Abstract: A ply for a paper and paperboard made from a ply substrate material, wherein the ply comprises a hybrid material, in an amount of 1-25 wt-% of the ply, wherein the hybrid material is introduced into a target suspension of the short circulation of a fibrous web forming process of a fibrous web machine, in an in-line process, wherein said target suspension forms the ply substrate material, and the hybrid material comprises an alkaline earth carbonate precipitated onto or into fibers or fibrils of a nanofibrillated polysaccharide.

Abstract: An in-line production method for providing a liquid flow of at least one additive in the short circulation and into the liquid flow of a paper making stock of a fiber web machine by feeding, the liquid flow of the at least one additive to the liquid flow of the short circulation, wherein a suitable amount of a microfibrillated cellulose or nanofibrillated polysaccharide is provided substantially simultaneously with the feeding of liquid flow of the at least one additive.

Abstract: A method for mixing a chemical into a process liquid including: injecting the chemical into the process liquid flowing through a flow pipe; forming reaction products by a reaction involving the chemical occurring in the process flow; applying an electric field or magnetic field to a region of the flow pipe adjacent to the reaction occurring in the process flow, and suppressing the precipitation of the chemical or the reaction products on the surfaces of the pipe due to the electric or magnetic field.

Abstract: A method including: introducing a first chemical to a first passage of a mixing apparatus attached to the process liquid flow pipe; introducing an injection liquid into a second passage of the mixing apparatus; introducing to a third passage of the mixing apparatus a second chemical having an electrical charge opposite to the electric charge of the first chemical; injecting the first chemical into the injection liquid by passing the first chemical through a passage between the first passage and the second passage; introducing the mixture of the first chemical and the injection liquid to a process liquid flowing through the process liquid flow pipe, and introducing the second chemical from the third passage to the process liquid in the process liquid flow pipe, wherein the second chemical passes from the third passage to the process liquid a distance from the injection of the first chemical into the injection liquid.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

Abstract: A method to feed a chemical into a liquid flow using a feed device including a nozzle casing having an isolated mixing space including: feeding the chemical to the isolated mixing space in the feed device; feeding a mixing liquid to the isolated mixing space; mixing the chemical and the mixing liquid in the isolated mixing space to form a mixture of chemical and mixing liquid, and feeding the mixture of chemical and mixing liquid to the liquid flow.

Abstract: Methods are provided for crystallizing a filler, especially in order to precipitate calcium carbonate on the surfaces of solids in the short circulation of a fiber web machine by feeding carbon dioxide and lime milk to the liquid flow of the short circulation and allowing them to react with one another, is characterized in that the feed system, the mixing method and/or mixing rate of the chemicals are selected such that a size distribution of the calcium carbonate crystals suitable for the purpose is obtained. Moreover, the invention relates to an approach system for a fiber web machine applying this method, characterized in that it is provided with devices for feeding and mixing carbon dioxide and lime milk into the liquid flow at such a rate that the applicable size distribution of the calcium carbonate crystals is obtained.

Abstract: A feeding device for feeding a chemical into a process liquid flowing through a process liquid flow duct, the feeding device includes: a feeding liquid duct having a discharge opening; a mixing liquid feed duct extending through the feeding liquid duct, a sidewall and a closed end wall, wherein the end wall extends beyond the discharge opening of the feeding liquid duct and extending into the process liquid flow duct; a mixing space adjacent the end wall and within the sidewall of the mixing liquid feed duct; a chemical feed duct extending through the mixing liquid feed duct and having a discharge opening proximate to the mixing space in the mixing liquid feed duct, and a mixture discharge opening in the side wall of the mixing liquid feed duct.

Abstract: Methods are provided for crystallizing a filler, especially in order to precipitate calcium carbonate on the surfaces of solids in the short circulation of a fiber web machine by feeding carbon dioxide and lime milk to the liquid flow of the short circulation and allowing them to react with one another, is characterized in that the feed system, the mixing method and/or mixing rate of the chemicals are selected such that a size distribution of the calcium carbonate crystals suitable for the purpose is obtained. Moreover, the invention relates to an approach system for a fiber web machine applying this method, characterized in that it is provided with devices for feeding and mixing carbon dioxide and lime milk into the liquid flow at such a rate that the applicable size distribution of the calcium carbonate crystals is obtained.

