Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/261—Alcohols; Phenols
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/50—Solvents
  • C11D7/5004—Organic solvents
  • C11D7/5013—Organic solvents containing nitrogen
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/50—Solvents
  • C11D7/5004—Organic solvents
  • C11D7/5022—Organic solvents containing oxygen
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/263—Ethers
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/264—Aldehydes; Ketones; Acetals or ketals
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/267—Heterocyclic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/32—Organic compounds containing nitrogen
  • C11D7/3281—Heterocyclic compounds

Definitions

• This invention relates to providing clean wires and felts for paper production and, more particularly, to chemical treatment for controlling deposits on papermill wire and felt.
• the manufacture of paper typically involves the processing of a carefully prepared aqueous fiber suspension to produce a highly uniform dry paper sheet.
• Three steps included in the typical process are sheet forming, where the suspension is directed over a porous mesh or "wire” upon which fibers are deposited while liquid filters through the wire; sheet pressing, where the formed sheet is passed through presses covered with porous "felt” to extract retained water from the sheet, to improve the sheet's uniformity, and to impart surface quality to sheet; and paper drying, where residual water is evaporated from the sheet.
• the sheet may then be further processed into the finished paper product.
• the quality of the aqueous fiber suspension used to produce sheet is dependent upon many factors, including the wood and water used as raw materials, the composition of any recycled material added to the process, and the additives used during preparation of the suspension.
• a variety of dissolved or suspended materials can be introduced into the manufacturing process, including both inorganic materials such as salts and silts, and materials which are organic in nature such as resins or "pitch" from the wood, and inks, latex, and adhesives from recycled paper products.
• a build up of "soil” containing inorganic and/or organic materials on wires and felts during the manufacturing process is recognized as a troublesome obstacle to efficient papermaking.
• a cleaning liquid typically water
• the showers can be assisted by mechanical surface cleaning.
• Use of water showers, with or without mechanical assistance, has not proved entirely satisfactory in preventing a build-up of either organic or inorganic metals from the wires, and additional materials have been used to provide cleaning liquids which are more effective.
• Inorganic materials have best been removed using water-based formulations containing either acids or alkalis together with other chemicals such as surfactants.
• the organic deposits have normally been removed using organic solvents including some formulations containing aromatic compounds with low flash points or chlorinated hydrocarbons.
• Papermill felts also commonly circulate continuously in belt-like fashion between a sheet contact stage and a return stage.
• a clean felt is essential for effective paper manufacture since this allows efficient removal of water from the paper sheet.
• the cleaning procedure should remove both organic and inorganic soils of both a general and localised nature, maintain felt porosity, and condition the fabric nap without chemcal or physical attack on the substrate.
• Mechanical removal typically by blade contact, has been used to remove debris from the felt surface.
• cleaning liquids are also utilized to remove troublesome build-up of organic and inorganic deposits.
• the fabric composition and conformation of many papermill felts makes them susceptible to chemical degradation. The chemicals should be easily removed by rinsing. Both continuous and shock cleaning is used in most papermills.
• the chemicals used include organic solvents, often chlorinated hydrocarbons. Acid and alkali based systems are also used, but at lower concentrations than used in wire cleaning. High concentrations of alkali metal hydroxides are often unsuitable for felt cleaning as they "attack" the fabric material.
• An object of this invention is to provide a stable papermill wire and felt cleaner which can effectively remove soil materials which have deposited on wire and felt.
• a further object of this invention is to provide a wire and felt cleaning product which can be used to remove both organic and inorganic deposits.
• Another object of this invention is to provide papermill felt cleaning which is relatively non-aggressive toward felt fabric.
• Still another object of this invention is to provide papermill wire and felt cleaning which has improved effectiveness.
• Yet another object of this invention is to provide papermill wire and felt cleaning in a manner which is environmentally acceptable.
• the present invention is directed to certain combinations of organic cleaning components with alkali materials which provide surprisingly effective removal of both organic and inorganic deposits from papermill wires and felts.
