# US 2009/0260767 A1 · Use of hydrophobic dyes to monitor hydrophobic contaminants in a papermaking process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260767 A1 - Document ID: US20090260767A1 - Status: Published application - Kind: A1 - Application number: 12/405,807 - Filed: 2009-03-17 - Published: 2009-10-22 - Earliest claimed: 2003-04-14 - Assignees: Every Penny Counts, Inc. - Inventors: Alessandra Gerli; Laura M. Sherman; Michael J. Murcia - Web page: https://patentgrep.com/patent/US20090260767A1 ## CPC - G01N 33/343: {Paper pulp} - G01N 2021/6439: {with indicators, stains, dyes, tags, labels, marks} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A method of monitoring and controlling one or more types of hydrophobic contaminants in a papermaking process is disclosed. The methodology utilizes the measurement of hydrophobic dyes, which are capable of fluorescing and interacting with the hydrophobic contaminants. In addition, a method of determining the relative size of the hydrophobic contaminants is disclosed as well. ## Claims ### Claim 1 A method of monitoring one or more types of hydrophobic contaminants in a papermaking process comprising: a. obtaining a sample of fluid from said papermaking process; b. selecting a hydrophobic dye that is capable of interacting with said contaminants in said fluid and fluorescing in said fluid; c. adding said dye to said fluid and allowing a sufficient amount of time for said dye to interact with said contaminants in said fluid; d. measuring the fluorescence of the dye in said fluid; e. correlating the fluorescence of the dye with the concentration of said contaminants; and f. optionally controlling the amount of one or more chemicals that reduce or inactivate said contaminants which are added to said papermaking process. ### Claim 2 (depends on 1) The method of claim 1 wherein said sample is a bulk sample. ### Claim 3 (depends on 1) The method of claim 1 further comprising: measuring the turbidity of said fluid, optionally wherein said turbidity of said fluid is measured before and after the addition of said chemicals. ### Claim 4 (depends on 1) The method of claim 1, wherein said fluid is filtered or diluted or a combination thereof prior to said addition of said dye or said fluorescent measurement of said dye. ### Claim 5 (depends on 1) The method of claim 1, wherein said dye is selected from the group consisting of: 9-diethylamino-5H′-benzo[alpha]phenoxazine-5-one, 1-dimethylamino-5-sulfamoyl-naphthalene, pyrene, 1-pyrenecarbaldehyde, Reichardt's dye, 4-aminophthalimide, 4-(N,N-dimethylamino)phthalimide, bromonapthalene, 2-(dimethylamino)naphthalene, and a combination thereof. ### Claim 6 (depends on 1) The method of claim 1, wherein said dye does not include N-(n-butyl)-4-(n-butylamino)-naphthalimide. ### Claim 7 (depends on 1) The method of claim 1, wherein said dye is a solvatochromatic dye. ### Claim 8 (depends on 1) The method of claim 1 wherein said fluid is obtained from a wet end of said papermaking process. ### Claim 9 (depends on 1) The method of claim 1, wherein said contaminants are selected from the group consisting of: pitch, fiber, filler, fines, coated broke, mill broke, recycle, groundwood, thermal mechanical pulp, chemi-thermal-mechanical pulp, chemical pulp, deinked pulp, ink, adhesives, stickies, tackies, waxes, binders and dissolved and/or colloidal substances, and a combination thereof. ### Claim 10 (depends on 1) The method of claim 1, wherein said method is an on-line method and/or batch sample method. ### Claim 11 (depends on 1) The method of claim 1, wherein said fluorometric measurement is performed at a pre-set basis, intermittent basis, and/or continuous. ### Claim 12 (depends on 1) The method of claim 1, wherein said fluorometric measurement is performed with a handheld fluorometer. ### Claim 13 (depends on 1) The method of claim 1, wherein said fluid is an aqueous filtrate of a pulp slurry. ### Claim 14 A method of measuring the effectiveness of one or more chemicals that decrease the amount of one or more hydrophobic contaminants in a papermaking process: a. monitoring one or more types of contaminants in a papermaking process comprising: obtaining a sample of fluid from said papermaking process; selecting a hydrophobic dye that is capable of interacting with said contaminants in said fluid and fluorescing in said fluid; adding said dye to said fluid and allowing a sufficient amount of time for said dye to interact with said contaminants in said fluid; measuring the fluorescence of the dye in said fluid; and correlating the fluorescence of the dye with the concentration of said contaminants; b. adding one or more chemicals to said papermaking process that decrease the amount of said hydrophobic contaminants in said papermaking process; c. re-measuring the amount of contaminants in said papermaking process by performing step (a) at least one more time; and d. optionally controlling the amount of said chemicals that are added to said papermaking process. ### Claim 15 (depends on 14) The method of claim 14, wherein said chemicals are at least one of the following: a fixative; a detackifier; a dispersant; a surfactant; and a retention aid. ### Claim 16 A method of monitoring one or more hydrophobic contaminants and determining the size of said hydrophobic contaminants in a papermaking process comprising: a. obtaining a sample of fluid from said papermaking process; b. selecting a hydrophobic dye that is capable of interacting with said contaminants in said fluid and fluorescing in said fluid; c. adding said dye to said fluid and allowing a sufficient amount of time for said dye to interact with said contaminants in said fluid; d. measuring the fluorescence of the dye in said fluid; e. correlating the fluorescence of the dye with the concentration of said contaminants; f. passing the sample measured in step (d) through a medium capable of separating the sample into one or more aqueous fractions at least one time; g. measuring the fluorescence of the aqueous fractions from step (f) of said sample at least one time; h. determining the size of the hydrophobic contaminants of the aqueous fractions; i. optionally correlating the fluorescence of the dye in the aqueous fractions with the concentration of said hydrophobic contaminants in the aqueous fractions; and j. optionally controlling the amount of one or more chemicals that reduce or inactivate said contaminants which are added to said papermaking process. ### Claim 17 (depends on 16) The method of claim 16, wherein said aqueous fractions contain one or more suspended solids or one or more particles. ### Claim 18 (depends on 16) The method of claim 16, wherein the medium capable of separating is a centrifuge, a filter or a combination thereof. ### Claim 19 A method of monitoring one or more hydrophobic contaminants and determining the size of said hydrophobic contaminants in a papermaking process comprising: a. obtaining a sample of fluid from said papermaking process; b. selecting a hydrophobic dye that is capable of interacting with said contaminants in said fluid and fluorescing in said fluid; c. adding said dye to said fluid and allowing a sufficient amount of time for said dye to interact with said contaminants in said fluid; d. measuring the fluorescence of the dye in said fluid; e. correlating the fluorescence of the dye with the concentration of said contaminants; f. filtering the sample measured in step (d) at least one time through at least one filter, wherein the filter has one or more pores with a known pore size; g. measuring the fluorescence of the filtrate from step (f) of said sample at least one time; h. determining the size of the hydrophobic contaminants of the filtrate and optionally a concentrate from said filtration step; i. optionally correlating the fluorescence of the dye in the filtrate and/or reject with the concentration of said hydrophobic contaminants in the filtrate; and j. optionally controlling the amount of one or more chemicals that reduce or inactivate said contaminants which are added to said papermaking process.