US20090032206A1

US20090032206A1 - Processes used in the manufacture of paper products

Info

Publication number: US20090032206A1
Application number: US12/066,496
Authority: US
Inventors: David B. Gregory
Original assignee: JohnsonDiversey Inc
Current assignee: Diversey Inc
Priority date: 2005-09-13
Filing date: 2006-09-13
Publication date: 2009-02-05
Also published as: EP1924744A2; WO2007033091A3; JP2009508019A; WO2007033091A2; CA2622427A1

Abstract

Surfactant penetrant treating solutions and their use in the manufacture of paper products. The surfactant penetrant treating solutions include two types. The first type is an enzymatic surfactant penetrant treating solution, and the second type is a defoaming surfactant penetrant treating solution. The solutions may be used to break down recyclable paper products for use as feedstock in paper manufacturing processes. The solutions may also be used to clean the internal and external components of machinery in a paper manufacturing line.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Priority is hereby claimed to U.S. Provisional Application Nos. 60/716,704 filed Sep. 13, 2005, 60/723,674 filed Oct. 5, 2005, 60/759,492 filed Jan. 17, 2006 and 60/784,365 filed Mar. 21, 2006, the entire contents of each which are hereby incorporated by reference.

BACKGROUND

The paper manufacturing process generally reduces materials to their fiber structure and then realigns those fibers to make paper products. These fibers may be obtained from a variety of sources, including rags, seed fibers, jute, flax, grasses, animal fibers and plant fibers. More recently, fibers from recyclable products have become an important feedstock for paper manufacturing plants, whether used alone or in combination with fibers from other sources.
Despite centuries of experience in paper manufacture, the industry still faces a number of technological challenges. Current methods for breaking down recyclable paper products for use as feedstock in paper manufacture often damage the individual fibers making up the recyclable product, thus reducing the overall quality of the feedstock. In addition, manufacturing methods that use recyclable feedstock, as well as other sources of feedstock, are continually battling contamination to processing equipment as a result of impurities in feedstock and/or impurities from processes in other areas of the manufacturing line. For example, impurities resulting from latex and silicone coatings can build up on the surfaces of machine components, affecting the performance of the manufacturing equipment, as well as the quality of the recycled paper product. The result is that paper manufacturing plants require frequent downtime to clean contaminants from the machinery. The cleaning process can be expensive and result in an overall loss of productivity. Therefore, there is considerable need in the paper manufacturing industry for processes and materials that lead to more efficient paper making practices and higher quality recycled paper products.

SUMMARY

In one embodiment, the invention provides a process for recycling paper product, comprising shredding recyclable paper product, adding an enzymatic surfactant penetrant treating solution to the shredded paper product to form a mixture including a liquid and solid constituents, blending the mixture, and introducing the mixture into a wet end of a paper manufacturing process.
In another embodiment the invention provides a process for recycling paper product, comprising shredding recyclable paper product, adding a defoaming surfactant penetrant treating solution to the shredded paper product to form a mixture including a liquid and solid constituents, blending the mixture, and introducing the mixture into a wet end of a paper manufacturing process.
In a further embodiment the invention provides a process for manufacturing paper product, comprising providing pulpwood, processing the pulpwood in a standard paper manufacturing process, adding an enzymatic surfactant penetrant liquid treating solution to the processed pulpwood to create a homogeneous mixture, and introducing the mixture into a wet end of the standard paper manufacturing process.
In yet another embodiment the invention provides a method of treating the components of a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a paper web conveying system, the conveying system having a liquid applying system for application of liquid to the stock which allows liquid to drain, while the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to use in the production of the paper, the method comprising while the line is idle, adding a surfactant penetrant treating solution to the white water system to create a white water mixture and circulating the mixture through the conveying system, draining the mixture into a wastewater treatment system, and refilling the white water system with water for continued use.
In another embodiment the invention provides a method of preventing the formation of water insoluble particles of ingredients known as stickies in the white water system of a paper manufacturing line incorporating a paper stock preparation chamber for feeding paper stock to a head box for uniformly distributing the paper stock onto a paper web conveying system, having a liquid applying system for applying water to the stock which allows liquid to drain while pulp from the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained white water to aid in the production of the paper stock, the method comprising adding an enzymatic surfactant penetrant treating solution to the white water system to formulate an enzyme containing white water mixture, and recirculating the enzyme containing white water mixture to the fluid applying system while forming the web on the paper web conveying system.
In a further embodiment the invention provides a method of treating the components of a paper manufacturing line incorporating a paper stock preparation chamber for feeding paper stock to a head box for uniformly distributing the paper stock onto a paper web conveying system, having a liquid applying system for applying water to the stock which allows liquid to drain while pulp from the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained white water to aid in the production of the paper stock, the method comprising adding an defoaming surfactant penetrant treating solution to the white water system to formulate a defoaming containing white water mixture, and recirculating the defoaming containing white water mixture to the fluid applying system while forming the web on the paper web conveying system.
In yet another embodiment the invention provides a method of cleaning a portion of a paper manufacturing line that includes a head box for uniformly distributing paper stock onto a liquid-sprayed paper web conveying system that allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid, the method comprising the steps of spraying an aqueous solution to cover surfaces of a portion of the manufacturing line, the aqueous solution comprising a surfactant-penetrant-releasing agent, and rinsing the solution from the portion of the manufacturing line where the solution was sprayed.
In another embodiment the invention provides a method of cleaning a coater system of a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a liquid sprayed paper web conveying system, which allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid prior to the web reaching the coater system, the method comprising while the line is idle spraying an enzymatic surfactant penetrant treating solution to cover surfaces of the coater system, and rinsing the enzymatic surfactant penetrant treating solution from the coater system.
In a further embodiment the invention provides a method for cleaning filters in a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a liquid sprayed paper web conveying system, which allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid prior to said web reaching the coater system, the method comprising removing the filters from the paper manufacturing line, submerging the filters in a bath comprising a surfactant penetrant treating solution, removing the filters from the bath, and washing the filters with high pressure water.
In yet another embodiment the invention provides a method of making paper in a paper manufacturing line incorporating a head box for uniformly distributing paper pulp stock onto a liquid sprayed paper web conveying system which allows liquid to drain while paper pulp stock remains evenly distributed on the conveying system to form a paper web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the paper web, the method comprising adding enzymatic surfactant penetrant treating solution to the white water system.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates a paper stock preparation process according to one embodiment for a paper manufacturing line.

