Patents by Inventor Pentti Lehtonen

Pentti Lehtonen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6609996
    Abstract: A press roll such as the center roll of a press or the back-up roll of an extended-nip press roll, used in a pulp, paper, board or finishing machine, has a coating with an intermediate sealed layer. The corrosion resistance and impermeability of the roll coating, particularly of such a coating that is made by thermal spraying, can be improved by way of sealing. The coating comprises a porous outermost surface layer made out of a ceramic or ceramic-metal material applied by thermal spraying and at least one sealed layer situated between the outermost surface layer and the roll mantle.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: August 26, 2003
    Assignee: Metso Paper, Inc.
    Inventors: Kari Niemi, Bjarne Hellman, Juha Wahlroos, Pentti Lehtonen
  • Patent number: 6500308
    Abstract: A coated press or transfer belt and method for coating a press or transfer belt is disclosed, wherein a coating of one or more polymers and possible blend components and additives is formed on the surface of the belt. Coating is carried out by rotational molding, which is, as such known, onto the belt rotating on one or more rolls from at least two rapidly reacting liquid components. The set coating layer is then ground to an even thickness.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: December 31, 2002
    Assignee: Metso Paper, Inc.
    Inventors: Pentti Lehtonen, Marko Kovanen
  • Patent number: 6461687
    Abstract: A roll for use in the manufacture of paper and board, a press roll, in particular a center roll in a press, a backup roll for an extended-nip press roll, a hot press roll, or equivalent, which is in direct contact with a wet paper web, or a calender roll, a method for manufacturing the same and a coating composition therefor including an adhesion layer arranged on the frame part of the roll and a ceramic layer arranged on the adhesion layer. The ceramic layer has a thickness of from about 100 &mgr;m to about 2000 &mgr;m and includes from about 50% to about 95% by weight of Cr2O3 and from about 3% to about 50% by weight of TiO2, or from about 50% to about 80% by weight of Al2O3 and from about 20% to about 50% by weight of ZrO2, or exclusively Al2TiO5. The outer face of the ceramic layer is finished until the roughness Ra is from about 0.2 &mgr;m to about 2.0 &mgr;m and/or the porosity of the outer face of the roll is from about 1% to about 20%.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: October 8, 2002
    Assignee: Metso Paper, Inc.
    Inventors: Juhani Vestola, Kari Niemi, Juha Wahlroos, Pentti Lehtonen, Jorma Majava, Jussi Tuomela, Harri Kuosa
  • Patent number: 6423185
    Abstract: The invention concerns a process for treatment of faces that contain chromium or aluminum in a paper/board machine or in a finishing machine. A fluorine compound of low surface energy is applied onto the face, which compound is made to adhere to the chromium or aluminum atoms in the face.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: July 23, 2002
    Assignee: Metso Paper, Inc.
    Inventors: Tapio Mäntylä, Pentti Lehtonen, Petri Sorsa
  • Publication number: 20020066405
    Abstract: A press roll such as the center roll of a press or the back-up roll of an extended-nip press roll, used in a pulp, paper, board or finishing machine, has a coating with an intermediate sealed layer. The corrosion resistance and impermeability of the roll coating, particularly of such a coating that is made by thermal spraying, can be improved by way of sealing. The coating comprises a porous outermost surface layer made out of a ceramic or ceramic-metal material applied by thermal spraying and at least one sealed layer situated between the outermost surface layer and the roll mantle.
    Type: Application
    Filed: August 13, 2001
    Publication date: June 6, 2002
    Inventors: Kari Niemi, Bjarne Hellman, Juha Wahlroos, Pentti Lehtonen
  • Publication number: 20010024723
    Abstract: A roll for use in the manufacture of paper and board, a press roll, in particular a center roll in a press, a backup roll for an extended-nip press roll, a hot press roll, or equivalent, which is in direct contact with a wet paper web, or a calender roll, a method for manufacturing the same and a coating composition therefor including an adhesion layer arranged on the frame part of the roll and a ceramic layer arranged on the adhesion layer. The ceramic layer has a thickness of from about 100 &mgr;m to about 2000 &mgr;m and includes from about 50% to about 95% by weight of Cr2O3 and from about 3% to about 50% by weight of TiO2, or from about 50% to about 80% by weight of Al2O3 and from about 20% to about 50% by weight of ZrO2, or exclusively Al2TiO5. The outer face of the ceramic layer is finished until the roughness Ra is from about 0.2 &mgr;m to about 2.0 &mgr;m and/or the porosity of the outer face of the roll is from about 1% to about 20%.
