With a water, particulate and fibre mixture, a method of quantifying fibre content may include providing a sample of the mixture, filtering the sample to produce a particulate and fibre mixture, burning the particulate and fibre mixture to produce a fibre sample, and dissolving the fibre sample to produce a fibre solution. The fibre solution may be analyzed to determine an elemental content of the fibre solution. The elemental content may be compared to a known elemental content to estimate the fibre content.

Methods of characterizing the topography of a surface of a creped material, devices for characterizing surface topography of a creped material, computer systems for characterizing surface topography of a creped material, and the like, are disclosed.

The invention relates to a method and arrangement for detecting free fiber ends in a paper surface. The method comprises illuminating a target sample (6) surface, which comprises free fiber ends, from at least two directions one at the time, with at least one light source (1). Original reflectance images are obtained for the target sample (6) surface with an imaging device (4), and a surface normal is estimated for each image pixel of the original reflectance image. Thus it is possible to reconstruct a reconstructed reflectance image from the estimated surface normals, and to compare the reconstructed reflectance image and the corresponding original reflectance image and to construct a difference image, where the differences represent shadow objects of the free fiber ends in a paper surface.

A method includes, using at least one processing device, obtaining position measurements and/or tilt angle measurements associated with a tissue web and identifying a stretch measurement associated with the tissue web using the obtained measurements. Identifying the stretch measurement could include using one or more mathematical formulas to calculate the stretch measurement associated with the tissue web using the obtained measurements. The one or more mathematical formulas could be defined using laboratory stretch values of multiple training webs. Different mathematical formulas can be associated with training webs having different characteristics, and the method may further include selecting at least one of the mathematical formulas based on one or more characteristics of the tissue web.

The present invention relates to determination of the microorganism content in material comprising cellulose within the pulp and paper industry. The material comprising cellulose is enzymatically pretreated and microorganisms are determined using PCR based technology.

The present invention relates to determination of the microorganism content in material comprising cellulose within the pulp and paper industry. The material comprising cellulose is enzymatically pretreated and microorganisms are determined using PCR based technology.

An apparatus adapted to examine a paper web includes a rotatable first bobbin, a rotatable second bobbin, and a first testing device. The first bobbin has a paper we wound thereabout that has transverse bands spaced apart along a length thereof. The second bobbin is arranged to receive the paper web from the first bobbin with a paper web path defined between the first and second bobbins. The first testing device is disposed along the paper web path and is arranged to nondestructively measure a diffusivity of one of the transverse bands of the paper web.

An apparatus adapted to examine a paper web includes a rotatable first bobbin, a rotatable second bobbin, and a first testing device. The first bobbin has a paper we wound thereabout that has transverse bands spaced apart along a length thereof. The second bobbin is arranged to receive the paper web from the first bobbin with a paper web path defined between the first and second bobbins. The first testing device is disposed along the paper web path and is arranged to nondestructively measure a diffusivity of one of the transverse bands of the paper web.

A sample of an aqueous stream is conducted to an optical measurement device. A hydrophobic dye is added. The sample is fractionated into fractions according to particle size or mass. The fluorescence intensity values and light scattering intensity values for the fractions are measured. The fluorescence intensity values of the fractions are added together thus obtaining a sum of the fluorescence intensity values. The light scattering intensity values of the fractions are added together, thus obtaining a sum of the light scattering intensity values. A hydrophobicity density of the particles in the sample, is calculated by dividing the sum of the fluorescence intensity values with the sum of the light scattering intensity values, and the concentration of hydrophobic contaminants in the aqueous stream is monitored and controlled based on the calculated hydrophobicity density of the particles in the sample.

Herein provided are methods for evaluating cellulose nanofiber dispersions, comprising the steps of: (1) preparing a cellulose nanofiber dispersion; (2) adding a color material into the cellulose nanofiber dispersion; and (3) observing the cellulose nanofiber dispersion to which a colored pigment has been added with a light microscope. The methods allow for easy evaluation of whether or not agglomerates of cellulose nanofibers exist in cellulose nanofiber dispersions, which cannot be visually determined.