Abstract: A method and apparatus for in-line production of milk of lime into an in-line production process of PCC arranged in connection with a fibrous web machine. In the solution, lime is slaked in a slaking apparatus at a temperature of at least 80 degrees. The produced milk of lime is cleaned by separating excessively large calcium hydroxide particles immediately prior to introducing the milk of lime into the production process of PCC. The milk of lime is introduced into the in-line production process of PCC located in the production line of the end or intermediate product of the fibrous web machine.

Abstract: The method of the present invention for crystallizing a filler, especially in order to precipitate calcium carbonate on the surfaces of solids in the short circulation of a fiber web machine by feeding carbon dioxide and lime milk to the liquid flow of the short circulation and allowing them to react with one another, is characterized in that the feed system, the mixing method and/or mixing rate of the chemicals are selected such that a size distribution of the calcium carbonate crystals suitable for the purpose is obtained. Moreover, the invention relates to an approach system for a fiber web machine applying this method, characterized in that it is provided with devices for feeding and mixing carbon dioxide and lime milk into the liquid flow at such a rate that the applicable size distribution of the calcium carbonate crystals is obtained.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

Abstract: A method of introducing a first flow and a second flow into a process liquid flowing through a conduit including: injecting the first flow with an introduction liquid into the process liquid in transverse to a flow direction of the process liquid, wherein the injected first flow forms a mixing field comprising counter-rotating vortices in the process liquid; and injecting a second flow transverse to the flow direction of the process liquid and between the counter-rotating vortices.

Abstract: A method for mixing a chemical into a process liquid including: injecting the chemical into the process liquid flowing through a flow pipe; forming reaction products by a reaction involving the chemical occurring in the process flow; applying an electric field or magnetic field to a region of the flow pipe adjacent to the reaction occurring in the process flow, and suppressing the precipitation of the chemical or the reaction products on the surfaces of the pipe due to the electric or magnetic field.

Abstract: A method of feeding chemical to a liquid in an open space or flowing in an open space so that the chemical is fed to the liquid by means of a special mixing device or several special mixing devices by means of feed liquid introduced to the mixing device separately from the chemical by allowing the chemical and the feed liquid to discharge essentially simultaneously through the nozzle opening of the mixing device, the opening being located under the liquid level in the space, to the liquid in the space or flowing in the space.

Abstract: The present invention relates to a method and an arrangement for proportioning thick stock to a short circulation of a fiber web machine. Specifically, the method and the arrangement of the invention relate to treating and proportioning thick stock components of paper making stock having a consistency of the order of 2-12%, preferably 2-5%, for instance into white water one component after another alone or together with an additive.

Abstract: A method of mixing at least two chemicals or additives into a process liquid flow flowing in a process liquid flow duct including: feeding a liquid jet to the process liquid flow in the process liquid flow duct, wherein the liquid jet is formed in a feeding device and the liquid jet flows in a transverse direction to a flow direction of the process liquid flow through the process liquid flow duct; mixing the at least two chemicals or additives together to form a mixture; feeding the mixture of the at least two chemicals or additives into the process liquid flow duct with the feeding liquid jet, and mixing the at least two chemicals or additives with the feeding liquid jet in the process liquid flow duct.

Abstract: The present invention relates to a method and an arrangement for proportioning thick stock to a short circulation of a fiber web machine. Specifically, the method and the arrangement of the invention relate to treating and proportioning thick stock components of paper making stock having a consistency of the order of 2-12%, preferably 2-5%, for instance into white water one component after another alone or together with an additive.

Abstract: The method of the present invention for crystallizing a filler, especially in order to precipitate calcium carbonate on the surfaces of solids in the short circulation of a fiber web machine by feeding carbon dioxide and lime milk to the liquid flow of the short circulation and allowing them to react with one another, is characterized in that the feed system, the mixing method and/or mixing rate of the chemicals are selected such that a size distribution of the calcium carbonate crystals suitable for the purpose is obtained. Moreover, the invention relates to an approach system for a fiber web machine applying this method, characterized in that it is provided with devices for feeding and mixing carbon dioxide and lime milk into the liquid flow at such a rate that the applicable size distribution of the calcium carbonate crystals is obtained.

Abstract: A method of and apparatus for feeding a chemical into a liquid flow are especially suited for use with a headbox of a paper machine, particularly for feeding a retention aid into a fiber suspension flow going to the headbox so that in a mixing apparatus feed liquid is added into the retention chemical solution, prior to introducing the solution into the fiber suspension flow guided to the paper machine. The feed liquid is preferably a circulation water from the paper mill, or another non-clean liquid from a paper mill.