    Type: Application
    Filed: March 12, 2001
    Publication date: September 27, 2001
    Inventors: Juhani Vestola, Kari Niemi, Juha Wahlroos, Pentti Lehtonen, Jorma Majava, Jussi Tuomela, Harri Kuosa
  • Patent number: 6167623
    Abstract: A press roll for a paper or board machine, a method for manufacturing a roll for a paper or board machine and a coating composition for a roll which enable the roll to endure difficult corrosion conditions. An adhesion/corrosion-protection layer having a thickness of from about 150 &mgr;m to about 300 &mgr;m is applied onto the frame part of the roll by a high-velocity flame spraying technique. The adhesion/corrosion-protection layer contains a nickel-chromium alloy. A tight-ceramic layer having a thickness from about 50 &mgr;m to about 150 &mgr;m is applied onto the adhesion/corrosion-protection layer by a high-velocity flame spraying technique and includes from about 50% to about 100% of Al2O3 and optionally includes up to about 50% of TiO2 and/or any amount of Al2TiO5. A porous ceramic layer is applied onto the tight ceramic layer. The tight-ceramic layer may include only Al2TiO5 instead of Al2O3, with or without TiO2.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: January 2, 2001
    Assignee: Valmet Corporation
    Inventors: Kari Niemi, Juha Wahlroos, Pentti Lehtonen
  • Patent number: 5967959
    Abstract: A press roll for a paper or board machine, a method for manufacturing a roll for a paper or board machine and a coating composition for a roll which enable the roll to endure difficult corrosion conditions. An adhesion/corrosion-protection layer having a thickness of from about 150 .mu.m to about 300 .mu.m is applied onto the frame part of the roll by a high-velocity flame spraying technique. The adhesion/corrosion-protection layer contains a nickel-chromium alloy. A tight-ceramic layer having a thickness from about 50 .mu.m to about 150 .mu.m is applied onto the adhesion/corrosion-protection layer by a high-velocity flame spraying technique and includes from about 50% to about 100% of Al.sub.2 O.sub.3 and optionally includes up to about 50% of TiO.sub.2 and/or any amount of Al.sub.2 TiO.sub.5. A porous ceramic layer is applied onto the tight ceramic layer. The tight-ceramic layer may include only Al.sub.2 TiO.sub.5 instead of Al.sub.2 O.sub.3, with or without TiO.sub.2.
    Type: Grant
    Filed: April 8, 1998
    Date of Patent: October 19, 1999
    Assignee: Valmet Corporation
    Inventors: Kari Niemi, Juha Wahlroos, Pentti Lehtonen
  • Patent number: 5553381
    Abstract: A roll and a method for coating a roll in a paper machine with powder of thermo-plastic and/or specialty plastic. The coating is carried out by spraying by using hyper-sonic plasma.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: September 10, 1996
    Assignee: Valmet Corporation
    Inventor: Pentti Lehtonen
  • Patent number: 5176940
    Abstract: The invention concerns a roll or cylinder or roll coating for a pulp machine, paper machine, or paper finishing machine, in which application the roll or equivalent comprises a cylinder mantle of cast iron or steel or any other, equivalent metal, which bears the mechanical loads. On the rollor cylinder mantle, fixed to the outer face of the frame mantle, there is a resilient polymer coating, and onto said polymer coating a coating is fixed which is by several orders thinner than the radial thickness of the polymer coating. Said coating fixed onto the outer face of the polymer coating is a metal, ceramic, or cermet coating or a plastic coating. The invention further concerns a method for the manufacture of a roll coating in accordance with the invention as well as the use of such rolls and coatings.
    Type: Grant
    Filed: February 5, 1991
    Date of Patent: January 5, 1993
    Assignee: Valmet Paper Machinery Inc.
    Inventors: Jukka Salo, Pentti Lehtonen
  • Patent number: 5023985
    Abstract: A roll for a pulp machine, paper machine, or paper finishing machine with a cylinder mantle of cast iron or steel, or any other equivalent metal, which bears the mechanical loads. On the roll mantle, fixed to the outer face of the mantle, there is a resilient polymer coating, and onto the polymer coating a coating is fixed which is by several orders thinner than the radial thickness of the polymer coating. This coating fixed onto the outer face of the polymer coating is a metal, ceramic, cermet or plastic coating.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: June 18, 1991
    Assignee: Valmet Paper Machinery Inc.
    Inventors: Jukka Salo, Pentti Lehtonen