FIG. 2 is a schematic view of recycled paper product ingredients forming desirable, and undesirable, aggregations during the paper manufacturing process.

FIG. 3 schematically illustrates a line for manufacturing paper products from timber to end product.

FIG. 4 is a partial schematic diagram of a paper manufacturing process having an open white water system.

FIG. 5 is a partial schematic diagram of a paper manufacturing process having a closed white water system.

FIG. 6 is a schematic side elevation view of a wet end of the paper manufacturing line.

FIG. 7 is a perspective view of a head box at the wet end.

FIG. 8 is a schematic plain view of a recycling facility employing aspects of the present invention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. All percentages specified herein are by volume, unless specifically stated otherwise.
It also is understood that any numerical range recited herein includes all values from the lower value to the upper value. For example, if a concentration range is stated as 1% to 50%, it is intended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expressly enumerated in this specification. These are only examples of what is specifically intended, and all possible combinations of numerical values between and including the lowest value and the highest value enumerated are to be considered to be expressly stated in this application.
Some embodiments of the present invention relate to surfactant penetrant treating solutions (hereinafter “the treating solutions”) and their use in the manufacture of paper products, including products made from pre-consumer and/or post-consumer recyclable paper. In some embodiments, the treating solutions are environmentally friendly, non-hazardous and pH neutral. The treating solutions may be used to break down recyclable paper stock into individual fibers without degrading the structural integrity of the fibers. Aggregations of the preserved fibers and other desirable broken-down paper ingredients may be converted to new, high quality recycled paper products, regardless of whether the ingredients for the new recycled paper products contain 100 percent recyclable paper stock, or some lesser percentage thereof. Additionally, the treating solutions may be used to clean the internal and external components of the machinery in the paper manufacturing line during the active production of paper in the manufacturing process. Accordingly, the contamination of the paper making ingredients may be diminished during each paper making cycle, resulting in an increase in the tonnage of useful paper production versus recyclable paper product (broke), and the amount and frequency of downtime necessary to perform scheduled cleaning of the machinery may be minimized. The treating solution may also be used during off-line procedures to clean machinery in the paper line. During scheduled cleaning operation, such as in “boil out” procedures, the treating solutions may be used to clean the internal and external surfaces of the machinery components.
The treating solutions of the present invention include two types. The first type is an enzymatic surfactant penetrant treating solution (hereinafter “the enzymatic solution”) and the second type is a defoaming surfactant penetrant treating solution (hereinafter “the defoaming solution”).
The Enzymatic Solution
The enzymatic solution may be produced as a base aqueous mixture having substantially no anti-bacterial activity. The enzymatic solution comprises a surfactant-penetrant-releasing agent and an enzymatic agent. The surfactant-penetrant-releasing agent acts at least in part to inhibit harm to a typical biomass wastewater treatment system by preventing the biomass from being smothered by oil, grease and fat waste. Surfactant-penetrant-releasing agents comprise a surfactant-solvent, a binder-thickener, a penetrant or detergent, and water. In one embodiment, the surfactant-penetrant-releasing agent comprises about 2.3% to about 2.4% N-methyl-2-pyrrolidone (surfactant-solvent), about 0.2% to about 0.4% ethoxylated octylphenol (binder-thickener), about 1.5% to about 1.6% texanol (penetrant or detergent), and the balance water. A commercially available surfactant-penetrant-releasing agent includes Renew Systems' Aqueous ReActivator® (available from Renew Systems, Inc. in Bay, City, Mich.). In some embodiments, Renew Systems' Decontaminator™ (also available from Renew Systems, Inc. in Bay City, Mich.) may be added to the surfactant-penetrant-releasing agent to soften the chemistry of the surfactant-penetrant-releasing agent.
The enzymatic agent may contain one or more enzymes in an enzyme protectant stabilizer solution comprising water and propylene glycol (1.8-1.9%), or the like. The term enzyme is intended herein to include the well-known complex proteins produced by living cells of high molecular weight and consisting of multiple amino acids combined in a characteristic sterically-oriented structure and newer and genetically engineered enzyme compositions. A variety of basic enzyme types may include hydrolases, isomerases, ligases, lyases, oxidoreductases, and transferases. More specifically, the enzyme may come from the fermentation of a strain of Baccilus licheniformis. Examples of suitable enzymes include lipase, alpha-amylase, protease (1.8-1.9%), or the like, or a mix thereof. A commercially available enzymatic agent includes Renew Systems' Xzyme® (available from Renew Systems, Inc. in Bay City, Mich.). The percentage of enzymes by volume used in the aqueous enzymatic solution may be in the range of about 0.01% to about 3% by volume.
The enzymatic solution is made by mixing the surfactant-penetrant-releasing agent with the enzymatic agent in a volume ratio of about 8 to about 10 parts surfactant-penetrant-releasing agent to 1 part enzymatic agent. In one embodiment, the enzymatic solution is made by mixing about 9 parts surfactant-penetrant-releasing agent to 1 part enzymatic agent. In another embodiment, the enzymatic solution is made by mixing about 10 parts surfactant-penetrant-releasing agent to 1 part enzymatic agent. The resulting enzymatic solution is blended for about two hours, after which turbidity and pH measurements are taken. The pH is desirably maintained in a neutral pH range such as about 5 to about 8 on the pH scale. If the pH is not within the neutral range, a basic solution, such as an aqueous solution of sodium borate (NaBO₄), may be used to raise the pH of the enzymatic solution, and an acidic solution, such as an aqueous solution of citric acid or hydrochloric acid, may be used to reduce the pH of the enzymatic solution. A commercially available enzymatic solution includes Renew Systems' Silzyme® (available from Renew Systems, Inc. in Bay City, Mich.). The enzymatic solution may be diluted with water to provide a 0.065% to about 50% enzymatic solution before use.
The Defoaming Solution
