JPH02182995A - Protection method against extraction on felt or the like of paper machine - Google Patents

Abstract

PURPOSE: To provide a method for preventing a sticky material from depositing on paper machine felts and other device parts by applying a cationic polymer- containing water solution and specific water solution thereon. CONSTITUTION: This method is carried out by applying a water solution containing at least about 2 ppm of a cationic polymer and a water solution containing a nonionic or cationic surface-active agent onto press felts 12, 14, 16 and 18 in any place of respective returning steps by using e.g. showering devices 50, 51, 52 and 53. The surface-active agent is used in an amount effective to inhibit build-up of deposits derived from the cationic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to the provision of clean and uncontaminated papermaking felts and other equipment, and more particularly to the chemical treatment of papermaking felts and other equipment to prevent the deposition of sticky substances.

SUMMARY OF THE INVENTION A method is provided for treating papermaking felt and other equipment to prevent the deposition of sticky materials thereon, the method comprising: (a) applying at least about (b) applying an aqueous solution containing 2 ppm of a cationic polymer to the device component; applying an amount effective to prevent the accumulation of deposits derived from the cationic polymer. Cationic surfactants are preferred. In particular, it has a molecular weight of about 200 to 800 and has the general formula selected from the group consisting of aryl and aralkyl groups, at least one of the R groups is alkyl having at least 8 carbon atoms, and X- anion indicates l/n of the n-valent anion; Disclosed is the use of water-soluble surfactants having . Compositions comprising the cationic polymer and the surfactant in a weight ratio of about 50:1 to about 1:1 have been shown to be particularly useful.

Background of the Invention Paper manufacture typically consists of processing a carefully prepared aqueous suspension of fibers to produce a highly uniform dry sheet. Typically, there are three steps: a sheet forming step in which the aqueous suspension is poured over a porous wire mesh onto which the fibers are deposited, while the liquid is filtered through the wire mesh; The paper is passed through a press wrapped in plastic felt to extract any remaining water from the sheet, improve the uniformity of the sheet and give it surface quality, and a paper drying process that evaporates any remaining water. Become. The resulting sheet can be further processed into a final paper product.

It is widely known that water evaporation is energy intensive and relatively expensive. Efficiency in papermaking therefore depends on avoiding drawbacks such as dewatering during the sheet forming and processing steps, resulting in dry sheets that are unsuitable for use. Felt and wire mesh are particularly important because they not only remove moisture, but also affect the quality of the paper itself due to their close contact with the sheet. Precipitates that collect on the felt or wire mesh can also affect the efficiency of moisture removal and can cause holes in the sheet, or they can transfer onto the sheet and become a defect.

The quality of the aqueous fiber suspension used in paper manufacturing depends on the wood and water used as raw materials, the composition of recycled materials added to the manufacturing process, and the additives used during suspension manufacturing. depends on many factors. A number of soluble or suspendable substances that can be added to the manufacturing process include inorganic substances such as salts and clays, and natural organic substances such as resins or pitches from wood, and inks, latex, and adhesives from recycled paper products. Both agents are mentioned. It has been recognized that during the papermaking process, deposits containing inorganic and/or organic materials can accumulate on felt and other sheet forming equipment, interfering with an efficient papermaking process. A particular nuisance is sticky substances such as glues, resins, rubbers, etc. that are present with the recycled fibers.

A method for quickly and effectively removing deposits from paper machine sheet forming equipment is of great importance in the industry. Paper machines can be stopped for cleaning, but stopping operations for cleaning results in a loss of productivity.
Undesirable. Online cleaning, which can be carried out effectively, is highly preferred.

The belt-shaped or cylindrical wire mesh used to form the sheet is continuously circulated as a belt during papermaking. In this cycle, the sheet contact section begins where the fiber suspension is fed to the wire mesh belt or where the cylindrical wire mesh starts and ends where the formed sheet moves away from the wire mesh surface. In the return portion of this circulation, the wire mesh returns to the sheet contact portion from the position where the formed sheet is away from the surface of the wire mesh.

In belt-shaped wire meshes, such as Fourdrinier wire meshes, on-line (in-operation) wire mesh cleaning has generally been carried out during its return phase (i.e., where the wire mesh does not come into contact with the forming sheet) by subjecting the returning wire mesh to a cleaning solution. (
A typical example is water). Sometimes the wire mesh is sprayed with pressurized liquid. Spraying helps mechanically clean the wire mesh surface. Water injection, with or without mechanical devices, does not completely satisfactorily prevent the accumulation of organic compounds or inorganic deposits on the wire mesh, and furthermore, the use of additives A more effective cleaning solution has been prepared and used.

Most fibrous or inorganic materials have been successfully removed using aqueous formulations containing acids or alkalis, as well as other chemicals such as surfactants.

Where organic precipitates predominate, they have been removed with some success using organic solvents, including some formulations containing low flash point aromatics or chlorinated hydrocarbons.

In some spinning machines, finely perforated fabric belts are used in place of traditional wire mesh.

Papermaking felts are also commonly cycled continuously between a sheet contact stage and a return stage in a belt system. During the sheet contacting step, water is drawn from the sheet into the pores of the felt, usually under pressure and/or vacuum. A clean felt with relatively open, fine pores is particularly desirable for efficient papermaking because it effectively removes water from the paper sheet. The felt cleaning process maintains the porosity of the felt by removing organic and inorganic material, both from the entire device and from specific locations. and fuzz generation must be controlled without chemically or physically affecting the web. Mechanical removal, typically by contact with a blade, has removed debris from the felt surface.

However, cleaning solutions are also used to remove troublesome build-up of organic and inorganic deposits. The fabric composition and construction of many papermaking felts makes them susceptible to chemical degradation. Cleaning chemicals must be easily removed by rinsing. Continuous cleaning and impact (5hoc) are used in many paper making machines.
k) both scavenging are used. The chemicals used include organic solvents, often chlorinated hydrocarbons. Acid and alkali based systems are also used, but at lower concentrations than for wire mesh cleaning. High concentrations of alkali metal hydroxides are unsuitable for felt cleaning because they attack felt fabric materials.

It has been concluded that some of the more effectively used organic solvents are hazardous to health, eg carcinogenic, and require particularly careful handling. Other solvent-based products can damage plastic or rubber components used in the papermaking process. We know that an on-line method for felting has been used successfully for several years, and the method uses cationic surfactants,
For example, an aqueous solution of alkyldimethylbenzylammonium chloride, where the alkyl group is C1□)I2s, C,
H, and a mixture of C1, H33 groups are in contact with each other. However, experience has shown that even after treatment with these surfactants, certain sticky substances tend to adhere to the felt. Another felt conditioning method that has been advocated in the past is to apply an aqueous solution of a cationic polymer to the felt. However, this type of treatment can actually result in the accumulation of precipitates derived from the cationic polymer itself.