• the alkali materials of this invention can be any of the alkali materials suitable for use in aqueous solution to remove inorganic deposits from papermill wires and felts. These materials are believed to function by hydrolysing and solubilizing the inorganic deposits and include alkali metalhydroxides (most notably sodium hydroxide and potassium hydroxide) and alkali metal metasilicates, especially sodium metasilicate.
• alkali metal hydroxides are preferred, with sodium hydroxide being the most preferred from an economic and effectiveness standpoint.
• concentrations of these alkali materials needed to rapidly remove inorganic deposits can be detrimental to certain materials on which the deposits adhere, and the effectiveness of alkali when used alone is limited, particularly where organic deposits are present.
• N-methyl-2-pyrrolidone or structurally related compounds, having the general formula: wherein each R1 is independently selected from the group consisting of hydrogen, methyl or ethyl and Z is methyl or ethyl. These compounds will be referred to herein as "Formula A" compounds. Most preferred is N-methyl-2-pyrrolidone itself (i.e., each R1 is hydrogen). N-methyl-2- pyrrolidone is a known component of various cleaning formulations for ovens, cookware, ceramic material, and has also been used in paint remover compositions. It has been suggested for use as a papermill wire and felt cleaner, and its relatively low toxicity makes it an acceptable material from an environmental standpoint.
• the organic cleaning component of this invention may advantageously comprise ⁇ -butyrolactone or structurally related compounds having the general structural formula: wherein R2 is hydrogen or methyl and R1 is as defined above. These compounds will be referred to herein as "Formula B" compounds.
• R2 is hydrogen (i.e., a preferred organic cleaning component is ⁇ -butyrolactone).
• ⁇ -butyrolactone has been used as a solvent for resins, as a paint remover, and the like. Its effectiveness when used alone as a wire and felt cleaner is, however, limited.
• the alkali materials described above can be combined with an organic cleaning component selected from the group consisting of Formula A compounds and Formula B compounds to provide stable and effective wire and felt cleaners.
• the preferred organic cleaning compounds of this invention are selected from the group consisting of N-methyl-2-pyrrolidone and ⁇ -butyrolactone. Not only can organic and inorganic deposits be removed simultaneously, but their removal is accomplished at surprisingly low dosages. Thus, a particularly advantageous process is also provided for producing clean papermill wires and felts from soiled wires and felts.
• Suitable organic cosolvents must be capable of providing stable aqueous solutions of Formula A compounds and/or Formula B compounds at high alkalinities. That is, the organic cosolvent must provide increased effectiveness at levels where there is no phase separation into generally organic and aqueous phases.
• the organic cosolvents which can be used in accordance with this invention to provide the improved effectiveness without causing phase separation include glycol ethers, isopropanol, and acetone.
• many of the cosolvents capable of providing product stability also have properties which are environmentally undesireable (eg. relatively low flash points), and thus should be avoided in many circumstances where exposure or release are of concern.
• Preferred organic cosolvents thus include glycol ethers having the general formula: C n H 2n+1 O [CH2CH2CH2O] m [CH2CH2O] k H in which n is an integer from 1 to 4, m is an integer from zero to two, k is an integer from zero to two, and m plus k is at least one.
• a particularly preferred glycol ether is 2-butoxyethanol (i.e., n is 4, m is zero, and k is 1).
• the weight ratio of applied components should be regulated so that a single phase cleaning system is provided during cleaning, and the surprisingly effective treatment of this invention is attained.
• the weight ratio of alkali to organic cosolvent is kept between about 1:80 and about 14:1; and where a Formula A compound is the organic cleaning component, its ratio to the organic cosolvent is kept between about 100:1 and about 1:40.
• a Formula B compound is the organic cleaning component rather than a Formula A compound, its ratio to the organic cosolvent is generally kept between about 40:1 and about 1:40.
• the amount of water present should be at least equal to the amount of organic cosolvent. It is generally more convenient, however, to provide the components together in the form of a composition.
• Effective compositions formulated in accordance with this invention include those containing between about 0.5 and about 50 weight percent of Formula A compound, preferably N-methyl-2-pyrrolidone, between about 0.5 and about 20 weight percent organic cosolvent, between about 0.25 and about 7.0 weight percent alkali material, and between about 30.0 and about 98.8 weight percent water.
• Other effective compositions advantageously formulated in accordance with this invention contain between about 0.5 and about 20 weight percent Formula B compound, preferably ⁇ -butyrolactone, between about 0.5 and about 20 weight percent organic cosolvent, between about 0.25 and about 7.0 weight percent alkali material, and between about 60.0 and about 98.8 percent water.
