Press Belt in a Paper-Making Machine

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.

1 - 15 . (canceled) 
     
     
         16 . A press belt for a shoe-press device for dewatering or smoothing a fibrous web, the press belt comprising:
 a fiber-reinforced plastic matrix forming the press belt, said fiber-reinforced plastic matrix, at least in a part-region thereof, containing at least one polyurethane material and additives of polydimethyl siloxane and silicon dioxide microparticles.   
     
     
         17 . The press belt according to  claim 16 , wherein at least one further part-region of said fiber-reinforced plastic matrix is configured as foam. 
     
     
         18 . The press belt according to  claim 16 , wherein the at least one part-region is selected from the group consisting of a layer of the press belt, a surface layer of the press belt, a peripheral region of the press belt, and an inner layer of the press belt. 
     
     
         19 . The press belt according to  claim 16 , wherein said polydimethyl siloxane has a viscosity of between 100 and 100,000 mPa*s. 
     
     
         20 . The press belt according to  claim 16 , wherein said at least one part-region contains a proportion of said polydimethyl siloxane of 1 to 10% by weight. 
     
     
         21 . The press belt according to  claim 16 , wherein said silicon dioxide microparticles have a mean particle size of between 10 and 800 μm. 
     
     
         22 . The press belt according to  claim 16 , wherein said at least one part-region contains a proportion of said silicon dioxide microparticles of 1 to 10% by weight. 
     
     
         23 . The press belt according to  claim 16 , wherein said at least one part-region contains silicon dioxide nanoparticles having a mean particle size of between 10 and 80 nm. 
     
     
         24 . The press belt according to  claim 23 , wherein said at least one part-region contains a proportion of said silicon dioxide nanoparticles of 1 to 10% by weight. 
     
     
         25 . The press belt according to  claim 16 , wherein said at least one polyurethane material is made from at least from a polyurethane prepolymer and a cross-linking agent, and said polyurethane prepolymer is an MDI prepolymer and/or a PPDI prepolymer having a polyol component selected from the group consisting of polyether and polycarbonates. 
     
     
         26 . The press belt according to  claim 25 , wherein said cross-linking agent contains at least one polyether polyol material or is composed thereof. 
     
     
         27 . The press belt according to  claim 16 , configured for processing paper web, cardboard web, or tissue web. 
     
     
         28 . A method of manufacturing a plastic matrix for a press belt, the method comprising forming the plastic matrix from at least one polyurethane prepolymer, at least one cross-linking agent, polydimethyl siloxane, and silicon dioxide microparticles. 
     
     
         29 . The method according to  claim 28 , which comprises, prior to cross-linking the at least one polyurethane prepolymer, mixing silicon dioxide nanoparticles containing at least part of the cross-linking agent to form a nanoparticle mixture containing between 20% and 60% by weight of silicon dioxide nanoparticles. 
     
     
         30 . The method according to  claim 28 , which comprises, in downstream method steps, replacing the cross-linking agent with the nanoparticles mixture entirely or by 5 to 40%. 
     
     
         31 . The method according to  claim 28 , which comprises, prior to cross-linking the at least one polyurethane prepolymer, mixing the silicon dioxide microparticles with the polydimethyl siloxane and, optionally, with further additives, to form an additive mixture that is subsequently mixed with at least part of the cross-linking agent.