The defoaming solution comprises the surfactant-penetrant-releasing agent from above and a defoaming (or anti-foaming) agent. The defoaming agent may comprise silicone emulsions and stabilizers and may be used to reduce the foaming due to proteins, gases, surfactants or soaps, and nitrogenous materials that may interfere with processing. Examples of defoaming agents include 2-octanol, sulfonated oils, organic phosphates, silicone fluids, methylpolysiloxane, and combinations thereof. A commercially available defoaming agent includes Foam Out® (available from Renew Systems, Inc. in Bay City, Mich.).
The defoaming solution is made by mixing the surfactant-penetrant-releasing agent with the defoaming agent in a volume ratio of at least about 98 parts surfactant-penetrant-releasing agent to about 2 parts defoaming agent. The resulting defoaming solution is blended for about two hours, after which turbidity and pH measurements are taken. The pH is desirably maintained in a neutral pH range such as about 5 to about 8 on the pH scale. If the pH is not within the neutral range, a basic solution, such as an aqueous solution of sodium borate (NaBO₄), may be used to raise the pH of the defoaming solution, and an acidic solution, such as an aqueous solution of citric acid or hydrochloric acid, may be used to reduce the pH of the defoaming solution. A commercially available defoaming solution includes Renew Systems' NuFiber™ (available from Renew Systems, Inc. in Bay City, Mich.).
Breakdown of Recyclable Paper
A paper recycling process 10 in which the treating solutions are used to break down recyclable paper is illustrated in FIG. 1. One or more types of recyclable papers may serve as recyclable paper stock for the process. In processes using the enzymatic solution, recyclable paper stock may include release paper products, such as those used as backing for stickers, newsprint, colored and/or coated box paper product, and coated corrugated cardboard. The coatings, as used on these and other types of recyclable paper products, may include silicone and latex components. In processes using the defoaming solution, recyclable paper stock may include wax-coated cartons (WCC), box paper product, and corrugated cardboard (e.g., “old” corrugated cardboard (OCC)).
The paper recycling process 10 is initiated by shredding the recyclable paper stock 12 to produce shredded recyclable paper. The recyclable paper stock may be shredded to any desired size, more particularly as small as possible. In one embodiment, the recyclable paper stock is shredded into 1″ by 1″ squares.
The shredded recyclable paper stock is then mixed with the treating solution 14 at ambient (room) temperature. The mixture may comprise about 10% to about 50% shredded paper and about 50% to about 90% treating solution. The treating solution breaks down the shredded paper product into its constituent components as shown in FIG. 2, including individual elongate wood pulp fibers 20, pigments 21, adhesives/binders 23 (generally in the enzymatic processes only), and the normal, well-known base sheet fillers 25, for example. The fibers 20 remain elongate, and substantially free from degradation due, at least in part, to the pH neutrality of the treating solution. The shredded paper stock may be wetted, such as by being blended or churned, in the treating solution for about 15 to about 20 minutes.
The mixture is then blended or mixed 16 for a predetermined amount of time to form a generally homogeneous mixture. Mixing times may be about 2 to about 10 minutes. Upon blending the mixture 16, the binding agents of the individual pieces of the shredded recyclable paper stock are broken down by the treating solution, such that the individual pieces are substantially separated into their constituent ingredients, including the generally separate fibers 20, to render the constituent ingredients suitable for making new, high quality paper products.
The homogeneous mixture is then maintained at a predetermined temperature 18, such as between about ambient temperature to about 180° F., for example, for a predetermined amount of time, such as about 2 hours, for example. While maintaining the homogeneous mixture at the desired temperature 18, the blending process may be continued to facilitate maintaining a homogeneous mixture, and to possibly aid in further breaking down the recyclable paper stock into its constituent ingredients. Wherein the temperature is desired to be raised above the ambient temperature, the temperature can be attained, by way of example and without limitations, by using preheated water to which the treating solution is added. In the enzymatic process, about 15 gallons of enzymatic solution may be added to about 14,000 gallons of heated process water. In the defoaming process, about 30 gallons of defoaming solution may be added to about 14,000 gallons of heated process water.
Next, the mixture, whether heated above ambient temperature or not, is allowed to stand at ambient temperature (standard room temperature) or about 70° F., for example, until it is applied to the paper manufacturing process. In one embodiment, as the mixture is standing at ambient temperature, the resulting liquid and solid ingredients are able to at least partially separate, and contaminants, such as ink, for example, may be skimmed from the top layer. Alternatively, the mixture can be maintained at any specified temperature by application of heat.
The mixture from 18 in appropriate volume may be fed into a standard paper manufacturing process 26, as shown in FIGS. 1 and 3. Alternatively, the mixture may be further processed by separating the liquid (filtrate) from the pulp (solid constituents) of the broken-down recyclable paper mixture. Various processes of filtering can be used separately or in combination with one another and may include, press belt, gravity filtration, and/or vacuum filtration. The liquid 28 can be treated and, depending upon its condition, either recycled for use in the process where the treating solution is combined with the shredded recyclable paper 14, or sent to a wastewater treatment system 35. The pulp 22 may be rinsed 24 and used as stock in a standard paper manufacturing process 26. As shown in FIG. 1, the mixture from 18 may undergo bleaching 38 and blending 40 before being transferred directly to the standard paper manufacturing process 26 or before being separated into liquid and solid components at 20.
Desirably, the mixture from 18 is fed into the standard paper product manufacturing process 26, such as shown in FIGS. 1 and 3. The mixture may be introduced at a wet end 27 (FIG. 3) of the process 26 to formulate the desired consistency of paper stock. Otherwise, when a filtration step is employed, the recycled pulp can be introduced at the wet end 27 to manufacture paper products having 100 percent recycled paper product content or less, as desired, with the resulting filtrate being recycled to the process where the treating solution is combined with the shredded recyclable paper stock 14, or sent directly to the wastewater treatment system 35 without necessity for additional treatment of the liquid 28, such as neutralizing, for example.
