EP0712452A1 - Procede perfectionne de desencrage par agglomeration de l'encre - Google Patents

Procede perfectionne de desencrage par agglomeration de l'encre

Info

Publication number
EP0712452A1
EP0712452A1 EP94924565A EP94924565A EP0712452A1 EP 0712452 A1 EP0712452 A1 EP 0712452A1 EP 94924565 A EP94924565 A EP 94924565A EP 94924565 A EP94924565 A EP 94924565A EP 0712452 A1 EP0712452 A1 EP 0712452A1
Authority
EP
European Patent Office
Prior art keywords
ink
pulp medium
medium
pulp
deinking
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94924565A
Other languages
German (de)
English (en)
Other versions
EP0712452A4 (fr
Inventor
Narendra R. Srivasta
Larry D. Markham
Richard R. Wesolowski
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Paper Co
Original Assignee
International Paper Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Paper Co filed Critical International Paper Co
Publication of EP0712452A1 publication Critical patent/EP0712452A1/fr
Publication of EP0712452A4 publication Critical patent/EP0712452A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
    • D21C5/02—Working-up waste paper
    • D21C5/025—De-inking
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/64—Paper recycling

Definitions

  • This invention generally relates to an improved agglomeration process to deink printed paper. More particularly, it concerns a process which provides more effective agglomeration of ink particles by separating the defibering and agglomeration steps which are subject to different chemical and physical requirements. Agglomerated ink particles are removed by size and density separation procedures to produce an ink free pulp medium used to make recycled paper and board products.
  • U.S. Patent No. 4,561,933 to Wood discloses a process for deinking xerographically printed wastepaper. Repulped printed wastepaper is treated with a deinking agent consisting of a mixture of alkanols and alcohol ethoxylates to produce a suspension of ink particles. The suspended ink particles are separated from the resulting pulp-medium by washing and flotation process steps.
  • the deinking chemical and process in Wood is limited to deinking only xerographic waste and utilizes multiple process steps to separate the ink.
  • Agglomeration chemicals consisting of polymeric or surfactant systems are employed to aid in the ink agglomeration process.
  • deinking paper through agglomeration processes the waste paper is repulped and then deinked through chemical treatment to provide a slurry of pulp and ink agglomerates.
  • the ink agglomerates are removed from the pulp by sedimentation and separation procedures.
  • a more specific object of the invention is to provide a deinking process and related apparatus which utilizes a two-component deinking chemical, including alkanol and nonionic surfactant based systems, for the agglomeration of all types of inks, both impact and nonimpact, from wood containing and wood free grades of paper, in which the components are added separately during the deinking process to improve agglomeration of ink particles.
  • a two-component deinking chemical including alkanol and nonionic surfactant based systems
  • Another object of the invention is to provide a low cost agglomeration deinking process that effectively and efficiently removes ink without using a high concentration of expensive agglomeration chemicals.
  • a further specific object of the invention is to provide an agglomeration deinking method which is less complex than the prior art ink removal procedures.
  • Another object of the invention is to provide a recycled paper product having a high level of cleanliness made by the agglomeration deinking method of the invention from printed wastepaper.
  • a further specific object of the invention is to increase the pulp brightness by recirculating the substantially ink free pulp medium and reject streams to cause additional agglomeration of ink particles, wherein removal of the reagglomerated ink particles produces a cleaner pulp medium.
  • agglomeration process for deinking printed paper by separating the defibering and agglomeration steps which are subject to different chemical and physical requirements. Size and density separation procedures are employed to remove agglomerated ink particles and produce an ink free pulp medium for use in the fabrication of recycled paper and board products.
  • the general deinking process comprises the steps of defibering the printed paper to produce a pulp medium and contacting with an aqueous medium containing an agglomeration deinking chemical. The presence of the deinking chemical causes agglomeration of ink particles to produce an ink pulp medium.
  • the defibering and agglomeration are done separately in a defibering device and mixing vessel, respectively.
  • the ink pulp medium is passed through a pressure screen and/or a centrifugal cleaner to remove ink particles and to produce a substantially ink free pulp medium.
  • the substantially ink free pulp medium is thickened and then made into a recycled paper product through conventional paper-making processes.
  • the substantially ink free pulp medium is recirculated to the mixing vessel to cause additional agglomeration of ink particles.
  • the agglomerated ink particles are removed to produce a cleaner pulp medium.