Other sheet forming equipment, such as a decker
seeds), filters, sieves, and rollers can also become contaminated with slime. The problems and treatment methods during the process are roughly the same as those for felt systems, except for maintaining porosity,
Considerations that are important in cleaning felt and other microporous device components, such as preventing fabric chemical degradation, are less critical in other equipment.

The natural resin or gum in new wood varies depending on its type. Some species of pinewood, especially those containing more than 2% by weight of resin, are used at very low rates due to problems with their gums and resins. Papermaking alum, or sodium aluminate, is traditionally used to prevent natural resin precipitation. These products are added to the entire pulp system to precipitate the resin onto the fibers. The effectiveness of this method is limited by factors such as pH % corrosivity, paperability, and the need to control interactions with other chemicals in the pulp system. A solution that would allow these problematic pinewood resources to be used without any restrictions would provide significant economic advantages to pulp and paper manufacturers.

As the use of recycled fibers becomes more common, the build-up of sticky substances during papermaking is becoming increasingly serious. Thickeners, resins, gums, and other substances found in the circulating secondary fibers tend to adhere to various parts of the paper making machine and are difficult to remove by on-line water injection cleaning. Substances that adhere to felt can seriously affect dewatering and papermaking. This can result in holes in the product and, ultimately, in the sheet tearing during papermaking. It is often necessary to stop the machine and wash the felt with a solvent, especially to remove sticky substances associated with circulating fibers. The benefits of paper resource circulation are somewhat diminished because the productivity of paper machines decreases.

Certain organic cleaning agents often used in the past are no longer environmentally desirable. Thus, there is an increasing need to develop cleaning agents that remove organic deposits without posing environmental hazards. Naturally, the formulation used must not be such that it will destroy the felt or other papermaking equipment. Certain substances are thought to work satisfactorily under certain conditions, but
There is still a need for more effective anti-sedimentation agents for papermaking, especially when recycled fibers are used as raw materials.

Another method of preventing precipitation has been to use pulp additives such as anionic arylsulfonic acid-formaldehyde condensates or cationic dicyandiamide-formaldehyde condensates. These additives can function as sequestrants, dispersants or surfactants. In particular, cationic dicyandiamide-formaldehyde aminoplast resins are suitable for pitch (
(e.g. resinous substances and gums) to form discrete particles, and the pitch particles are said to be uniformly dispersed on the pulp fibers. As a result, the amount of pitch that accumulates in the paper machine is reportedly reduced and there is no black dots, pitch stains or scratches on paper products.

SUMMARY OF THE INVENTION The present inventors have disclosed that the deposition of adhesive substances from paper pulp onto papermaking equipment used to convert papermaking felts and other pulp slurries into sheets is controlled by the present inventors at a concentration of at least 2 ppm in such equipment. applying an aqueous solution of a cationic polymer and applying an aqueous solution of a water-soluble nonionic and cationic surfactant to the device containing an amount effective to prevent the buildup of deposits derived from the cationic polymer; We have discovered that this can be prevented by applying a coating. Preferably, the aqueous solution containing the cationic polymer and surfactant is substantially free of anionic polymers. Preferred cationic polymers include protonated or quaternary ammonium polymers, such as those produced by the reaction of epihalohydrin with dimethylamine or diethylamine. Preferred cationic surfactants include alkyldimethylbenzyl ammonium chlorides having an alkyl group having 12 to 16 carbon atoms. The present invention is particularly effective when used to treat felt and other equipment used in processing pulp slurry into sheets.

An object of the present invention is to provide a method that can effectively prevent substances from depositing on paper manufacturing equipment.

Another object of the present invention is to provide a method for preventing deposits in paper machines that effectively improves papermaking processes using recirculating or high resin content pinewood pulp fibers.

Yet another object of the present invention is to provide a means for improving productivity and product quality in a paper manufacturing process.

These and other objects and advantages of the invention will become apparent from the following detailed description of the invention.

DETAILED DESCRIPTION The present invention uses aqueous solutions of certain water-soluble cationic polymers and certain water-soluble surfactants to form felt or other sheet-forming devices, particularly porous components of other devices. The present invention is directed to substantially preventing the accumulation of organic and inorganic precipitates. Treatment with a combination of cationic polymer and cationic surfactant provides surprisingly effective prevention of deposition on the treated equipment, even when a significant portion of the pulp formulation is accounted for by recycled fibers. The present invention provides a particularly effective felt cleaner and paper machine conditioner.

The present invention is broadly applicable, making precise use of the properties of the polymers, and a fairly wide range of different polymers can be used, provided the polymers are cationic. The use of polyethyleneimine is also disclosed in U.S. Pat. No. 3,250,664,
3.642,572, 3.893.885, and 4,250.229 have been used; It is considered to be within the scope of the present invention. However, it is generally preferred to use protonated or quaternary ammonium polymers. These preferred polymers include those obtained by the reaction of epihalohydrin with one or more amines, and those derived from ethylenically unsaturated monomers containing quaternary ammonium groups. The cationic polymers of the present invention also include dicyandiamide-formaldehyde condensates. This type of polymer is described in U.S. Pat. No. 3,582.
No. 461 and is fully included therein. Either formic acid or ammonium salts, particularly preferably both formic acid and ammonium chloride, may also be included as polymerization reactants.

However, certain dicyandiamide-formaldehyde condensates tend to aggregate in felts and the like even in the presence of cationic surfactants. Polymers of the dicyandiamide-formaldehyde type are commercially available, e.g.
Ltd. (Ontario, Canada) from Tinof
ix QF, which contains as active ingredient about 50% by weight of a polymer believed to have a molecular weight of about 20,000 to 50,000.

Among the quaternary ammonium polymers derived from epihalohydrin and various amines, there is an ammonium polymer obtained by reacting epihalohydrin with at least one amine selected from the group consisting of dimethylamine, ethylenediamine, and polyalkylene polyamine. be. Triethanolamine can also be included in the reaction.

Examples include polymers obtained by reaction of polyalkylene polyamines with epichlorohydrin, and polymers obtained by reaction of epichlorohydrin, dimethylamine, and ethylene diamine, or with either one polyalkylene polyamine. It is being Typical examples of amines that can be used are N, N, N'', N'-tetramethylethylene-diamine and ethylenediamine, used together with dimethylamine and triethanolamine.

Examples of this type of polymer include those having the following formula, where A is 0 to 500. Of course, other amines can also be used.

Cationic polymers preferably used in the present invention include:
Included are polymers obtained by reacting dimethylamine, diethylamine, or methylethylamine, preferably dimethylamine or diethylamine, with epihalohydrin, preferably epichlorohydrin.

