摘要:
The invention relates to a process and an arrangement for producing a fiber web. In the process moist fiber web is guided from press section of a fiber web machine into drying arrangement that comprises in process direction one or more devices each having one or more belt like contact zones that comprise two smooth surfaces, first surface and second surface, between which surfaces the web is treated and which surfaces pressure-treat the web mechanically for heating the fiber web.
摘要:
A heating device according to the invention for heating at least one member of a processing apparatus in a pressing, drying and/or finishing section of a fibrous-web treatment machine is shown. The heating device comprises a primary heating cycle in which a primary heating medium is passed, a secondary heating cycle for heating the at least one member of the processing apparatus in which a secondary heating medium is circulated, and an indirect heat exchanging means for exchanging heat between the primary heating medium and the secondary heating medium. An amount of heat of the primary heating medium passing in the primary heating cycle is transferred to the secondary heating medium circulating in the secondary heating cycle by means of the indirect heat exchanging means so that the at least one member of the processing apparatus is heatable by the secondary heating medium. Furthermore, the heating device according to the invention is used in a processing apparatus of a pressing, drying and/or finishing section of a fibrous-web treatment machine for heating at least one member to be heated. Also, a method according to the invention for heating of at least one member of a processing apparatus in a pressing, drying and/or finishing section of a fibrous-web treatment machine is shown.
摘要:
The invention relates to a method for treating a coated or uncoated fibrous web with a sizing agent, wherein at least one sizing process for a fibrous web to be treated with a sizing comprises the use of a processing device (1), wherein a contact pressure applied to a web (W) is adjusted by the tension of a belt (2) and/or by means of a compression force applied to the design and/or the belt by press elements (4) optionally provided inside the belt loop to lie within the range of about 0.01 MPa to about 70 MPa, and in the method, the processing time of the fibrous web (W) in the processing zone of the metal belt calender (1) is adapted to be adjustable within the range of 10 to 1000 ms, and the belt comprises a metal belt, having a thickness of about 0,1 to 3 mm.
摘要:
The invention relates to a process for producing a fiber web in which process by surface sizing of the web sizing agent is applied onto the fiber web. The sizing agent comprises a mixture of at least two different starch solutions and that the fiber web is heated and/or dried before or after or during the surface sizing. The invention also relates to an arrangement for producing a fiber web. The arrangement for producing fiber web (W) comprises means (11) to apply sizing agent that comprises partially native starch on the surface of the fiber web and means (10; B) for heating and/or drying the web (W).
摘要:
The invention relates to process for treating a fiber web, especially a board web, in which process fiber web is guided into a processing zone that is created in between a belt (21) and at least one cylinder or roll (14, 16) and/or in between two belts (22, 23), in which processing zone the fiber web (w) is treated, advantageously calendered, during a dwell time. In the process the fiber web is treated in the processing zone for a long dwell time for at least 200 ms and in moderate temperatures in the range of 60 - 180 ºC. The processing zone comprises at least three stages in any order: a short-treatement stage, a loading stage and a long-treatment stage. In the short-treatment stage the dwell time is less than 200 ms and the load is 0,01- 10 MPa. In the loading stage the dwell time is 1 ― 20 ms and the load is 0,1 ― 100 MPa. In the long-treatment stage the dwell time is more than 100 ms and the load is 0,01 ― 10 MPa. The invention also relates to a device for treating a fiber web.
摘要:
The invention relates to a method for producing a fiber web (W), in which method the fiber web (W) is calendered in at least one calendering nip (NA; NB) of at least one calender (20A; 20B) and reeled up in a reel-up (40). The fiber web (W) is cooled by cooling means (10A; 10B) before calendering to temperatures of not higher than 40 °C, preferably to temperature in the range of 10 - 30 °C. The invention also relates to a production line for producing fiber webs (W), which comprises at least one calender (20A; 20B) with at least one calendering nip (NA; NB) and a reel-up (40) after the calender (20A; 20B). The production line comprises at least one cooling means (10A; 10B) before the at least one calender (20A; 20B) for cooling the fiber web to temperatures of not higher than 40 °C, preferably to temperature in the range of 10-30 °C.
摘要:
The invention relates to a processing device for processing a coated or uncoated fibrous web, comprising a belt (2) adapted to extend around a guiding element (3), at least one roll (5) being disposed outside said belt to provide a contact area with the belt, such that the belt (2) and the roll (5) establish therebetween a web processing zone for passing a web to be processed therethrough, wherein outside the belt (2) is provided a deflection-compensated nip roll (26) to establish a profiling nip with the roll (5), a web (W) being adapted to travel through said profiling nip, that the processing zone length is defined by means of the disposition/adjustment of the belt's (2) guiding element (3) and/or by means of the dimensioning of the roll (5), and that a contact pressure applied to the web in the processing zone is adapted to be adjustable within the range of about 0.01 MPa to about 200 MPa, and that the roll (5) comprises a thermal roll, that the belt (2) comprises a metal belt, and that the operating temperature of the thermal roll (5) and/or the metal belt lies within the range of about 50°C to about 400°C, and the belt having a thickness of about 0,1 to 3 mm.
摘要:
The invention relates to a processing device for processing a coated or uncoated fibrous web, comprising a belt (2) adapted to extend around at least one guiding element (3), at least one counter-element (5) being disposed outside said belt to provide a contact area with the belt, such that the belt (2) and the counter-element (5) establish therebetween a web processing zone for passing a web to be processed therethrough, wherein the processing zone length is defined by means of the disposition/adjustment of the belt's (2) guiding element (3) and/or by means of the design of said at least one counter-element (5), and that a contact pressure applied to the web in the processing zone is adapted to be adjustable within the range of about 0.01 MPa to about 200 MPa, and that the roll (5) comprises a thermal roll, that the belt (2) comprises a metal belt, and that the operating temperature of the thermal roll (5) and/or the metal belt lies within the range of about -70°C to about 400°C, and the belt comprises a metal belt, having a thickness of about 0,1 to 3 mm.
摘要:
The invention relates to a method for producing a fiber web, in which water resistance of the fiber web is increased by decreasing water solubility of sizing agent used for production of the fiber web by using as sizing agent starch originating from grain or by using a chemical additive in the sizing agent which chemical additive creates bonds with reactive groups of the sizing agent and cross-links and/or decreases water solubility, in particular with an insolubilizer. The invention also relates to a method for producing a fiber web, in which a multilayer sizing process is used in which sizing agent is applied on the fiber web in at least two stages so that a layered sizing profile is achieve in the thickness direction and that in the multilayer sizing process the layers of sizing agent comprise in different layers sizing agents of at least two different compositions. The invention further relates to a process for producing a fiber web comprising sizing of the fiber web by sizing agent. In the sizing the sizing agent is provided in at least two stages of sizing to create a multilayer profile of the sizing agent onto the fiber web and that for at least one layer of the multilayer profile a sizing agent with decreased water solubility is used.