  • reject streams from the production of the substantially ink free pulp medium are recirculated to the mixing vessel to again cause additional agglomeration of ink particles.
  • the agglomerated ink particles are removed to increase pulp medium yield and ink removal efficiency.
  • the pulp medium may be subjected to screening and cleaning procedures to remove contaminants, such as staples, glass, paper clips, plastic and stickies prior to agglomeration in the mixing vessel.
  • the deinking chemicals used in the invention are generally a blend of chemicals having at least two different component functionalities.
  • the first component referred to as chemical A
  • the second component referred to as chemical B
  • chemical B is a coalescing/liquid bridging agent.
  • the process of the invention utilizes a single deinking agent containing the combined components and functionalities of deinking chemicals A and B. Alternatively, deinking chemical A and deinking chemical B are added as separate components at different points in the invention process.
  • the net effect is to split up the chemical actions of the deinking agent to permit higher concentrations of active agents at the unit operations where they are most effective.
  • Deinking chemical A is typically a nonionic surfactant of the ethoxylate type
  • deinking chemical B is an alkanol which functions as a coalescing and/or liquid bridging agent.
  • Process and reaction conditions are controlled in the defibering device and mixing vessel so that effective agglomeration of the ink particles is accomplished. Concentrations of the deinking chemical, as well as the pH and temperature of the aqueous medium are adjusted to yield maximum agglomeration of the ink particles. Coarse and fine ink particles are removed from the ink pulp medium by size and density separation procedures. The resulting ink free pulp medium has a speck removal and brightness level sufficient to produce high-grade recycled paper.
  • Preferred applications of the method of the invention include use in deinking printed paper to produce high-grade recycled printing and writing paper, or other products such as tissue and towelling, bag grades or board products.
  • the deinking method of the invention provides agglomeration processes that are less complex and expensive and more efficient than known agglomeration processes.
  • the invention also provides an apparatus for deinking printed paper utilizing a repulping means, an agglomeration means, a separation means for coarse ink and fine ink and a production means to produce recycled paper.
  • FIG. 1A is a diagrammatic view of the general process steps of the invention for deinking of printed paper
  • FIG. IB is a diagrammatic view of another embodiment of the general process steps of the invention for deinking of printed paper;
  • FIG. 2 is a schematic view of an apparatus for deinking of printed paper in accordance with the process of the present invention.
  • FIG. 3 is a schematic view of an apparatus for deinking of printed paper in accordance with another embodiment of the process of the invention.
  • the present application is specifically directed to a deinking process which provides more effective agglomeration of ink particles by separating the defibering and agglomeration steps.
  • Effective agglomeration of ink particles is achieved by splitting the defibering and agglomeration actions which are subject to different chemical and physical requirements.
  • Agglomerated ink particles are removed by size and density separation procedures to produce an ink free pulp medium used to make recycled paper and board products.
  • Copending U.S. Patent Application No. 07/771,370 filed October 3, 1991 discloses use of an agglomeration tower to separate the repulping and agglomeration steps.
  • Specific deinking chemicals used in the present invention are disclosed in copending U.S. Patent Application Nos.
  • FIG. 1A and IB are diagrammatic views of the general process steps for the deinking of printed paper.
  • Defibering of the printed paper occurs in a defibering device to produce a pulp medium 1.
  • the pulp medium is passed to a mixing vessel containing a deinking chemical 2.
  • the presence of the deinking chemical causes agglomeration of ink particles to produce an ink pulp medium.
  • the resulting ink pulp medium is passed through one or more steps of screening 3 or centrifugal cleaning 4, to remove large ink particles and contaminants and to produce a substantially ink free pulp medium 6. As shown in FIG.
  • the repulped fibers prior to reaching the mixing vessel 2 the repulped fibers may be subjected to screening and cleaning procedures 1A to remove contaminants, such as staples, glass, paper clips, plastic and stickies prior to agglomeration.
  • the substantially ink free pulp medium is recirculated to the mixing vessel 2 to cause additional agglomeration of ink particles, wherein reagglomerated ink particles are removed to produce a cleaner pulp medium.
  • reject streams from the production of the substantially ink free pulp medium are recirculated to the mixing vessel 2 to cause additional agglomeration of ink particles, wherein reagglomerated ink particles are removed to increase pulp medium yield.
  • the substantially ink free pulp medium can then be made into a recycled paper product through conventional papermaking techniques.
  • the critical aspect of the present invention process is in the separation of the defibering and agglomeration steps.