Polymers of this type are disclosed in and included in US Patent No. 3,738.945 and Canadian Patent No. 1,096,070 in their entirety. Such polymers include Agef 1ocA-50, Agefloc A
-50HV and Agefloc B-50, CP
Commercially available from S Chemical Co., Inc., New Chassis, USA. These three products each contain about 50% by weight as active ingredient and have a molecular weight of about 75.00 to go, ooo, about 200.000, respectively.
from 250,000 to about 20,000 to 30
,000 polymers. Another commercially available product of this type is Magnifloc 573C
So, this is American Cyanamide Co.
mpany (New Chassis, U.S.), and the active ingredient has a molecular weight of about 20,000 to 30,000
It is believed to contain approximately 50% by weight of 000 polymer.

Typical cationic polymers derived from ethylenically unsaturated monomers that can be used in the present invention include vinyl compounds, such as CI to CI8 alkyl halides, benzyl halides, especially chloride, or quaternized with dimethyl or diethyl sulfate. or vinyl pyridine or vinyl imidazole, which may have the formula % where R1, R2 and R3 are each independently lower alkyl, typically having 1 to 4 carbon atoms;
, R2 and R3 can be alkyl having 1 to 18 carbon atoms, such as benzyl vinyl chloride, diallyldimethylammonium chloride, which may be quaternized with a tertiary amine;
Allyl compounds, alkyl halides having 1 to 18 carbon atoms, benzyl halides, or acrylic acid derivatives which may be quaternized with dimethyl or diethyl sulfate, such as dialkylaminomethyl (meth)acrylamide, methacrylamide propyl tri( CI-〇a-alkyl, especially methyl) ammonium salt, or (meth)acryloyloxyethyl tri(CI-C4-alkyl,
especially methyl) ammonium salts, which salts are halides, especially chlorides, methosulfates, ethosulfates, or n
- derived from homopolymers and copolymers of salts that are l/n of the valent anion. These monomers are (meth)acrylic acid derivatives, such as acrylic acid amides, acrylic acid or methacrylic acid C,-C,-alkyl esters, or acrylonitrile, or alkyl vinyl ethers,
Can be copolymerized with vinyl pyrrolidone or vinyl acetic acid. A typical polymer of this type is a 10 to 100 mole percent ammonium polymer having repeating units of the formula R+, where R1 is hydrogen or lower, typically 1 to 4. R2 represents an alkyl group having a long chain, typically 8 to 18 carbon atoms, and R3, R4 and R8 independently represent hydrogen or a lower alkyl group. , and X is an anion, typically representing a halide ion, methosulfate ion, ethosulfate ion, or l/n of an n-valent anion.

Examples include diallyldimethylammonium chloride having a quaternary repeating unit derived from other unsaturated monomers.

Although the polymer contains cyclic groups, they are linearly connected and have no crosslinks, so they should be considered substantially linear.

Other polymers derived from unsaturated monomers that can be used in the present invention include: where Z and Z' can be the same or different, and -C
H,C) I=CH~, -CH2-CHoHCH2-, Y and Y'' can be the same or different, and X or -NR'R'', where X has an atomic weight greater than 30 halogen, n is an integer from 2 to 20, and R' and RI+
(i) are alkyl groups which may be the same or different and have 1 to 18 carbon atoms and may optionally be substituted by 1 or 2 hydroxy groups, or ( (ii) N [together with the atoms represents a saturated or unsaturated 5- to 7-membered ring; or (ii) together with the N and O atoms represents an N-morpholino group. It will be done. Particularly preferred among such polymers are poly(dimethylbutenyl)ammonium cucoride, bis-(triethanolammonium chloride).

Another type of polymer that can be used in the present invention and is derived from ethylenically unsaturated monomers is polybutadiene, which is reacted with a lower alkylamine and some of the resulting dialkylamino groups are quaternized. Therefore, the same polymer has repeating units of the following formula %)) respectively a: t),: b2:
It will have a molar ratio of c. In this formula, R represents a lower alkyl group, typically a methyl or ethyl group.

It is to be understood that the lower alkyl groups need not all be the same. Typical quaternizing agents include methyl chloride, dimethyl sulfate. The ratio of a:bl:b2:c varies with the amount of amine, with (bl+b2) generally ranging from IO to 90% and (a+b) from 90 to 10%. These polymers can be obtained by reacting polybutadiene with carbon monoxide and hydrogen in the presence of a suitable lower alkyl amine.

Other cationic polymers that interact with the anionic polymers and/or sticky substances in the paper pulp may also
It can be used within the scope of the present invention. These include cationic tannin derivatives, such as those obtained by the Mannich reaction of tannins (phenol condensates) with formaldehyde and amines, in the form of salts such as acetates, formates, hydrochlorides or in quaternized form, as well as crosslinked polyamines. Polymers such as epichlorohydrin crosslinked polyamidoamine/polyethylene polyamine copolymers are contemplated to be included. Modified to contain cationic groups I; believed to be useful with natural gums and starches.

The molecular weights of the polymers most useful in this invention are generally about 2.
000 to about 3,000. OOO, but 2.00
Polymers less than 0 and more than 3,000,000 may also be used to some extent. The molecular weight of the polymer used is preferably at least about 10,000, most preferably at least about 20,000. The molecular weight of the polymer used is preferably 300,000 or less, most preferably 50,000 or less. The most preferred polymers have molecular weights ranging from about 20,000 to about 50,000. Mixtures of these polymers can also be used.

The present invention is broadly applicable to both nonionic and cationic surfactants, where applicable, and a fairly wide range of surfactants can be combined with the polymer component as long as they are water soluble. can be used. Suitable nonionic surfactants include ethylene oxide and hydrophobic molecules such as higher fatty alcohols, higher fatty acids, alkylphenols, polyethylene glycols, long chain fatty acid esters, polyhydric alcohols and their partially etherified esters. or a condensation product with an esterified long-chain polyglycol. A combination of these condensates can also be used.

Cationic surfactants are generally preferred. Particularly preferred cationic surfactants suitable for use in the present invention have a molecular weight of about 200 to 800 and - up to % formula % where each R is independently hydrogen, a polyethylene oxide group, a polypropylene oxide group. R groups selected from the group consisting of alkyl groups, aryl groups, and aralkyl groups having about 1 to 22 carbon atoms, wherein at least one of the R groups has at least 8 carbon atoms, preferably about 12 carbon atoms; or 16
is an alkyl group having 5 carbon atoms, and X- is an anion, typically a halide (eg chloride) ion or l/n of an n-valent anion. Mixtures of these compounds can also be used as surfactants in the present invention.

Two of the R groups of the cationic surfactant of the formula are benzyl, preferably selected from the group consisting of methyl and ethyl. Particularly useful surfactants thus include alkyldimethylbenzylammonium chlorides having alkyl groups of about 12 to 16 carbon atoms. This type of commercial product contains approximately 50% surfactant (all)
l! Alkyldimethylbenzyl having a sn-alkyl group, about 40% of the surfactants have a C,,H2,n-alkyl group, and about 10% of the surfactants have a C,@H33n-alkyl group. It is a mixture of ammonium chloride.