• the preferred ranges are from about 5 to about 12 weight percent of an organic cleaning component selected from the group consisting of Formula A compounds and Formula B compounds; from about 2.5 to about 12.5 weight percent of organic cosolvent; from about 2.0 to about 5.5 weight percent of alkali; and from about 60.0 to about 88.0 weight percent water; particularly where the organic cleaning component is selected from the group consisting of N-methyl-2-pyrrolidone and ⁇ -butyrolactone.
• the most preferred ranges are from about 7.5 to about 10.5 weight percent of said organic cleaning component; from about 7.5 to about 10.5 weight percent of organic cosolvent; from about 2.5 to about 5.0 weight percent of alkali; and from about 67.0 to about 82.5 weight percent water; particularly where 2-butoxyethanol and sodium hydroxide are used as the organic cosolvent and alkali material, respectively and the organic cleaning component is selected from the group consisting of N-methyl-2-pyrrolidone and ⁇ -butyrolactone.
• Suitable corrosion inhibitors for use in this manner include alkanolamine salts of aryl sulphonamide carboxylic acids, such as the product Hostacor KS1-X available commercially from Hoechst.
• Preferred surfactants for use in this manner include n-alkyl ethoxy dimethylamine oxides where the alkyl has between about 12 and about 18 carbons, such as the product Empigen OY (25% active) available commercially from Albright and Wilson; and lauryl/myristyl. dimethylamine oxides, such as the product Empigen OB (30% active) commercially available from Albright and Wilson.
• the treatment dosage depends on the nature of the soil material, and whether cleaning is continuous or periodic.
• the compositions may be employed at full strength (100%), for example by spraying the composition directly onto the felt and/or wires, especially where shock cleaning for rapid removal of build up deposits is necessary.
• the compositions may be advantageously diluted prior to treatment with water or other suitable liquid, such as the aqueous liquid of the papermaking process itself.
• water or other suitable liquid such as the aqueous liquid of the papermaking process itself.
• Continuous cleaning as used herein means that the wire or felt is routinely treated at least once during the cycle between its sheet contact stage and its return stage.
• This routine treatment can advantageously occur during the period when the wire and felt is not in contact with sheet material (i.e. the return stage).
• the deposited material is then typically washed away with the draining treatment liquid.
• addition of the composition to the papermill process water itself can also be practiced in accordance with this invention; and that continuous cleaning during the sheet contact portion can be effective. Cleaning during sheet contact provides inhibition of soil build-up and therefore functions in a preventive capacity rather than merely in a removal capacity. Continuous cleaning during sheet contact is especially appropriate for wire cleaning where the inorganic and organic materials can be washed through the wire with the filtered process water, and thus can be transported away from both the wire and the sheet without affecting the sheet-forming process.
• the concentration of organic cleaning component in the liquid contacting the wire or felt should be at least about 5 ppm, and the free alkalinity of the liquid contacting the wire or felt should be at least about 2 ppm (expressed as the amount of NaOH equivalent to the free hydroxyl ion present).
• continuous treatment in accordance with this invention will provide between about 50 ppm and about 500 ppm of organic cleaning component, and between about 20 ppm and about 200 ppm free alkalinity (as NaOH).
• a synthetic polyester-polyamide papermill wire soiled with both inorganic and organic material was soaked in substantially pure N-methyl-2-pyrrolidone for about 30 minutes. The papermill wire was then removed and the amount of soil removed was simply measured by determining the difference in wire weight due to treatment.
• a second run was made using substantially pure 2-butoxyethanol instead of N-methyl-2-pyrrolidone, and a third run was made using a 50 percent solution of sodium hydroxide in water as the sole treatment agent.
• a fourth run was made using a composition containing 4.3 weight percent sodium hydroxide, 8.8 weight percent 2-butoxyethanol, 5.3 weight percent (active) corrosion inhibitor and surfactants (added as Hostacor KS1-X, Empigen OY, and Empigen OB), and the remainder water; and a fifth run was made using a composition containing the same weight percentages of sodium hydroxide, 2-butoxyethanol, corrosion inhibitor, and surfactants as the fourth run, but also containing 8.8 percent of N-methyl-2-pyrrolidone and the remainder water.
• Table I The results of these five runs are shown in Table I below.

Priority Applications (7)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8197791

Family Applications (1)

Country Status (7)

Cited By (4)

Citations (3)

• 1987
  • 1987-02-16 EP EP87301326A patent/EP0279089A1/fr not_active Ceased
• 1988
  • 1988-02-12 BR BR8800617A patent/BR8800617A/pt unknown
  • 1988-02-13 MY MYPI88000149A patent/MY103204A/en unknown
  • 1988-02-15 FI FI880705A patent/FI880705A/fi not_active Application Discontinuation
  • 1988-02-15 CA CA000558892A patent/CA1319078C/fr not_active Expired - Fee Related
  • 1988-02-15 AU AU11714/88A patent/AU600091B2/en not_active Ceased
  • 1988-02-15 JP JP63031034A patent/JPS63259000A/ja active Pending

Patent Citations (3)

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