As mentioned, and as shown in FIG. 1, the filtered waste liquid 28 can be recycled for reuse in the paper manufacturing process, or disposed, such as into a wastewater treatment system 35, or some combination thereof. A flocking agent may be added to the waste liquid 30 to separate contaminants, such as inks, by way of example and without limitations, therefrom. Flocking agents may include a mixture of Western Bentonite and other proprietary ingredients, readily available from Wastewater Engineers, Inc., in Oxford, Mich., under item number WE-KM-4, including ingredients such as crystalline silica (SiO₂) or quartz. The waste liquid and flocking agent mixture may then be filtered 32, such as through the use of a vacuum filter, to remove liquid or solid contaminants from the waste liquid. Upon removal of the contaminants, the generally pH neutral waste liquid byproduct 34 from the recycling process is suitable for reuse at 14, or for disposal into the environment, such as via the wastewater treatment system 35, without harming the environment.
Additive in White Water System
Another aspect of the invention includes using the treating solution as an additive in an at least a portion of the recirculatory white water system 36, whether the white water system 36 is a generally open system (FIG. 4) or a generally closed system (FIG. 5). For economic reasons, the white water system 36, which may be defined as the processing liquid used in the paper manufacturing process is collected or partially collected, and generally recirculated, at least in part, regardless of whether the system is an open or closed system. A supply of fresh water 38 is piped into the white water system 36 to maintain the desired level or fluid capacity of the white water system 36. The trend is toward use of a recirculatory closed white water system, wherein white water 40 comprising water, fibers and additives from the stock preparation, for example, is recirculated for a predetermined cycle duration. The white water system 36 captures drained fluid from the wire and/or fabric of a Fourdrinier table 46 (FIGS. 4-5) and may recirculate at least a portion of the fluid via a liquid supply system 41, such as back to a paper stock preparation chamber 39, which incorporates the recycled stock from 18 and/or 24 of FIG. 1 into the paper manufacturing process, and/or downstream therefrom. The treating solution, added to the white water system 36, greatly extends the useful life of the white water 40 and facilitates pulp recovery due to surface tension reduction by the surfactants, thereby reducing the frequency of cleaning and the amount of downtime of the paper manufacturing line for cleaning, while also reducing the amount of fresh water 38 required and consumed in the paper manufacturing process. For example, it has been demonstrated that the use of the treating solution in the white water system 36 can extend the useful life of the white water 40 by about 10% to about 50%.
One way the enzymatic solution extends the useful life of the white water 40 is by preventing the formation of “stickies”, which are known in the art to comprise water insoluble gel particles of coagulated ingredients, such as silicone, latex, and calcium carbonate, for example. Stickies are highly undesirable in a paper manufacturing process, as they can cause dimples and/or perforations in the resulting paper product, which results in the formation of what is termed as “broke” or scrap paper. Additionally, stickies build up on various paper manufacturing machinery components in the wet end 27, thereby increasing the frequency of necessary cleaning and servicing of the machinery, and thus, increasing the downtime of the machinery. Further, if a layer of coating comprising silicone is being applied to the paper product, the enzymatic solution can reduce the amount of silicone ingredient required in the coating. This is due to the presence of liquid silicone in the white water 40, which is brought about by the content of the enzymatic solution within the white water 40 that prevents the formation of stickies. In addition, the pH neutral enzymatic solution also allows for polymeric equipment to be introduced into the paper manufacturing system, thereby resulting in further potential cost reduction.
A white water system 36 may contain between about 10,000 to about 20,000 gallons of liquid. Fresh water 38 is replenished in the white water system 36 via a liquid applying system, represented here as one or more high pressure needle or jet showers 42, for example, used for showering or rinsing the web of paper product prior to pressing. The concentration level by volume can be maintained in the white water mixture by continuously or periodically adding the treating solution to the white water 40, such as through one or more of the jet showers 42, for example. By adding the treating solution through the jet showers 42, an added benefit results from the cleaning of the wire and/or fabric of the Fourdrinier table 46 directly below the jet showers 42. It should also be recognized that additional treating solution may be introduced from the mixture at 18 into the standard paper manufacturing process 28, particularly if the mixture at 18 remains unfiltered.
The enzymatic solution may be particularly useful at reducing biofilms in the system and inhibiting the build up of stickies within the white water 40. The enzymatic solution may be added to the white water 40 to attain a white water mixture having a concentration level between about 0.05% to about 0.1% enzymatic solution by volume within the white water 40. However, the enzymatic solution concentration level in the white water 40 can lessen over time with the addition of fresh water to the white water system 36. Therefore, the 0.1% enzymatic solution concentration level by volume can be maintained in the white water mixture by continuously or periodically adding enzymatic solution to the white water 40, such as through one or more of the jet showers 42, for example. In one embodiment, the enzymatic solution is Silzyme®.
Restorative Boil Out