This product is known to have a microbicidal effect.

Surfactants considered suitable for use in the present invention also have a molecular weight of from about 1.000 to about 26,000, with a maximum of NR,R2R, where R1 and R2 are polyethers. A group of pseudocationic substances is included, such as polyethylene oxide, polypropylene oxide, or a mixed chain of ethylene oxide and propylene oxide, and R1 is selected from the group consisting of polyether, alkyl group, or hydrogen. Surfactants of this type are disclosed, for example, in US Pat. No. 2,979.528.

The inventors have discovered that when the cationic polymers of the present invention are applied to felt in conjunction with nonionic and/or cationic surfactants, the accumulation of sticky deposits on the felt is reduced. Effectively prevents adhesion of sticky substances, especially when recycled fibers are used. Thus, the present invention
It is particularly advantageous in papermaking systems that use significant amounts of recycled fibers, for example at least 10%. Furthermore, systems in which recycled fibers accounted for at least 70% of the total fibers, and even when the papermaking pulp fibers were derived from 100% recycled fibers, gave outstanding results. The present invention is also believed to particularly advantageously prevent resin precipitation from fibers derived from pine wood containing substantially more than 2% resin by weight (eg, more than 5%).

Although the mechanism of these phenomena is not completely understood, it is likely that the adhesive substances contained in recycled fibers are generally hydrophobic, and that the substances produced by the interaction of these hydrophobic substances with the cationic component of the present invention are , is believed to be very easy to associate with water. As a result, the applied adhesive substance substantially loses its tendency to adhere to the underlying felt surface and is easily removed from the felt. Papermaking pulp contains colloidal substances and synthetic anionic polymers added as part of the papermaking process, as well as natural anionic polymers, resins, surfactants, and organic acids (associated with the anionic waste of the paper industry). It is well known that it contains anionic polymers such as abietic acid (for example, abietic acid). It is believed that the cationic component used in accordance with the present invention interacts with the anionic polymer and colloidal particles to form a product that is easily removed from the felt. In either case, the process of the present invention greatly amplifies the tendency for sticky substances to pass through papermaking equipment rather than adhere to it.

The cationic polymer and surfactant of the present invention are applied in an aqueous solution directly to the processing equipment.

Treatment with surfactants alone cannot achieve the level of anti-precipitation effect obtained with the combinations of the present invention. Conversely,
Applying too much polymer to a papermaking felt without sufficient surfactant will also cause deposits of the polymer itself to build up, reducing the porosity of the felt (e.g. increasing tack). ) Water removal is substantially delayed or production is reduced. Therefore, the treatment amounts of polymer and activator should generally be tailored to the needs of the particular system being treated.

The aqueous solution containing the cationic polymer and active agent should preferably be substantially free of anionic polymers. These anionic materials include natural products such as wood lignin, chemical pulp by-products such as sodium lignin sulfonate, and synthetic materials such as polyacrylates.

The polymer and surfactant of the present invention are typically used as a liquid composition consisting of an aqueous solution of the polymer and/or surfactant. Polymer concentrations in the composition can range from relatively dilute concentrations with polymer concentrations suitable for continuous application to concentrations high at the solubility or gelling threshold of the polymer, but generally It is in a relatively high concentration that is suitable for shipping, transportation and handling.

In fact, the liquid composition can be further enriched with substances that increase the solubility of the polymer, making the composition even more concentrated. Such substances include, for example, alkoxyethanols, such as butoxycetanol. Aqueous compositions suitable for shipping, transportation and handling generally contain from 5 to 50% by weight of the active cationic polymer of the invention. The cationic surfactants of the present invention may be provided as a separate composition from the polymeric composition or may be applied to the felt separately (e.g. using a separate shear system) or mixed prior to application. However, it is preferred to prepare an aqueous composition comprising the cationic surfactant and the cationic polymer. Although other additives may be present in the compositions of the present invention, useful compositions include:
It includes a pitch formation inhibitor consisting essentially of a cationic surfactant and a cationic polymer as described above. Generally, aqueous compositions suitable for shipping, transportation and handling contain a total of 5 to 50% by weight of polymer and surfactant components.
Contains. The weight ratio of surfactant to polymer in such combination compositions generally ranges from about 50:1 to 1.
:50. The weight ratio of surfactant to polymer in the aqueous composition is preferably from about 10:l to about 1:l, especially if it may be present as an oil. and - most preferably about l=1 for intra-membrane applications. The surfactant may be present in excess (for example in a weight ratio of 1.1:l or more) if it is considered best suited solely as an oil.

Aqueous formulations believed to be particularly suitable for the sole use of the polymeric component in conjunction with further application of surfactants are available from Dearbon Chemical Co.
.

Ltd. (Ontario, Canada) and contains as active ingredients a polymerizable condensation product of formaldehyde, ammonium chloride, dicyandiamide, and formic acid in an amount of about 20,000 to 50% by weight.
It is believed to have a molecular weight of about 20,000 to 30,000; derived by the reaction of about 2% by weight epichlorohydrin with dimethylamine.
．． 000 polymer and about 8% by weight butoxycetanol. Small amounts of other substances, such as CI2, C8 and C as mentioned above, at about 0.4% as active ingredients.
, 6n-alkyl substituents are also present in the product, but their usefulness for individual use is not considered essential. In particular, it is believed that the relative amount of alkyldimethylammonium chloride is insufficient to activate the polymer precipitation prevention effect of the present invention. Another aqueous formulation believed to be particularly suitable for polymer individual addition is also available from Dearborn Chemical Co.

Ltd., and contains approximately 1% active ingredient.
It contains 7% by weight of poly(hydroxyalkylenedimethylammonium chloride) having a molecular weight of about 20,000. Another aqueous formulation considered to be particularly suitable for individual addition of the surfactants of the present invention is also available from Dearborn Chemical Co.

Ltd., which contains about 16% of the alkyldimethylbenzylammonium chloride surfactant described above as the active ingredient.

The optimum throughput will vary depending on papermaking factors such as the nature of the adhesive material and whether cleaning is to be done continuously or periodically. Even if the liquid composition of the present invention is made of a polymer at a relatively high concentration (for example, 50%), the liquid composition may be sprayed directly onto the felt in its original concentration (i.e., at 100% concentration as a liquid composition), for example, without diluting the liquid composition. can be used. However, especially for continuous processing,
Advantageously, the composition is diluted with clean fresh water or other aqueous liquids at the location where the treatment is carried out. Where water economy is required, dilution with high quality process water is sufficient.