  • the mechanical and chemical actions required for the defibering and agglomeration steps are different.
  • the defibering step is carried out in a high shear device such as a hydrapulper. Other devices providing similar action can also be employed.
  • the defibering step is carried out preferably at low temperature in the range of 25 to 45"C with or without alkali to cause separation of the paper fibers. Preferably defibering is carried out for 10 to 20 minutes.
  • low shear mixing is preferred which may be achieved in a mixing vessel which is a device other than a pulper.
  • a pulper is generally used for the defibering step and not the agglomeration step.
  • Processes in which the repulping and agglomeration actions are carried out in a hydrapulper or a similar device result in the hydrapulper breaking the ink into smaller particles at the same time that the agglomeration action is forming larger particles.
  • agglomeration will proceed without any particle breakdown thereby producing larger agglomerates which are easier to remove from the pulp. This increases the utilization of pulper capacity, which can be a serious limitation in some commercial operations.
  • the invention process therefore provides for increased production through better pulper utilization and increased yield of clean pulp.
  • the mixing vessel can also be used for bleaching the pulp since temperature and pulp consistency conditions are suitable. Multiple stage bleaching could be accomplished in the vessel because of its design for continuous gentle agitation.
  • the pulp medium is passed to the mixing vessel where the deinking chemicals are added.
  • Agglomeration deinking chemicals used in the invention are a blend of chemicals having at least two different component functionalities.
  • the first component referred to as chemical A
  • the second component referred to as chemical B
  • chemical A acts to remove ink from fiber, lower the glass transition temperature of polymeric inks and to wet the ink particles.
  • the second component referred to as chemical B
  • the process of the invention utilizes a single deinking agent containing the combined components and functionalities of deinking chemicals A and B.
  • deinking chemical A and deinking chemical B are added as separate components at different points in the invention process. The net effect is to split up the chemical actions of the deinking agent to permit higher concentrations of active agents at the unit operations where they are most effective.
  • Chemical A which removes ink from the paper fiber and reduces the glass transition temperature of inks, is preferably an ethoxylated nonionic surfactant, but any other nonionic surfactant may be used.
  • Chemical B is an alkanol, preferably a mixture of C 5 to C 20 alkanols, but any liquid bridging or coalescing agent for ink may be used.
  • deinking agent as known in the art can be used in the process of the invention.
  • Many types of deinking agents which may be used have been proposed in copending U.S. Patent Application Nos. 08/093,443 and 07/984,784. These applications disclose deinking compositions including a mixture of C ⁇ to C 20 alkanols and nonionic surfactants. Alkanols with a carbon number range from 8 to 16 having a straight chain or a slightly branched structure are most preferred.
  • secondary or tertiary alcohols or any chemical agent capable of strong hydrogen bonding and forming liquid bridges between ink particles causing them to agglomerate are used in the invention.
  • nonionic surfactants which may be used in the invention including polyakyleneoxy ether, polyoxyalkylether, polyoxyethylenephenol ether, oxyethylene-oxypropylene block copolymer, polyoxyethylenealkylamine, sorbitan fatty acid ester, polyoxyethylenesorbitan fatty acid ester, polyethylene glycol esters and diesters and any other nonionic surface active agents with wetting power to reduce the surface tension of water molecules.
  • Particularly preferred nonionic surfactants are of the polyakyleneoxy ether type or ethoxylate derivatives of the C 5 to C 20 alkanols, having an ethoxylate content sufficient to provide detergency or wetting.
  • the ethoxy (EO) group to alcohol, mole/mole average ratio of the deinking compositions range from 0.001 to 12.
  • Hydrophobicity of the compositions as measured hydrophobic-hydrophilic balance (HLB) values range from 0.5 to 12.
  • the cloud point of the compositions are less than 200 "F and hydroxyl values (expressed as eq./lOO g) are greater than 0.0001.
  • deinking compositions have HLB values ranging from 0.5 to 6, ethoxy group to alcohol, mole/mole avg. ratio ranging from 0.1 to 5, cloud points in the range of 5 to 100 "F and a hydroxyl value between 0.1 and 1.
  • deinking agents which may be used in the invention include a mixture of one or more C 5 - C 20 alkanols and alcohol ethoxylates in the ratio of 4:1 to 1:1.5 of alkanols to alcohol ethoxylates. Specifically, where for every 10 parts by weight of alkanol and alcohol ethoxylates there are between 3.0 and 8.0 parts alkanol and between 2.0 and 7.0 parts alcohol ethoxylates.
  • FIGS. 2 and 3 illustrate embodiments of the invention process.
  • the net effect of the invention process is to separate the defibering and agglomeration actions.
  • a single deinking agent containing the combined components and functionalities of deinking chemicals A and B are added to the mixing vessel, 14.
