4results about "Slime-control agents addition" patented technology

A method for controlling papermaking, comprising: monitoring the liquid level of a fibrous suspension in a reservoir (302); identifying that the liquid level has dropped so as to meet at least one empty criterion (303), and then identifying that the liquid level has risen so as to meet at least one replenishment criterion; and starting to administer a biocide to the fibrous suspension flowing into the reservoir in response to identifying that the liquid level has risen so as to meet at least one replenishment criterion. A corresponding device and computer program are also disclosed.

The invention relates to a method for manufacturing a fibrous web, such as web of paper, board, tissue or the like. The method comprises forming an aqueous fibre suspension comprising cellulosic fibres from one or more raw material flows, and applying at least one chemical and / or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity, such as storage tower or broke tower, which has a delay time of at least one hour, preferably at least two hours. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension in the intermediate residence entity at least the minimum delay time, and a final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity but before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated, and if the ORP difference value exceeds a pre-determined threshold value, then adjusting the applied chemical and / or physical control measure(s) until the ORP difference value falls below the pre-determined threshold value. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

The invention relates to a method for manufacturing a fibrous web, such as web of paper, board, tissue or the like. The method comprises forming an aqueous fibre suspension comprising cellulosic fibres from one or more raw material flows, and applying at least one chemical and / or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity, such as storage tower or broke tower, which has a delay time of at least one hour, preferably at least two hours. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension in the intermediate residence entity at least the minimum delay time, and a final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity but before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated, and if the ORP difference value exceeds a pre-determined threshold value, then adjusting the applied chemical and / or physical control measure(s) until the ORP difference value falls below the pre-determined threshold value. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

A method of controlling volatile fatty acid (VFA) content in a pulp, paper, and / or board making processes is disclosed. The method may be used to provide process improvements in the form of reduced microbial contamination and odor, reduced starch degradation, optimized retention, and improved runability. The method includes treating a process flow comprising a cellulosic material comprising a starch with an enzymatic VFA control agent. The enzymatic VFA control agent is non-biocidal, may further comprise a surfactant or dispersant, and is utilized in an amount sufficient to inhibit microbiological production of one or more VFA. The method optionally includes treating the process flow with a biocidal agent in combination with the enzymatic VFA control agent. A composition for carrying out the method is also disclosed.