An advantage of the present invention is that the polymer can be used at concentrations as low as 2 ppm and, particularly when continuous processing is carried out, further reduces the possibility of deposits derived from the applied cationic polymer component, as illustrated in the Examples below. This can be achieved in combination with a sufficient amount of surfactant to prevent the accumulation of. As used herein, continuous processing of the felt means that the felt is constantly processed at least once as it cycles between its sheet contact and return stages. It is most advantageous to carry out this steady state process early in the recovery phase. In doing so, the felt is in contact with the sheet to prevent sticky substances typically associated with recycled fibers from adhering to the felt, and any material deposited on the sheet is removed by the aqueous cleaning solution sprayed during the reversion phase. It can be easily washed away. In some cases, continuous treatment may not be carried out, but cyclic treatment with the cationic polymer and surfactant of the present invention may be performed.

For example, an aqueous solution of the polymer and surfactant may be sprayed onto a felt until the felt is sufficiently prepared, and then spraying is discontinued until preparation is needed to prevent deposit build-up on the next felt.

The processing operation will be explained more specifically by means of a model of a papermaking felt system, which is shown diagrammatically in a simplified form in FIGS. 1 and 2. The press felt system is represented as (lO) in Figure 1,
It consists of a top press felt (i2), a bottom press felt (i4), a final press bottom felt (i6), and a final press top felt (i8). The final press bottom felt (i6) is formed by a series of rollers (20), (
21), (22), (23), (24), (25) and (26), and are shown turning around the press rollers (29), the bottom press felt (i4) is shown passing around the series of rollers (30 ), (31), (32), (33), (
34), (35), and (36) and are shown turning around press rollers (37) and (38), with the top press felt (i2) passing through a series of rollers (40).
, (4I), (42), (43), (44) and (45
), and is shown turning around a press roller (47), and the final press top 7 elt is shown rotating around a press roller (49) and a series of rollers (60), (61),
It is shown going around (62) and (63). Both the top press felt (i2) and the bottom press felt (i4) are made of press rollers (37) and (4).
7). Bottom press felt (i4)
passes between press rollers (38) and (48),
And the final bottom press felt (i6) and the final breath top felt (i8) are connected to the press roller (29) and (
49). Top press felt (i2
), bottom press felt (i4,), final press bottom felt (i6) and final press top felt (i
The shower equipment for cleaning (8) is (50) and (5), respectively.
1), (52) and (53). press(
57) consists of press rollers (37) and (47), and press (58) consists of press rollers (38) and (48).
and the press (59) is a press roller (
It consists of (29) and (49).

The press felt system (i0) is shown in Figure 1 and (6
4), partially shown as Fourdrinier method (Fourdr
1nier wire-type) Receives sheet material from a paper machine. In Figure 1, the wire mesh (65) is designed to receive aqueous paper stock (slurry of type i) from a headbox (not shown in this case) which is raised and supplies the material to the production system. . The liquid is filtered through the pores in the wire mesh as it progresses through the sheet contacting stage and passes through the agglomerate breaking roller (66) and the couch roller (66).
67), which physically compresses the sheet material and releases it from the wire mesh (65). The wire mesh (65) then passes over a head roller (68) and returns to receive more paper stock.

This return typically involves a series of shower devices (
(not shown) and cleaning rollers as shown in (69). Additionally, a shower device (not shown) is provided to clean specific components of the papermaking system, such as the lump-breaking roller (66) or the head roller (68).

As shown in FIG. 1; during operation of the felt system, the sheet material is separated from the wire mesh (65) after the couch roller (67) and passes between the rollers (45) and (36) to form the top press felt. (i2) and bottom press felt (i
4) between the press rollers (37) and (47) of the press (57). The sheet material travels together with the bottom press felt (i4) towards the press (58) where the bottom press felt and press row-7
-(48),! 1: Press using a press roller (38). The sheet material is separated from the bottom press felt (i4) and goes to the press (59) where it is moved between the final press bottom felt (i6) and the final press top felt (i8) by the press rollers (59) of the press (59). 29) and (49).

The sheet material is separated from the final press felt and passes over support rollers (55) to subsequent processing equipment, such as a dryer (not shown). In the press felt system (lO) as shown in Fig. 1, the sheet contact stage of the top press felt (i2) consists of rollers (45
) or from a point between the roller (45) and the press (57) to a point behind the press (57).

On the other hand, the sheet contact phase of the bottom press felt (i4) continues from a point between the roller (36) and the press (57) to a point behind the press (58). The sheet contact stage of the final press bottom felt (i6) is carried out by a roller (
26) to a point behind the press (29),
The sheet contacting phase of the final press stop felt (i8) continues from a point between the roller (63) and the press (59) to a point behind the press (59).

It is clear that further equipment can be attached to the felt system 10, such as various presses, roller shower devices, guides, vacuum devices and tension adjustment devices. In particular, the drawing press (wr) that presses and removes moisture from the felt itself.
can be equipped with an inger press). Some of the devices further illustrated, such as a press (58)
and the final breath top felt (i8) can also be omitted from the felt system. It will further be apparent to those of ordinary skill in the art that felt systems can vary widely in the number of felts used and the design of the felt circulation system.

Felt systems are also used in fourdrinier paper making machines.
It is also used in papermaking processes that do not use a vire formal.

One such system is particularly useful for producing particularly thick sheet materials and uses a vat paper machine. The initial stage of the bat papermaking system is shown in Figure 2. The same family (70) includes a series of cylindrical wire meshes (i.e. batts), such as (72) and (73
), which are rotated to bring the cylindrical portion into contact with the pulp slurry and further rotated to deposit a web layer of paper onto the bottom couch felt (75). In addition to the bottom couch felt (75), the system (70) includes a first top couch felt (76) and a second top couch felt (77). Couch rollers (78) and (79) are provided to transfer the sheet material from batts (72) and (73), respectively, to pot couch felt (75). Potom Couchfelt (75) is Couch Roller (7)
8) and (79), roller (80), suction drum (81) and press roller (83), (84), (
85) and (86).

The first top couch felt has rollers (88), (8
9) and (90), and are shown running around the suction drum couch roller (91), and the second top couch felt is shown running around the press roller (93).
, (94), (95) and (96) and roller (9
7), (98), (99) and (i00). The bottom couch felt (75) and the first top couch felt (76) are the suction drum (81) and the suction drum couch roller (91).
The water is removed by vacuum from the felt and paper fiber webs. The bottom couch felt (75) and the second top couch felt (77) are moved by a press roller (8
3) and (93), press rollers (84) and (9
4), between press rollers (85) and (95), and between press rollers (86) and (96).

Press (i03) is press roller (83) and (93)
The press (i04) consists of a roller (84) and (
94), and the press (i05) is composed of a roller (85
) and (95), and the press (i06) consists of press rollers (86) and (86).

The shower devices for cleaning the bottom couch felt (75), the first top couch felt (76) and the second top couch felt (77) are (i07) and (
i08) and (i09).

During operation of the felting apparatus shown in FIG. Uchifelt (77)
Presses (i03), (i04), (i05) and (i06) are used between the two.

