A calender roll for a papermaking machine includes: a substantially cylindrical core; and a cover circumferentially surrounding the core. The cover comprises a base layer circumferentially overlying the core; and a topstock layer comprising polyurethane circumferentially overlying the base layer, the topstock layer being fiber reinforced, the polyurethane having a glass transition temperature of between about 120 and 150 C., the topstock layer having a hardness of 70 to 90 ShD.

Calender for treating web materials, comprising a structure for supporting two heated rollers forming a nip, wherein each roller has surface reliefs (RR) and in an operational setting of the calender the reliefs of one roller are radially opposed to those of the other roller, each roller rotates with a predetermined angular speed around its axis, the rollers are heated by heating means, and each roller undergoes an axial elongation as a consequence of its heating. The calender comprises detection means (E1, E2; IS) adapted to detect the axial elongation of each roller and a programmable control unit (UCP) connected to the detection means and to the heating means. The control unit is programmed to determine the difference between the axial elongations of the rollers and emitting an alarm signal if the absolute value of this difference is greater than a limit value.

A deflection compensated roll, comprising a shaft, a shell configured to rotate around the shaft, one or more loading units between the shaft and the shell configured to adjust a nip load profile. The loading unit comprising a pressure chamber, a seal configured to seal the pressure chamber with pressurized gas, and a flexible mounting configured to mount the seal 4 flexibly on the shaft. Also, a method for controlling a nip load with a deflection compensated roll is disclosed.

The present invention relates to a roll for use in a manufacture of a fibrous web comprising cellulosic fibers. The roll comprises a roll body with a cylindrical surface, and a roll cover, which is arranged to cover the cylindrical surface of the roll body. The cover comprises a functional layer, which comprises a polymer matrix and filler particles embedded in the polymer matrix. The filler particles comprise hollow spherical particles of aluminium oxide, titanium oxide, zirconium oxide and/or silicon carbide, which hollow particles have a particle size of 200 m.

The present invention relates to a roll for use in a manufacture of a fibrous web comprising cellulosic fibers. The roll comprises a roll body with a cylindrical surface, and a roll cover, which is arranged to cover the cylindrical surface of the roll body. The cover comprises a functional layer, which comprises a polymer matrix and filler particles embedded in the polymer matrix. The filler particles comprise hollow spherical particles of aluminium oxide, titanium oxide, zirconium oxide and/or silicon carbide, which hollow particles have a particle size of 200 m.

An industrial roll includes: a substantially cylindrical metallic core; a rubber base layer that is adhered to and circumferentially overlies the core; a rubber top stock layer that circumferentially overlies the base layer; and a polyurethane coating that circumferentially overlies the top stock layer. In this configuration, the roll can provide improved abrasion-resistance, sheet release properties, and/or toughness compared to a roll with a rubber cover, but may provide these properties in a cover that is softer than a typical polyurethane cover.

A heatable roller suitable for a machine for producing and/or upgrading a web of material, in particular a fibrous material web such as a paper, paperboard or tissue web. The roller has a main element with a metallic and cylindrical roller wall which is heatable by suitable means and on the radially outer side of which there is, at least in sections, a coating. When the roller is used as intended, the coating provides a web contact side which can be brought into contact with the web of material. The coating includes, or is formed by, at least one metallic or metal-carbidic layer with a first layer component providing a matrix and a second layer component distributed in the matrix. The first layer component has a higher abrasion resistance than the second layer component and the second layer component has a greater thermal conductivity than the first layer component.

Calender for the treatment of web-like materials, including a fixed structure supporting two heated rollers reciprocally arranged so as to form a nip traversable by web-like materials, where each roller has pins mounted on bearings. The structure includes two lower levers and two upper levers adapted for exerting on the bearings forces oriented according to not coinciding directions, each lever being connected with an actuator that controls its rotation around a horizontal axis to put it in a first engagement position of the respective bearing and in a second release position, such that in the second position of the levers the extraction of the rollers from the calender is allowed.

The present invention for eliminating a need for a temperature detecting element adapted to measure the temperature of a roll main body provides an induction heated roll apparatus including: a roll main body; a magnetic flux generating mechanism including an iron core and a winding; and a power supply circuit provided with a control element adapted to control AC current or AC voltage. The apparatus calculates the temperature of the roll main body using an AC current value obtained by an AC current detecting part, an AC voltage value obtained by an AC voltage detecting part, a power factor obtained by a power factor detecting part, a winding resistance value of the winding, and an excitation resistance obtained from characteristics of a relationship between a magnetic flux density and an excitation resistance of a magnetic circuit including the iron core and the roll main body as parameters.

A roll cover is particular suited for use in an apparatus for producing or surface finishing a fibrous web, such as a web of paper or of cardboard. The roll cover is formed on a roll core of metal or of a fiber-reinforced plastic and includes a matrix system wherein fillers are provided. The fillers provided are three or more in number and they have different median particle sizes.