The wet end 27 must undergo a scheduled restorative cleaning or “restorative boil out”, which may occur about every 6 weeks. Restorative cleaning provides a thorough cleaning of all the machinery components, and culminates by draining the old supply of white water 40 and replenishing the white water system 36 with fresh water. With the treating solution mixed and circulated generally homogenously in the white water 40 during the paper manufacturing process, the frequency of restorative cleaning may be reduced from about every 6 weeks, to about every 8 weeks, and thus, the useful life of the white water 40 may be extended by about 2 weeks. Accordingly, the economic efficiencies of the paper manufacturing process 12 may be improved by reducing the consumption of fresh water 38, by reducing the frequency of machinery downtime, and by reducing the production of broke paper and increasing the tonnage of useful paper product produced over a given period of time. For example, circulating white water containing about 0.1% Silzyme® throughout a standard paper manufacturing process 26 can result in an increase of the saleable paper product value from about $50.00 to about $250.00 per ton of end paper product. This increase in economic efficiency results from the ability of the treating solution to inhibit the build-up of pulp, binders, various additives, and stickies (in the case of enzymatic solutions) on components of the machinery, thereby reducing the frequency of restorative cleanings over a period of time and decreasing the amount of broke paper formation, which relates to an increased output of saleable paper product over a given period of time.
Restorative cleaning is generally performed throughout the wet end 30 of the paper making line with the line in an idle state. The exposed components of the wet end 27, including the interior of a head box 44 (FIGS. 6 and 7), the Fourdrinier table 46, and any rolls and presses, such as a breast roll 48, a couch roll 50, and a dandy roll 51 are sprayed with a treating solution. The treating solution can be applied on the components using a standard hand pump sprayer, for example, or any other type of spray dispensing mechanism. Upon being applied, the treating solution is allowed to stand on the surfaces of the components for a prescribed period of time, such as about 20 to about 30 minutes, or longer, prior to performing the boil out. In one embodiment, the exposed components of the wet end 27 are sprayed with a treating solution of about 10% to about 20% Silzyme® concentrate in water. For example, a 1500 gallon supply of water can be combined with 300 gallons of Silzyme® concentrate to formulate a 20% solution of Silzyme® by volume.
Boil out may be performed by circulating the treating solution-white water mixture at an elevated temperature, via pumps within the white water system 36, such as between about 120° F. to about 165° F. This temperature range, though approximate, is significantly reduced from that of ordinary boil out temperatures, which generally necessarily range between about 180° F. to about 240° F. The reduction in boil out temperature is possible because of the presence of the treating solution in the white water 40, and the additional treating solution sprayed directly on the interior surfaces of the machinery components designated. Accordingly, the amount of energy consumed during a boil out may be greatly reduced. The boil out procedure may be performed for a period between about 1 to about 3 hours. After performing the boil out, the white water 40 and the treating solution mixture can be drained directly into a wastewater treatment system without the necessity of further treatment.
Maintenance Boil Out
Other than during a restorative maintenance cleaning, the white water system 36 may be drained during a scheduled maintenance cleaning or “maintenance boil out” procedure of the wet end 27. Maintenance cleaning is generally conducted at convenient times, such as during changeover between the manufacture of different paper grades, for example. The maintenance cleaning process is similar to the restorative cleaning process except that the concentration of the treating solution may be lower. In one embodiment, the exposed components of the wet end 27 are sprayed with a treating solution of about 1% to about 6% Silzyme® concentrate. The maintenance boil out procedure may be conducted in the same manner as described above for the restorative boil out procedure.
Clean Wire and Fabric Surfaces of Fourdrinier Table
Restorative and maintenance cleaning can also be performed on the wire and/or fabric surface of the Fourdrinier table 46. To clean the wire and/or fabric while in place, generally referred to “clean-in-place” (CIP), the treating solution is applied, such as by spraying via a hand held spray applicator, for example, to the entire outer surface thereof. The treating solution is allowed to stand for a prescribed amount of time, such as about 20 to about 30 minutes, for example. Then, a power washing operation is performed by spraying the wire and/or fabric with water at about 800 psi, wherein the water may be sprayed at a temperature of about 120° F. to about 140° F. The resulting water and the treating solution can drain into the white water system 36, where it can remain until it is time to drain the white water 40 into a wastewater treatment system, such as during a restoration or maintenance boil out. In one embodiment, the treating solution is about 6% Silzyme® concentrate.
To perform a restorative cleaning of the wire and/or fabric, the treating solution is maintained at a temperature of about 120° F. to about 165° F. The wire and/or fabric is allowed to soak for about 20 to about 30 minutes. Afterward, the system boil out is run at a temperature of about 120° F. to about 165° F. The resulting water and the treating solution can be drained into a wastewater treatment system. The wire and/or fabric can then be returned to production. In one embodiment, the treating solution is about 1% to about 6% Silzyme® concentrate.
To perform a COP maintenance cleaning of the wire and/or fabric, upon removal of the wire and/or fabric, the treating solution is sprayed on the outer surface. The treating solution is allowed to stand for about 20 to about 30 minutes, and then it is rinsed off with a spray power washer, where the pressure of the water is at about 800 to about 3000 psi and the temperature of the water is about 120° F. to about 165° F. The resulting water and treating solution can be drained into a wastewater treatment system. The wire and/or fabric can then be reinstalled. In one embodiment, the treating solution is about 1% Silzyme® concentrate.
Clean Filters
The white water system 36 generally has one or more filters (not shown) to remove impurities, including, by way of example and without limitation, pulp residue, stickies (in the case of enzymatic processes), calcium carbonate, binders, and other additives. The filters generally also require periodic cleaning, which can be facilitated with the treating solution. The filters are removed and fully submerged in a bath of the treating solution, which may be maintained at about 120° F. The filters may be soaked within the treating solution for a prescribed period of time, such as about 20 to about 30 minutes, for example. The filters are then removed and power washed with water at about 800 to about 3000 psi and a temperature of about 120° F. to about 165° F. The resulting water and the treating solution can be drained into a wastewater treatment system, and the filters reinstalled for continued use. In one embodiment, the treating solution is about 20% Silzyme® concentrate.
Clean Coater System