Then the sheet material is Couchfelt (75) and (
77) and sent to subsequent processing equipment, like the felt system (i0) shown in FIG. In the system shown in FIG. 2, the sheet contact stage of the bottom couch felt (75) continues from the bat (72) to just after the press roller (86), and the sheet contact phase of the first top couch felt continues from the bat (72) to immediately after the press roller (86). It is a couch roller, and the sheet contact state of the second top couch felt is approximately a roller (i0
0) to immediately after the press roller (96). In addition to the felt system (70), equipment such as bats, presses,
It is obvious that it can be equipped with roller shower equipment, guides, vacuum equipment and tension adjustment equipment. It is also possible to remove some of the equipment shown in the figures. It will be quite obvious to those of ordinary skill in the art that the number of felt devices used and the design of the felt circulation system can be varied.

The felt device (i2) of the system explained in FIGS. 1 and 2, (
i4), (i6), (i8), (75), (76) and (77) each of which, according to the present invention, comprises adding an aqueous solution of a suitable cationic polymer and a surfactant to its reversion stage (i.e. felting). The felt can be applied to the felt and processed continuously from the point where it leaves contact with the sheet material to the point where it comes into contact with the sheet material again).

Preferably, the solution is applied to the felt early in the reversion phase so that the deposited material can be transferred from the sheet material to the felt for rapid treatment. However, processing locations are often limited depending on the design of the felt system. Therefore, (50), (51), (52) in FIGS. 1 and 2,
Shower devices such as those shown in (53), (i07), (i0g) and (i09) can be used for treatment purposes. If the concentration of the working solution is higher than that required for continuous processing, application can be interrupted and resumed as necessary. For example, (50), (51), (5
2), (53), (i07), (i08) and (i09
) When applying the solution using a shower device, the device can be moved intermittently and then stopped according to the needs of the felt system. Devices other than felt can be similarly treated in a manner appropriate to each process operation.

In typical papermaking processes, especially those that use significant amounts of recycled fiber, the cationic polymer is generally at least about 0.002 g/min if continuous processing is employed.
When coating is carried out intermittently at a rate of 7 g/m"-min (hereinafter expressed in units of g/m"-min), preferably 0.018/m"-min or more, the coating period is Approximately 0.02 g/m2-m1n or more is applied in between. Preferably a coating rate of 0.5 g/m''-min or less is used to minimize the possibility of felt clogging.

In this way, on standard paper machines with felt widths of 2 to 7 ms and lengths of 10 to 40 m, the coating rate is usually about 0.02 to 20 g/m'w of polymer.
in, more typically about 0.05 to 12.5
g/m"-min. One technique is to first apply at least 1 g/m"-win and do not apply until the felt is conditioned. Once the felt has been conditioned, the rate of maintenance polymer application can be reduced, or the application can be interrupted periodically as described above. It is important that the surfactant is applied to the felt at a rate effective to prevent the build-up of deposits derived from the applied polymer and to prevent clogging of the pores of the felt. The weight ratio of surfactant to polymer is therefore generally kept between 50:1 and 1:50. To provide a sufficient amount of surfactant to prevent the buildup of precipitates, preferably derived from the polymer, and to protect against small amounts of contaminants and oils associated with the pulp.
The weight ratio of surfactant to polymer is about 1=1 or greater, and the weight ratio of surfactant to polymer is preferably about 10:1 or less to avoid using an excessive amount of surfactant. Make it. Most preferably the ratio is about 1:l. In all cases, it is preferred to use the surfactant at a concentration of at least about 1 ppm. Other equipment, such as wire mesh, screens, filters,
roller and suction box, and metal, granite, rubber,
and ceramics can also be advantageously treated according to the invention. However, the present invention is particularly useful for treating felts and similar equipment components having water suction pores (i.e., relatively fine pores) in which deposits substantially derived from polymers are susceptible to undesirably accumulating. Other devices that are useful, in contrast, such as metal and plastic screens, have relatively large pores that allow water to pass through and drain away in such amounts that deposits build up can cause undesirable problems. I can't imagine that happening.

In all cases, the concentration of cationic polymer in the aqueous solution ultimately applied to felt or other papermaking equipment should be at least about 0.0002% by weight. Continuous treatment of the felt with the felt shower system of the present invention, preferably to improve uniform distribution of the polymer,
from about 0.0002% to about 0% by weight of cationic polymer
．． This is carried out using an aqueous shower solution containing 0.02% by weight.

The practice of the present invention will become clearer from the following examples, but the present invention is not limited thereto.

Example ■ The test in this example was conducted using a Fourdrinier method.
ireformer) on a paper machine. The paper making machine is
Top press felt (i2), bottom press felt (i4), final 1-tube press felt (
i8), and a first top press felt, a first bottom press felt, a second top press felt, and a second bottom press felt, each similar to the final bottom press 7 elt (i6). Each felt device is equipped with a shower device. The first press felt receives sheet material from a Fourdrinier in a location generally similar to the apparatus (64) shown in Figure 1 and contains approximately 20% secondary (recirculated) fibers and approximately 80% hardwood fibers. A corrugated board material was produced from a raw material containing new fibers. The sheet-like material formed on the wire mesh is separated from the wire mesh and pressed into the press (57) in FIG.
to a first press somewhat similar to , where it is pressed between a first top press and a first bottom press. The sheets are sequentially separated from the 1 press felt and placed on the press (5) in Figure 1.
9), where it is pressed between a second top press felt and a second bottom press felt. In the paper machine, deposits had previously accumulated on the press felts, in particular on the second top press felt. Deposits include pitch and deposits from the pulp and recycled material, and come from the fibrous web that contacts the felt.

It has been a long-standing problem that the sheet gets damaged during the second press.
This happened once every 8 hour shift. Periodic shutdowns were required, thereby reducing seat damage. The second top press felt was approximately 20 feet in diameter and 61.5 feet long (ie, the treated area of the second top press felt was approximately 114.3 square meters).

A second top press felt according to the invention is applied to the shower water of an existing high-pressure shower system located at a position somewhat similar to the shower system (53) in FIG. and a C1,n-alkyl substituent, about 7.5% by weight of an alkyldimethylbenzylammonium chloride mixture having a molecular weight of about 20,000;
a polymer derived from dimethylamine and epichlorohydrin, and approximately 85% by weight of solvent (mainly water and small amounts of incidental materials, such as surfactants and/or ethanol that may be mixed in when mixing commercially available products of the polymer). ) are mixed and processed. The initial processing amount is approximately 0.6 g/min/m for each component, and the amount is
: reduced to about 0.02 to 0.03 g/min/m2.

Treatment efficacy was evaluated using a Huyck & Smlth porosity tester and measuring the number of breaks that occurred in the second press section.

The porosity of the felt was considered to be a measure of the water absorption capacity of the sheet. Felts with high porosity (ie, many open pores) were considered desirable for sheet dewatering.