  • the deinking chemical components A and B are split and added at different points in the invention process.
  • Deinking chemical A is added to the pulper 12, and deinking chemical B is added to the mixing vessel 14. This latter embodiment splits the chemical actions of the deinking agent to permit higher concentrations of active agents at the unit operations where they are most effective.
  • FIG. 2 is a schematic view of an apparatus, generally designated 10, for practicing the deinking process of the invention.
  • the process of the invention entails defibering the wastepaper, causing agglomeration of the ink particles with the addition of a deinking chemical in aqueous medium, and removal of the agglomerated ink by screening and forward cleaning.
  • the printed paper is repulped in an aqueous medium at hydrapulper 12 to produce a pulp medium.
  • the defibering of the printed paper is generally at temperatures in the range of 25 to 45° and carried out for a time long enough to cause separation of the paper fibers.
  • the aqueous medium in the mixing vessel is maintained at a pH in the range of 7 - 11.5 and at temperatures in the range of 40 - 90 ⁇ C.
  • Any type of printed paper may be used in this invention including computer printout paper, writing paper, fine paper, coated and uncoated magazine paper, newsprint and packaging board. This list is merely representative of the different types of printed paper and is not considered to be inclusive of all the possible types of printed paper which may be used in the invention. TABLE II TYPES OF PRINTED PAPER
  • the sorted printed waste paper is slushed at consistency range between 3 and 30%, in the hydrapulper.
  • the repulping is preferably done in an alkali aqueous medium, with sodium hydroxide added to speed the repulping and to aid in the separation of ink particles from the pulp fibers.
  • Ambient temperature is preferred when using highly contaminated waste in the hydrapulper since at higher temperatures contaminants, such as stickies, would break down making them difficult to remove.
  • the pulp medium may optionally be passed to a detrashing unit (not shown) , which removes large contaminants such as large pieces of plastic or metal.
  • the pulp medium is then pumped to a mixing vessel 14 where the addition of the deinking chemical causes agglomeration of ink particles to produce an ink pulp medium.
  • the pulp medium is passed to the mixing vessel for at least 10 minutes, preferably from 20 to 60 minutes, and maintained at a pH in the range of 7 - 11.5 at temperatures in the range of 40 to 90°C.
  • the deinking chemical is present preferably at a dosage range between 0.1 to 3% by weight, calculated on the dry weight of the pulp used.
  • the ink pulp medium is passed through dump chest 16 and a liquid cyclone 18, for removal of heavy contaminants, such as paperclips, staples and glass. After removal of the heavy debris the ink pulp medium is passed through a series of slotted screens 20, 22.
  • the ink pulp medium at consistencies ranging from 0.5 to 6.0%, and temperatures from 25-55°C, is passed through slotted pressurized screens to remove coarse contaminants and large ink particles.
  • the coarse screens 20, typically have hole sizes in the range of 0.040" to 0.062", and the fine screens 22, have slots of width between 0.006" to 0.012".
  • secondary and tertiary screening stages are often used for both coarse and fine screening to reduce the loss of good fiber from the system.
  • the slotted screens 22 remove a large percentage of the stickies from the system, including adhesives from self-stick envelopes and labels. Removal of the stickies is critical during the deinking process. High efficiency stickies removal by the fine screens is achieved in the system by maintaining the screening temperature at close to ambient " temperature, so that the stickies do not become softened and more deformable for extrusion through the slots into the pulp accepts stream.
  • the ink pulp medium is diluted to 1% consistency or less at dilution tank 24, for pumping through a set of forward cleaners (centrifugal cleaners) 26, 28, for removal of the agglomerated ink particles denser than water to produce a substantially ink free pulp medium.
  • forward cleaners centrifugal cleaners
  • the substantially ink free pulp medium may be recirculated to the mixing vessel 14.
  • the presence of the deinking agent B causes additional agglomeration of ink particles which are subsequently removed by screening and cleaning procedures.
  • reject streams from the production of the substantially ink free pulp medium may be recirculated to the mixing vessel 14 where the presence of the deinking agent causes additional agglomeration of ink particles.
  • the reagglomerated ink particles are removed by screening and cleaning procedures.
  • the further steps of recirculating the substantially ink free pulp medium and reject streams result in increased pulp medium yield and produce a cleaner pulp medium.
  • the substantially ink free pulp is thickened 30, and used to make recycled paper by conventional papermaking techniques.
  • FIG. 3 is a modification of the process of the invention in which the deinking chemical is separated into chemical components A and B which are added at different points in the invention process.