Downstream from the wet end 27 of the paper manufacturing process, a coater system 60, as shown in FIG. 6, can be used to apply various coatings, such as, pigments, binders, and additives (i.e. insolubilizers, plasticizers, preservatives, and dyes), for example, to the paper product. The coater system 60 has a separate fluid system (not shown) from the white water system 36, and thus, has a separate tank for maintaining the type of coating being applied. Over time, the coater system 60 may acquire a buildup of coating ingredients thereon, and thus, needs to be periodically cleaned. The coater system 60 can be cleaned using a restorative boil out process, or a maintenance boil out process.
In the restorative boil out process, any filters within the coater system 60 may be removed and cleaned as described above. Then, about a 10-20% Silzyme® solution is circulated through the system at about 120° F. to about 165° F. for about 2 to about 3 hours. Accordingly, in a 2000 gallon capacity coater system, the 20% Silzyme® solution can be formulated by mixing 400 gallons of Silzyme® concentrate in 1600 gallons of water, wherein the water may be heated to about 120° F. After the boil out process is completed, the cleaned filters are replaced, and the water, having a temperature of about 120° F., may be circulated throughout the coater system 60 for about 10 to about 20 minutes. The heated water in the coater system 60 is then drained into a wastewater treatment system, and the coater system 60 is ready for use.
To perform the maintenance cleaning of the coater system 60, about 1% to about 6% Silzyme® solution is circulated through the system 60 at about 120° F. to about 165° F. for about 2 to about 3 hours. During the maintenance cleaning, the filters can be left in place. Accordingly, in a 2000 gallon capacity coater system 60, the 6% Silzyme® solution can be formulated by mixing 120 gallons of Silzyme® concentrate in 1880 gallons of water, and thereafter may be preheated to about 120° F. to about 165° F. Upon completing the boil out, the system 60 is drained directly into a wastewater treatment system. The coater system 60 is then filled with fresh water having a temperature of about 120° F., wherein the water is circulated throughout the system 60 for about 10 to about 20 minutes. The heated water is then drained into a wastewater treatment system, and the coater system 60 is ready for reuse.
The coater system 60 and filters can be surface cleaned by applying about 10% to about 20% Silzyme® solution, via a hand held spray applicator, for example, to their outer surfaces. Upon being sprayed onto the outer surfaces, the Silzyme® solution is allowed to stand for about 20 to about 30 minutes. The Silzyme® solution is then rinsed off with high pressure water from a power washer at about 800 to about 3000 psi. This process can be repeated as often as necessary to achieve the desired degree of surface cleaning.
FIG. 8 illustrates one embodiment of a paper making facility which combines the recyclable paper process with a paper manufacturing process. Recyclable paper is brought to a sorting area 6 where the paper products are sorted by composition. For example, recyclable paper comprising release paper products, such as those used as backing for stickers, newsprint, colored and/or coated box paper product, and coated corrugated cardboard may be separated into one category for recycling with an enzymatic solution. Recyclable paper comprising wax-coated cartons (WCC), box paper product, and corrugated cardboard (e.g., “old” corrugated cardboard (OCC)) may be separated into another category for recycling with a defoaming solution. The sorted paper serves as recyclable paper stock for the paper manufacturing process and may be housed in a storage unit 5 until ready for use.
The recyclable paper may be processed according the steps illustrated in FIG. 1. The recyclable paper stock is taken to a shredding area 2 to be shredded into smaller pieces. The shredded paper is then transferred to batch tanks 3 where it is combined with a treating solution and blended to form a substantially homogeneous mixture. The homogeneous mixture may be further processed according to the steps outlined above with respect to FIG. 1 to form stock for the paper manufacturing process 7.
The stock from the recycling process is delivered to a head box 44 (FIGS. 3, 6 and 7) at the wet end 27 of a paper manufacturing line. The head box 44 uniformly delivers stock from the recycling process onto a paper web conveying system comprising, for example, a wire or plastic mesh. A processing liquid, such as the white water system 36 in FIGS. 4 and 5, is applied to the stock on the conveying system. The liquid drains through the mesh while paper pulp remains evenly distributed on the conveying system to form a web. A liquid processing system, such as the white water system 36 in FIGS. 4 and 5, captures the liquid passing through the conveying system and recirculates at least a portion of the liquid to the conveying system. As the liquid drains from the paper pulp, the fibers form a more cohesive web. A vacuum may be introduced underneath the web while a dandy roll rides on the upper surface of the web gently pressing it. The web may then be separated from the belt and deposited on felt. The felt is carried between rollers to further remove water from the web. At this point, the water content may be reduced to about 65%. The felt is then passed around a series of heated roller to dry the web to a moisture content of about 3% to about 4% and through several calendar stacks to smooth the paper. The paper may be coated and/or have the moisture content adjusted prior to being wound on rollers.
The treating solution may be added to the recirculatory white water system of the paper manufacturing process to clean the internal and external components of the machinery in the paper manufacturing line as described above. Additionally, as described above, the treating solution may be used during restorative cleaning of the machinery, maintenance cleaning of the machinery, cleaning of the wire and fabric surfaces of the Fourdrinier Table, cleaning of filters and cleaning of a coater system, all as described above.
It is to be understood that the embodiments discussed above are exemplary embodiments, and thus are intended to be illustrative and not limiting. For example, the treating solution can also be used directly in the standard paper product manufacturing process 26, regardless of whether recycled paper is being used. The treating solution can be added to processed pulpwood used in the process 26 to reduce the surface tension of the paper pulp constituents, thus, providing a more homogeneous blend of paper pulp. As such, the likelihood of “broke” being formed is reduced.
Thus, the invention provides, among other things, related to processes used in the manufacture of paper products. Various features and advantages of the invention are set forth in the following claims.