The relative porosity of the second top press felt was measured using the Huyck & Smlth method during a 21 day test.

The method gives a high value of 100% for felts that are free or filled with pores, and a lower % for felts that are more porous (l(,S, number).Second top press The felt H, S, number is about 35 in the first few days of the exam.
% was maintained. The supply of processed products was interrupted for more than 24 hours. An increase in the H,S, count to approximately 50% was observed, which was due to the discontinuation of the process. The felt was cleaned and the test restarted. After restarting treatment, the number of HIS decreased to about 45% and remained at that value for several days. The supply amount of each processing component was reduced to about half due to pump malfunction, and the number of H, S, and 53
% was observed to increase. When the supply amount was returned to the previous level, the number of H and S was maintained at approximately 53% over the test period.

Porosity measurements during testing showed that the porosity of the felt could be maintained when the polymer and surfactant were applied according to the invention. Felt clogging increased by about 15 to 40% when the feed was interrupted. Furthermore, no sheet damage caused by the second top press felt occurred during the entire 30 day test period. Therefore, the treatment carried out according to the invention prevents sheet damage and equipment shutdown due to deposits in the second press, the treatment prevents the accumulation of deposits on the treated felt, and the treatment prevents the accumulation of deposits on the treated felt, and the It was concluded that clogging is greatly reduced.

Example ∎ The test in this example was conducted using a vat method.
ype) was carried out using a paper machine. The paper making machine produces a first bottom felt, a sac 1, which is somewhat similar to the bottom touch felt (75), the first top couch felt (76), and the second top couch felt (77) shown in FIG. a second drum couch felt, and a first top felt. The machine also has a second top felt, a second bottom seven elt, and a final felt, which are somewhat similar to the top press felt (i2), bottom press felt (i4), and final bottom press felt (i6) shown in Figure 1, respectively. (that is, there is no felt equivalent to the final top press felt). Each felting device is equipped with a shower device for cleaning. The paper making machine is equipped with seven cylindrical wire meshes (i.e., vats), which are arranged in an arrangement similar to the two vats (72) and (73) shown in FIG. Boards (eg straw board, tube stock, chipboard and chipboard partitions) are manufactured from 100% recycled raw materials.

The paper web formed on the cylindrical wire mesh leaves the cylindrical wire mesh and adheres to the underside of the first bottom felt. On the first bottom felt, the sheet is pressed between the first bottom felt and the suction drum couch felt and then passed between another press of approximately 4 m between the first bottom felt and the first top felt. do. The sheet leaves the first bottom felt and passes into a second press, somewhat similar to the press (57) shown in Figure 1, where it is pressed between a second top felt and a second bottom felt.

The sheet leaves the second press felt to the final seven elts where it is again pressed using an unfelted top press roller in a press somewhat similar to the press (59) shown in FIG.

Before testing the combination of the cationic polymer and cationic surfactant of the present invention, a first bottom felt, a sagging drum couch felt, a first top felt,
and the second Toppfeld in the conventional manner, C1□ as described above.
, a mixture of alkyldimethylbenzylammonium chlorides containing C14 and C,,n-alkyl substituents, FIG.
and the shower device (i07) shown in Figure 2, respectively.
, (i08), (i09), and (50) were pretreated using the shower equipment located at approximately the same location. In this test,
about 7.5% by weight of an alkyldimethylbenzylammonium chloride mixture and about 7.5% by weight of a mixture of alkyldimethylbenzylammonium chlorides having a molecular weight of about 2
0,000, a test product containing a polymer derived from dimethylamine and epichlorohydrin, and about 85% by weight of solvent (i.e., the same product used in Example I).
was diluted with water to give a surfactant and polymer concentration of approximately 2 J ppll each and applied to four felts at the same time. Once the addition of the polymer during the initial application period showed no clogging of the felt, the surfactant and polymer concentrations were each increased by 50% (ie, to a level of about 4 ppm). For the remainder of the exam,
Processing continued at this level. Each component was applied to each felt at a rate of approximately 1.5 g/min at the beginning of the test and at a rate of approximately 2.5 g/min for subsequent periods.
．． It was applied at a rate of 25 g/min. The widths of the first bottom felt, suction drum couch felt, first top felt, and second top felt are all I&7.75 feet, and the lengths are approximately 104 feet, 66 feet, and 427 (-1), respectively (i.e., the treated area is 74, respectively.
9m', 44.7m", 47.5m" and 30.
3m”).

During the test, the relative porosity (e.g. in Hg
) was measured across the width of the treated felt and at the same time was measured across the width of the second untreated bottom felt.

A significant increase in porosity under vacuum indicates that the felt has deteriorated. The results are shown in Tables ■ to ■.

Barley table■ Supply start 0.02 0.02 0.02 0.03 0.03 0.03 Supply stop 0.02 0.02 0.02 0.03 0.03 0.03 Supply start after pretreatment 0 .03 0.03 0.03 0.05 0.05 0.05 Supply stop 0.03 0.03 0.03 0.05 0.05 0.05 Table■ Table■ Supply start after pretreatment 0.03 0 .03 0.03 0.05 0.05 0.05 Supply stop 0.03 0.03 0.03 0.05 0.05 0.05 Supply start after pretreatment 0.05 0.05 0.05 0. 07 0.07 0.07 Stop of supply 0.05 0.05 0.05 0.07 0.07 0.07 Start of supply after pretreatment From Tables I to V, the cationic polymers were prepared according to the present invention. It is clear that the application to machine felt does not clog the felt or impair its porosity.

The press load (i.e. the pressure exerted by the press rollers of the six presses in the paper machine) remained unchanged during the test period, and the vacuum pressure (
i.e. suction to remove liquid from the felt), the first
Measurements were made at 13 points in the bottom felt, suction drum couch felt, first top felt, second top felt, and second bottom felt, and there was no change. Various properties of the sheet were also measured during the test and are summarized in Table ■.

Table 1 Sheet properties after pretreatment 69.6 5.9 552.4 80
2.9 Paper loading machine speed decrease before test start 15 66.9 4.6 557.3 8
20.450 66.9 3.2 538.
9 813.960 Increased raw material flow due to low moisture and caliber 100 Processing speed increase 215 69.6 4.5 550.2
823.8245 Processing stopped 265 71.4 4.9 551.7
822.6 Caliber 25 micron reading was discovered to be higher due to computer error.

The pH of the paper stock was maintained at about 6, and the vat temperature was about 38°C. The relationship of the original substance is about 0.37% for rose l-1 and 7,
It was about 0.40% for bats 2, 3, 4, 5 and 6.

The quality of the paper did not change during the test. Optimum moisture content is approximately 5%
The optimum caliber was thought to be approximately 800.

Table 1 clearly shows that a comfortable sheet moisture content was maintained during processing and that high speed operation could be maintained during and after conditioning the felt according to the invention.

