Abstract: A press cover for a press roll or a transport belt has at least one polyurethane-containing layer. The polyurethane is obtainable by reaction of i) a polyol component, ii) an isocyanate component, and iii) a component containing at least one crosslinker. The polyol component is composed of mutually different structural units having the general formula —O—R1—X—R2—O— in which all of R1 and R2 independently of one another are identical or different and are linear or branched C1-C20 alkylene groups. Groups X are identical or different and are selected from bond, O, C(O)—O, and O—C(O)—O. At least 70 wt % of the structural units meet the following criteria: a) at least 80% of X are O—C(O)—O and the remainder are O or C(O)—O, and b) the average chain length of R1 and R2 is 8 or more carbon atoms, and c) at least 50% of R1 and R2 are independently of one another a linear or branched C8-C12 alkylene group.

Abstract: A press cover is formed with at least one polymer layer. The at least one polymer layer includes or is formed of at least one thermoplastic elastomer in the form of a copolymer. There is also disclosed the use of a press cover of this type in a shoe press, a shoe press of this type, and a press roll, in each case having a press cover of this type. Finally, there is also disclosed the use of a thermoplastic elastomer in the form of a copolymer, for at least one polymer layer of a press cover for a shoe press for the treatment of a fibrous web.

Abstract: A press cover or jacket includes at least a first and a second polymer layer. The first polymer layer is a radially outermost polymer layer as seen relative to the longitudinal axis of the press cover and has a thickness that is at most 60% of the overall thickness of the press cover as seen in the radial direction of the press cover. The first polymer layer includes grooves or holes which are incorporated in the radially outermost lateral surface thereof and the depth of the grooves or holes, as seen in the radial direction of the press cover, have a depth that corresponds at most to 95% of the thickness of the first polymer layer. A press roll, a shoe press and a method of using a press cover are also provided.

Abstract: The invention relates to a press jacket comprising at least one polymer layer, where the polymer layer comprises, or has been produced from, a polyurethane, where the polyurethane has been formed from a prepolymer and a crosslinking agent, and the prepolymer is a reaction product of phenylene 1,4-diisocyanate and of a polyol, where the crosslinking agent comprises the following components: a first component comprising 1,4-butanediol or 1,4-hydroquinone bis(2-hydroxyethyl) ether (HQEE), a second component comprising at least one aliphatic diamine, a third component comprising at least one alkanolamine.

Abstract: A press cover has at least one polymer layer. The polymer layer includes, or is produced from, a polyurethane. The polyurethane has been formed from a prepolymer and a crosslinker. The prepolymer is a reaction product of phenylene 1,4-diisocyanate and at least one polyol. The crosslinker includes at least two components, namely, a first component having at least one diamine and a second component from the group of the carbonic esters.

Abstract: A press cover includes at least one polymer layer. The polymer layer contains or has been produced from a polyurethane. The polyurethane has been formed from a prepolymer and a crosslinker, and the prepolymer is a reaction product of phenylene 1,4-diisocyanate and at least one polyol containing caprolactone and carbonate, such as polycaprolactone polycarbonate polyol. A press roll, a shoe press and a method of using a press cover are also provided.

Abstract: A press cover or jacket includes at least one first polymer layer. The polymer layer contains or has been produced from a polyurethane, and the polyurethane has been formed from a prepolymer and a crosslinker. The prepolymer is a reaction product of naphthalene 1,5-diisocyanate or phenylene 1,4-diisocyanate and at least one polyol selected from a polycarbonate polyol, a polytetramethylene ether glycol, polyether polycarbonate polyol or mixtures thereof. A press using the press cover is also provided.

Abstract: A press jacket includes at least one polymer layer. The polymer layer includes, or has been produced from, a polyurethane. The polyurethane has been formed from a prepolymer and a cross linking agent. The prepolymer is a reaction product of phenylene 1,4-diisocyanate and a polyol. The cross linking agent includes the following components: a first component including 1,4-butanediol or 1,4-hydroquinone bis(2-hydroxyethyl) ether (HQEE), a second component including at least one aliphatic diamine, and a third component including at least one alkanolamine. A press roll, a shoe press and a process for the production of a press jacket are also provided.

Abstract: A press jacket for a press roller, in particular for a press roller of a shoe press for dewatering a fibrous material web, in particular a paper, cardboard, tissue or pulp web, or a transport band, in particular for a machine for producing or treating a fibrous material web, in particular a paper, cardboard or tissue machine, includes at least one layer containing polyurethane which contains a polyurethane matrix with a mixture of at least two prepolymers. Each prepolymer is a reaction product of two different polyols with a polyisocyanate.

Abstract: A press belt for a shoe-press device for dewatering or smoothing a fibrous web, in particular a paper, cardboard, or tissue web. The press belt has a fiber-reinforced plastic matrix. On account of the fiber-reinforced plastic matrix containing at least in a partial region at least one polyurethane material and polydimethyl siloxane and silicon dioxide microparticles as additives, resistance to abrasion, the tendency toward developing fissures and toward fissure growth and/or resistance in relation to media present in a paper-making machine can be improved.

Abstract: The invention relates to a method for removing solid matter, in particular impurities, by means of flotation from a fibrous material suspension (S), wherein the fibrous material suspension (S) is mixed with gas (L), and wherein in at least two flotation chambers (1, 2, 2?, 2?, 2??, 2??) flotation foam (3, 4) is formed that collects solid matter and removes it from the flotation chamber. The flotation foam (4) of at least one flotation chamber (1, 2, 2?, 2?, 2??, 2??) is at least partially conducted into at least one other flotation chamber (1), in particular in the flotation foam (3) formed therein. According to the method, the complexity can be reduced, even with high requirements regarding effect and yield.

Abstract: The invention relates to a method for removing solid matter, in particular impurities, by means of flotation from a fibrous material suspension (S), wherein the fibrous material suspension (S) is mixed with gas (L), and wherein in at least two flotation chambers (1, 2, 2?, 2?, 2??, 2??) flotation foam (3, 4) is formed that collects solid matter and removes it from the flotation chamber. The flotation foam (4) of at least one flotation chamber (1, 2, 2?, 2?, 2??, 2??) is at least partially conducted into at least one other flotation chamber (1), in particular in the flotation foam (3) formed therein. According to the method, the complexity can be reduced, even with high requirements regarding effect and yield.