  • This embodiment splits the chemical actions of the deinking agent to permit higher concentrations of active agents at the unit operations where they are most effective.
  • the printed paper is defibered in a hydrapulper 12 and passed to a mixing vessel 14, where deinking chemical A is added.
  • Deinking chemical A acts to remove ink from the pulp fiber, lower the glass transition temperature of polymeric inks and wet the ink particles.
  • deinking chemical A is an ethoxylated nonionic surfactant, though many others may be used as previously indicated.
  • Contaminant removal is achieved by passing the pulp medium through dump chest 16, liquid cyclone 18, slotted screens 20, 22. After passing through dilution tank 24 and forward cleaning stations 26, 28 the reject streams are passed to chest 34 where deinking chemical B is added.
  • Deinking chemical B is a coagulating/liquid bridging agent and is preferably an alkanol.
  • the presence of deinking chemicals A and B causes agglomeration of ink particles to produce and ink pulp medium.
  • This ink pulp medium is recirculated to the dump chest 14, and passed through screening and centrifugal cleaners to remove ink particles from the ink pulp medium to produce a substantially ink free pulp medium.
  • chemical A at a dosage of 0.2 to 0.4% by weight of pulp is added in the mixing vessel 14.
  • This addition helps reduce the pulping time to that sufficient for defibering alone, 10 minutes instead of the normal 30 minutes, and allows a lower temperature to be used in the pulper. This change would also provide for higher throughput in the pulper.
  • Chemical B is added at a dosage of 0.2 to 0.5% by weight of pulp. This leads to a 50% or more cost savings in chemical costs and is more effective than conventional processes.
  • Another alternative embodiment is the replacement of the first set of forward cleaners 26 with pressure screens having fine slots, between 0.006" to 0.012" slot width, for removal of the large agglomerated ink particles.
  • additional sets of forward cleaners 26, 28 can be added in a 2°, 3°, or 4° arrangement for further improvement in the cleanliness and yield of the pulp.
  • Example I A comparison of conventional agglomeration deinking methods and the method of the invention is shown in Example I below.
  • printed wastepaper was defibered and contacted with a deinking chemical in the same vessel, a hydrapulper, to produce an ink pulp medium.
  • the printed paper was defibered in the hydrapulper and then passed to a mixing vessel where a deinking agent was added.
  • the deinking agent used in Example I is a mixture of one or more C 5 - C 20 alkanols and nonionic surfactants.
  • Example II illustrates the process of the invention in which the deinking chemical is separated into chemical components A and B which are added at different points in during the deinking process. This embodiment splits the chemical actions of the deinking agent to permit higher concentrations of active agents at the unit operations where they are most effective.
  • AlfolTM1012 is a blend of C 10 . 12 alkanols and AlfonicTM1216- 22 is C 12 . 16 alcohol ethoxylates, both chemicals are from Vista Chemicals, Houston, Texas.
  • Sample B was repulped with the deinking agent for 30 minutes at 70°C. Brightness and dirt count measurements were taken and listed below in Table IV.
  • sample C the same deinking chemical and component proportions were used, however, the components were added during separate process steps.
  • the brightness data in Table IV shows an increase in brightness of 2.7% GE when the chemicals are added separately (sample C) . This is due to improved agglomeration, i.e. fewer small ink specks.
  • the average particle size at the end of the conventional treatment is 0.059 sq.mm.
  • we split the components and add them as necessary then we increase the average particle size to 0.064 sq. mm (sample C) . This demonstrates that split chemical addition provides for improved agglomeration.
  • the method of this invention for deinking printed paper is less complex than conventional deinking processes involving washing and flotation procedures and known agglomeration procedures.
  • advantages of the process of this invention include the increased utilization of pulper capacity which can be a serious limitation in commercial operations. Through better pulp and deinking chemical utilization more effective agglomeration occurs leading to better ink removal and increased yield of brighter, cleaner pulp. The higher effectiveness of the agglomeration step leads to lesser equipment requirements and decreased capital costs.
  • the invention process also adds deinking chemicals at points where they would be most efficient and could lead to a lower dosage of chemicals used. Numerous modifications are possible in light of the above disclosure such as application of alternative agglomeration deinking chemicals chosen according to the wastepaper treated.
  • alternative process parameters may be employed in the invention, which include using the deinking agent with no pH adjustment to the wastepaper; using the deinking agent in an alkali pH range; or using the deinking agent in the presence of other chemicals suitably employed in a deinking and/or papermaking process such as bleaching agents, defoamers, sizing agents, brighteners, water quality processing agents among others.

