According to an example aspect of the present invention, there is provided a method, comprising: controlling suction with predetermined force in a known measurement area to a moving cardboard or paper web in a manufacturing process, detecting on-line measurement information on deviation of the moving cardboard or paper web in the manufacturing process caused by the suction with predetermined force in the known measurement area, and determining elastic modulus of the moving cardboard or paper web in the manufacturing process on the basis of the measured deviation.

The present invention relates to a measurement system for use in a corrugating machine and a corrugating machine and a method of checking the process for producing paper adhesions with such a measurement system. The measurement system according to the invention for use in a corrugating machine comprises a measurement device. The measurement device can detect electromagnetic waves in the infrared range here and is aimed at a region of a transportation device of the corrugating machine in the direction of transportation downstream of an adhesion station of the corrugating machine.

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 measurement apparatus of a moving paper web, includes an optical radiation source that outputs optical radiation toward a scattering element of the measurement apparatus. The scattering element scatters the optical radiation, and a transmitting surface of the scattering element directs the optical radiation in a scattered manner toward the moving paper web. A distance between said transmitting surface of the scattering element and a surface of the paper web is known, and the transmitting surface and a detector of the apparatus are on opposite sides of the paper web. The detector receives at least a part of the optical radiation, which is side-scattered from the moving paper web. The detector determines a moisture value and a dry weight of the paper web on the basis of spectral information on the received optical radiation and the known distance.

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.

To provide tissue paper excellent in softness and smoothness. In tissue paper that is two-ply non-moisturizing tissue paper to which no chemical solution is applied, a basis weight per sheet is 10.0 to 18.0 g/m.sup.2, the thickness of two plies is 100 to 240 μm, a dry tensile strength in the paper horizontal direction is 70 to 180 cN/25 mm, a wet tensile strength in the paper horizontal direction is 25 to 55 cN/25 mm, and a free sensory evaluation value E.sub.f calculated according to the following Equation 1 is 3.7 to 6.6, and a slip sensory evaluation value E.sub.s calculated according to the following Equation 2 is 5.0 to 8.2.

Free sensory evaluation value E.sub.f=−2.879×(dry tensile strength in paper horizontal direction)+6.55×(wet tensile strength in paper horizontal direction)+5.36  (Equation 1)

Slip sensory evaluation value E.sub.s=−8.80×(dynamic friction coefficient)−0.41×(arithmetic mean surface roughness)+13.58  (Equation 2)

To provide tissue paper excellent in softness and smoothness. In tissue paper that is two-ply non-moisturizing tissue paper to which no chemical solution is applied, a basis weight per sheet is 10.0 to 18.0 g/m.sup.2, the thickness of two plies is 100 to 240 μm, a dry tensile strength in the paper horizontal direction is 70 to 180 cN/25 mm, a wet tensile strength in the paper horizontal direction is 25 to 55 cN/25 mm, and a free sensory evaluation value E.sub.f calculated according to the following Equation 1 is 3.7 to 6.6, and a slip sensory evaluation value E.sub.s calculated according to the following Equation 2 is 5.0 to 8.2.

Free sensory evaluation value E.sub.f=−2.879×(dry tensile strength in paper horizontal direction)+6.55×(wet tensile strength in paper horizontal direction)+5.36  (Equation 1)

Slip sensory evaluation value E.sub.s=−8.80×(dynamic friction coefficient)−0.41×(arithmetic mean surface roughness)+13.58  (Equation 2)

A formation detection system comprising: (a) one or more sensors and (b) one or more lights that illuminate a location of interest so that the one or more sensors can monitor the location of interest; wherein one of the one or more sensors are located substantially planar with a wire of a paper machine and proximate to a slice opening so that the one of the one or more sensors is adjacent to a cut through so that the one of the one or more sensors is capable of measuring stock above the wire and removed water below the wire, and wherein the one of the one or more sensors is capable of measuring a distance between an impingement location of a stock jet and the wire from a forming board.

The present invention relates to a cellulose filter paper for testing the ignition propensity of cigarette paper that is provided with a marking with which the rough surface of the filter paper can be distinguished from the smooth surface, and a method for its production, a method for testing the ignition propensity of cigarette paper, and a kit having a plurality of such filter papers or stacks of such filter papers.