Claims

1. A process for recycling paper product, comprising:

shredding recyclable paper product;

adding an enzymatic surfactant penetrant treating solution to the shredded paper product to form a mixture including a liquid and solid constituents;

blending the mixture; and

introducing the mixture into a wet end of a paper manufacturing process.

2. The process of claim 1, wherein the recyclable paper product comprises at least one of backing for stickers, newsprint, colored coated box paper product, coated box paper product, coated corrugated cardboard, and combinations thereof.

3. The process of claim 1, wherein the recyclable paper product comprises at least one of a latex coating, a silicone coating and combination thereof.

4. The process of claim 1, wherein the enzymatic surfactant penetrant treating solution comprises Silzyme®.

5. The process of claim 1, wherein the mixture comprises about 50% to about 90% enzymatic surfactant penetrant treating solution.

6. The process of claim 3, further comprising blending the mixture at least long enough to separate the paper fibers from the latex coating, silicone coating or combination thereof.

7. The process of claim 1 wherein the mixture has a pH from about 5 to about 8.

8. The process of claim 1 including filtering the mixture into a liquid and solid constituents and introducing the solid constituents into the wet end.

9. The process of claim 8 including adding a flocking agent to the separated liquid to remove contaminants therefrom.

10. The process of claim 8 including recycling the liquid for reuse in the process for recycling paper product.

11. The process of claim 8 including releasing the liquid directly into a wastewater treatment system.

12. A process for recycling paper product, comprising:

shredding recyclable paper product;

adding a defoaming surfactant penetrant treating solution to the shredded paper product to form a mixture including a liquid and solid constituents;

blending the mixture; and

introducing the mixture into a wet end of a paper manufacturing process.

13. The process of claim 12, wherein the recyclable paper product comprises at least one of wax-coated cartons, box paper products, and corrugated cardboard.

14. The process of claim 12, wherein the mixture comprises about 50% to about 90% defoaming surfactant penetrant treating solution.

15. The process of claim 12 wherein the mixture has a pH from about 5 to about 8.

16. The process of claim 12 including filtering the mixture into a liquid and solid constituents and introducing the solid constituents into the wet end.

17. The process of claim 16 including adding a flocking agent to the separated liquid to remove contaminants therefrom.

18. The process of claim 16 including recycling the liquid for reuse in the process for recycling paper.

19. The process of claim 16 including releasing the liquid directly into a wastewater treatment system.

20. A process for manufacturing paper product, comprising:

providing pulpwood;

processing the pulpwood in a standard paper manufacturing process;

adding an enzymatic surfactant penetrant liquid treating solution to the processed pulpwood to create a homogeneous mixture; and

introducing the mixture into a wet end of the standard paper manufacturing process.

21. A method of treating the components of a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a paper web conveying system, the conveying system having a liquid applying system for application of liquid to the stock which allows liquid to drain, while the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to use in the production of the paper, the method comprising:

while the line is idle, adding a surfactant penetrant treating solution to the white water system to create a white water mixture and circulating the mixture through the conveying system;

draining the mixture into a wastewater treatment system; and

refilling the white water system with water for continued use.