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Abstract

Le désencrage du papier imprimé s'effectue par défibrage des vieux papiers imprimés (1) pour donner un milieu cellulosique et par mise en contact de ce milieu avec un milieu aqueux comprenant un produit chimique de désencrage (2), dans lequel la présence de ce produit chimique provoque l'agglomération des particules d'encre pour donner un milieu de cellulose et d'encre. Les particules d'encre agglomérées sont éliminées du milieu de cellulose et d'encre au moyen de procédés de séparation par taille (3) et densité (4) afin de donner un milieu cellulosique pratiquement dépourvu d'encre. La présente invention décrit des procédés perfectionnés de désencrage permettant une très bonne élimination de l'encre du papier imprimé par agglomération plus efficace des particules d'encre grâce à des actions séparées de défibrage et d'agglomération dont les exigences physico-chimiques sont différentes.
EP94924565A 1993-08-02 1994-08-02 Procede perfectionne de desencrage par agglomeration de l'encre Withdrawn EP0712452A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US10088693A 1993-08-02 1993-08-02
US100886 1993-08-02
PCT/US1994/008774 WO1995004187A1 (fr) 1993-08-02 1994-08-02 Procede perfectionne de desencrage par agglomeration de l'encre

Publications (2)

Publication Number Publication Date
EP0712452A1 true EP0712452A1 (fr) 1996-05-22
EP0712452A4 EP0712452A4 (fr) 1999-04-21

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EP94924565A Withdrawn EP0712452A4 (fr) 1993-08-02 1994-08-02 Procede perfectionne de desencrage par agglomeration de l'encre

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EP (1) EP0712452A4 (fr)
AU (1) AU7479994A (fr)
CA (1) CA2168578A1 (fr)
WO (1) WO1995004187A1 (fr)

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Publication number Priority date Publication date Assignee Title
CN113060944A (zh) * 2021-03-25 2021-07-02 肥西常福中空玻璃厂 一种玻璃脱墨设备

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0510954A1 (fr) * 1991-04-25 1992-10-28 Betz Europe, Inc. Procédé et composition pour désencrer du vieux papier imprimé électrostatiquement avec un toner
WO1993007331A1 (fr) * 1991-10-03 1993-04-15 International Paper Company Procede ameliore de desencrage par agglomeration d'encre

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4561933A (en) * 1983-10-17 1985-12-31 Shell Oil Company Xerographics deinking
US4820379A (en) * 1986-10-16 1989-04-11 Ppg Industries, Inc. Method for deinking wastepaper with a halogenated polyethylene oxide and a polymeric material
US4895622A (en) * 1988-11-09 1990-01-23 Betz Laboratories, Inc. Press felt conditioner for neutral and alkaline papermaking systems

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0510954A1 (fr) * 1991-04-25 1992-10-28 Betz Europe, Inc. Procédé et composition pour désencrer du vieux papier imprimé électrostatiquement avec un toner
WO1993007331A1 (fr) * 1991-10-03 1993-04-15 International Paper Company Procede ameliore de desencrage par agglomeration d'encre

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9504187A1 *

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AU7479994A (en) 1995-02-28
EP0712452A4 (fr) 1999-04-21
WO1995004187A1 (fr) 1995-02-09
CA2168578A1 (fr) 1995-02-09

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