ., ) integrated into the Oxford INCA 250 microanalysis package was applied to the spectrum data set (Oxford Instrument, UK). After observing samples with the SEM in variable pressure mode at 20 keV, some of the samples were covered with gold using a Baltec Sputter Coater for further examination in high vacuum mode.…”

Analysis of fibres using microscopy

“…For imaging fibre composites, SEM can also identify inorganic phases in the composite by using atomic number contrast, a characteristic of backscattered electrons (Fig. 4.5) (Rothbard 2002;Roux et al 2008). X-ray analysis by energy dispersive spectroscopy (EDS) can also determine the elemental composition of fibres and composites (Roux et al 2008;Goldstein et al 2003).…”