22. The method of claim 21 wherein the surfactant penetrant treating solution comprises an enzymatic agent.

23. The method of claim 21 wherein the surfactant penetrant treating solution comprises a defoaming agent.

24. The method of claim 21 wherein the pH of the surfactant penetrant treating solution is about 5 to about 8 and the head box has a liquid supply system to which the white water mixture is supplied.

25. The method of claim 21 wherein the mixture is heated to a temperature of about 120° F. to 165° F. and the heated mixture is circulated through the conveying system.

26. The method of claim 21 wherein the mixture is circulated through the conveying system for about 1 to about 3 hours.

27. The method of claim 21 wherein the components of the paper manufacturing line comprise at least one of a head box, a Fourdrinier table, a breast roll, a couch roll and a dandy roll.

28. The method of claim 21 wherein the paper stock comprises a mix of recyclable waste paper and new stock paper.

29. The method of claim 21 further comprising spraying the components of the paper manufacturing line with the surfactant penetrant treating solution prior to circulating the white water mixture through the conveying system.

30. The method of claim 29 wherein the surfactant penetrant solution is about 1% to about 6% Silzyme® concentrate.

31. The method of claim 29 wherein the surfactant penetrant solution is about 10% to about 20% Silzyme® concentrate.

32. The method of claim 31 wherein the surfactant penetrant solution is allowed to stand on the surfaces of the components for about 20 to about 30 minutes before the white water mixture is circulated through the conveying system.

33. A method of preventing the formation of water insoluble particles of ingredients known as stickies in the white water system of a paper manufacturing line incorporating a paper stock preparation chamber for feeding paper stock to a head box for uniformly distributing the paper stock onto a paper web conveying system, having a liquid applying system for applying water to the stock which allows liquid to drain while pulp from the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained white water to aid in the production of the paper stock, the method comprising:

adding an enzymatic surfactant penetrant treating solution to the white water system to formulate an enzyme containing white water mixture; and

recirculating the enzyme containing white water mixture to the fluid applying system while forming the web on the paper web conveying system.

34. The method of claim 33 wherein the enzymatic surfactant penetrant treating solution is added to formulate between about 0.05% to about 0.1% enzyme containing solution by volume within the white water mixture.

35. A method of treating the components of a paper manufacturing line incorporating a paper stock preparation chamber for feeding paper stock to a head box for uniformly distributing the paper stock onto a paper web conveying system, having a liquid applying system for applying water to the stock which allows liquid to drain while pulp from the paper stock remains evenly distributed on the conveying system to form a web, presses for receiving the web and further removing liquid, and a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained white water to aid in the production of the paper stock, the method comprising:

adding an defoaming surfactant penetrant treating solution to the white water system to formulate a defoaming containing white water mixture; and

recirculating the defoaming containing white water mixture to the fluid applying system while forming the web on the paper web conveying system.

36. A method of cleaning a portion of a paper manufacturing line that includes a head box for uniformly distributing paper stock onto a liquid-sprayed paper web conveying system that allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, a white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid, the method comprising the steps of:

spraying an aqueous solution to cover surfaces of a portion of the manufacturing line, the aqueous solution comprising a surfactant-penetrant-releasing agent; and

rinsing the solution from the portion of the manufacturing line where the solution was sprayed.

37. The method of claim 36 in which, in the step of spraying an aqueous solution, the solution further includes a defoaming agent.

38. The method of claim 36 in which, in the step of spraying an aqueous solution, the solution is an enzymatic solution solution.

39. A method of cleaning a coater system of a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a liquid sprayed paper web conveying system, which allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid prior to the web reaching the coater system, the method comprising:

while the line is idle spraying an enzymatic surfactant penetrant treating solution to cover surfaces of the coater system; and

rinsing the enzymatic surfactant penetrant treating solution from the coater system.

40. The method of claim 39 wherein the enzymatic surfactant penetrant treating solution is allowed to stand on the surface of the coater system for about 20 to about 30 minutes.

41. The method of claim 39 wherein the enzymatic surfactant penetrant treating solution is rinsed form the coater system with about 800 to about 3000 psi of water.

42. The method of claim 39 wherein the enzymatic surfactant penetrant treating solution is about 10% to about 20% Silzyme® concentrate.

43. A method for cleaning filters in a paper manufacturing line incorporating a head box for uniformly distributing paper stock onto a liquid sprayed paper web conveying system, which allows liquid to drain while paper pulp remains evenly distributed on the conveying system to form a web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the web, and presses for receiving the web and further removing liquid prior to said web reaching the coater system, the method comprising:

removing the filters from the paper manufacturing line;

submerging the filters in a bath comprising a surfactant penetrant treating solution;

removing the filters from the bath; and

washing the filters with high pressure water.

44. The method of claim 43 wherein the bath is maintained at a temperature of about 120° F.

45. The method of claim 43 wherein the pressure of the high pressure water is about 800 to about 3000 psi and the temperature of the high pressure water is about 120° F. to about 165° F.

46. The method of claim 43 wherein the bath comprises about 20% of Silzyme® concentrate.

47. A method of making paper in a paper manufacturing line incorporating a head box for uniformly distributing paper pulp stock onto a liquid sprayed paper web conveying system which allows liquid to drain while paper pulp stock remains evenly distributed on the conveying system to form a paper web, an enzyme containing white water system for capturing at least some of the drained liquid and recirculating at least some of the drained liquid to the conveying system to aid in the production of the paper web, the method comprising:

adding enzymatic surfactant penetrant treating solution to the white water system.