The current method relates to an on-line characterization of paper or paper products, such as tissue or other crepe paper products. The method uses an imaging source wherein one or more images are obtained of the sheets surface or topographical area or region, or the image is of an edge of a formed sheet. The one or more images are enhanced and analyzed using various techniques and metrics for characterizing the structure of the formed sheet. The information provides for real time adjustments on the machine.

A creping blade and a preparation method thereof are provided. The creping blade comprises a base, wherein a wear-resistant coating is provided on the top of the base, and a protective layer is arranged below the wear-resistant coating at the contact point between the creping blade and a dryer, and the hardness of the protective layer is lower than that of the surface of the dryer of a paper machine. The creping blade of the invention is advantageous in that the friction portion of working surface has an unlimited area and has a high wear-resistant coating, and the paper impact portion has high wear resistance and high impact resistance, so that the creping blade has a long service life, which can be several times or even tens of times that of the common steel creping blade.

A blade for creping a paper web from a dryer cylinder surface. The blade has a leading side and a front bevel surface to be impacted by the paper web. The leading side and the front bevel surface meet at a contact edge to contact the dryer cylinder. The front bevel surface has a 3D areal roughness, measured according to ISO 25178, of Sa>0.7 ?m and/or Sz>18 ?m and/or Sq>1.0 ?m.

A blade for creping a paper web from a Yankee cylinder surface is made of a steel substrate having a thickness of 0.7 mm-2 mm. The steel substrate is covered by a cermet coating that forms a working edge adapted for contact with the surface and a web impact area upon which the web impacts during creping. The cermet coating includes chromium carbides and tungsten carbides in a nickel based metal matrix. The cermet coating has a porosity of <2 volume % and a hardness of >1100 HV.sub.0.3.

The doctor blade holder (7) comprises: a plurality of fingers (35) mounted on a beam (9), hinged around a rotation axis (37A) and configured to cumulatively form a housing seat (41) for the doctor blade (43); wherein the fingers (35) are pivotable independently from one another around said rotation axis (37A); at least one actuator (51) comprising at least one chamber (53) that can be inflated with pressurized fluid, configured and arranged so as to generate a thrust (f53) on the fingers (35) to make them pivot around said rotation axis (37A).

Each finger (35) can be mounted and removed independently from the others on said beam (9).

There is described a doctor blade holder (7) for a doctor blade (43) adapted to co-act with a cylindrical surface (1S) of a rotating cylinder (1), comprising: a plurality of fingers (35) mounted on a beam (9), hinged around a rotation axis (37A) and configured to cumulatively form a housing seat (41) for the doctor blade (43); wherein the fingers (35) are pivotable independently from one another around said rotation axis (37A); at least one elastic thrust member (51), configured and arranged to generate a thrust on the fingers ((35) to make them pivot around said rotation axis (37A).

Each finger (35) comprises a locking element (67), to rigidly lock the finger to the beam (9).

A blade for creping a paper web from a dryer cylinder surface. The blade has a leading side and a front bevel surface to be impacted by the paper web. The leading side and the front bevel surface meet at a contact edge to contact the dryer cylinder. The front bevel surface has a 3D areal roughness, measured according to ISO 25178, of Sa>0.7 m and/or Sz>18 m and/or Sq>1.0 m.

A creping blade having a first side face, a second side face, and a shelf extending from the first side face to the second side face, with a scraping edge at the intersection of the first side face and the shelf. The shelf has a first section having a first coefficient of friction and a second section have a second coefficient of friction and the second coefficient of friction is greater than the first coefficient of friction.

The invention relates to a creping blade for the detachment of a travelling paper web from a dryer cylinder, said blade having a working edge to be placed against the cylinder, wherein the creping blade has a tensile strength of 1800-2500 N/mm.sup.2 and a hardness of 57-66 HRC in the hardened and tempered condition and wherein the blade is made from a steel, which comprises the following main components (in wt. %): C: 1.2-1.5; Si: 0.1-0.8; Mn: 0.1-0.7; Cr: 4.2-5.2; Mo: 3.0-4.0; V: 3.2-4.2; N: 0.01-0.15; balance Fe and impurities.

A method of creping a web including supporting the web on a drum and rotating the drum to move a first length of the web proximate to a creping blade such that the creping blade removes the first length from the drum. The creping blade has first and second sections made of a base material. The base material has a first coefficient of friction at the first section and is processed to produce a second coefficient of friction at the second section greater than the first coefficient of friction. The method includes moving the first length along the first section, removing a second length of the web from the drum with the creping blade, moving the first length along the second section, forming the second length into at least one microfold as the first length contacts the second section, and forming the second length into at least one macrofold.