EXAMPLE ■ The test of this example was equipped with a Fourdrinier with one pick-up (feed) felt, a series of presses, and a felt.
Yankee drying 11! (Yankee Drier). The same paper making machine usually has a large part (
A feedstock consisting of recycled pulp that has been deinked (i.e., about 40% to 100%) is processed. According to the prefectural police, the paper quality is p.
H6,0-6,5, the temperature is kept at about 40°C, and the production rate of the equipment is about 50 tons/day.

Prior to testing, the felts had to be washed 15 times or less per day with organic solvents and/or mixtures of organic solvents and detergents. Approximately 5 gallons per wash (i.e. 1
Approximately 75 gallons per day of solvent was used. Solvent washing was performed when necessary during operation, depending on the paper quality. A considerable amount of paper could not be sold because of its poor quality. Although deinking recirculation valves are relatively low cost and desirable in large quantities, they can create processability problems resulting in paper defects and/or breakage. As a practical matter, the usable ratio of deinked pulp was limited to approximately 60%.

Prior to testing, the pickup felt was replaced with a new one. Its width is about 2.7 meters and its length is 16.
It was 2 meters. Two lubricating shower devices were equipped on the pickup felt. This kind of felt is about 5
It showed a shelf life of 0 days.

A new shower system with a low pressure fan was installed for this test on the seat side of the felt, approximately 3 feet in front of the suction box. The shower device uses fresh water and has 13 nozzles, each with 2 U and S
, gallons per minute.

In testing, about 7.5% by weight of an alkyldimethylbenzylammonium chloride mixture, about 7.5% by weight of a polymer having a molecular weight of about 20,000, derived from dimethylamine and epichlorohydrin, and about 85% by weight of a polymer derived from dimethylamine and epichlorohydrin, weight%
A test product containing a solvent (i.e., the same product used in Examples I and ■) was diluted with fresh water for a new low-pressure shower;
Concentration of surfactant and polymer approximately 34 ppm each
and the surfactant and polymer are each 0.
-098/m''-min.

Although felt porosity was not measured on this paper machine for the first few hours of the test, it is clear that the frequency of solvent cleaning of the felt could be reduced. Furthermore, the content of deinked pulp in the raw material was increased to 100%. Solvent wash frequency is reduced to 5 to 12 times per day for 5 days;
The amount of solvent required per wash is reduced to approximately 3 gallons,
Solvent usage per day was reduced by about half (ie, less than about 36 gallons per day).

The low pressure shower device was then moved to a new location behind the suction box. Solvent cleaning frequency is further increased to 3 times per day.
It decreased in times. It is believed that this new shower location represents an improvement.

Furthermore, the raw materials were changed to 60% deinked pulp/40% new raw materials. With this variety, the frequency of solvent washing has been reduced to about once a day.

In summary, even from this preliminary test that lasted about 18 days,
Processing felt in accordance with the invention described herein facilitates the use of feedstocks containing high content of deinked pulp without unacceptable operational problems and provides the necessary solvent cleaning for efficient production. It is clear that this allows for a reduction in the number of washes and the amount of solvent used for washing, and reduces the number of inferior products, leading to significant cost savings.

The Examples describe various embodiments of the invention.

Other embodiments will be apparent to those skilled in the art from consideration of the specification or examples provided herein. It should be understood that further modifications and variations are possible without departing from the spirit and scope of the novel concept of the invention. Furthermore, it is to be understood that the invention is not limited to the specific formulations and embodiments described herein, but also includes modifications that fall within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a felting device of a paper machine that can be treated according to the invention. FIG. 2 is a schematic side view of a felting device in a vat forming a paper machine that can be processed according to the invention.

Claims (1)

[Claims] 1. A method for preventing the deposition of sticky substances on paper machine felt and other equipment parts used when processing pulp slurry into sheets, comprising: (a) at least about 2 ppm of cations in the equipment parts; (b) applying an aqueous solution containing at least one compound selected from the group consisting of water-soluble nonionic and cationic surfactants to the device component; A method for preventing precipitation, characterized in that it is applied in an amount effective to prevent the accumulation of precipitates derived from. 2. In claim 1, the cationic polymer is a dicyandiamide-formaldehyde condensation polymer optionally containing at least one compound selected from the group consisting of formic acid and ammonium salts as a polymerization reaction component. A precipitation prevention method characterized by: 3. A method for preventing precipitation according to claim 2, characterized in that the cationic polymer is derived from a reaction between formaldehyde, dicyandiamide, formic acid, and ammonium chloride. 4. In claim 1, the cationic polymer is obtained by the reaction of epihalohydrin with one or more amines or is derived from ethylenically unsaturated monomers containing quaternary ammonium groups. A precipitation prevention method characterized by: 5. The method for preventing precipitation according to claim 1, wherein the cationic polymer is protonated or contains a quaternary ammonium group. 6. Claim 1, characterized in that the cationic polymer is derived by reacting epihalohydrin with at least one compound selected from the group consisting of diethylamine, dimethylamine, and methylethylamine. Precipitation prevention method. 7. The method for preventing precipitation according to claim 6, characterized in that the cationic polymer is produced by a reaction between epichlorohydrin and dimethylamine. 8. A method for preventing precipitation according to claim 6, characterized in that the cationic polymer is produced by a reaction between epichlorohydrin and diethylamine. 9. Claim 1, wherein the concentration of the cationic polymer in the aqueous solution is about 0.0002 to 0.02.
% by weight and the weight ratio of the surfactant applied to the felt to the polymer applied to the felt is about 50:1.
A method for preventing precipitation, characterized in that the ratio is between 1:50 and 1:50. 10. In claim 1, the surfactant and the cationic polymer are applied to the paper machine felt at a return stage of the papermaking process in a weight ratio of about 50:1 to 1:50 in the same aqueous solution. A method for preventing deposit formation on paper machine felt that cycles between a sheet contact stage and a return stage, characterized in that: 11. The method for preventing precipitate formation according to claim 10, characterized in that the aqueous solution does not substantially contain an anionic polymer. 12. The method of claim 10, wherein the cationic polymer is applied at a rate of at least about 0.002 g/m^2-min. 13. A method for preventing deposit formation according to claim 10, characterized in that deposits are prevented from occurring on a felt that receives sheet material from a vat of a vat paper machine. 14. In claim 10, the fourdrinier method (Fo
1. A method for preventing precipitate formation, comprising preventing the formation of precipitates on a felt that receives sheet material from a wire gauze of a paper machine. 15. A method for preventing precipitate formation according to claim 10, characterized in that the felt is continuously treated with the aqueous solution. 16. A method of preventing precipitate formation according to claim 15, characterized in that the cationic polymer is applied at a rate of at least about 0.01 g/m^2-min. 17. The method for preventing precipitate formation according to claim 10, characterized in that the felt is intermittently treated with the aqueous solution. 18. Claim 17, wherein the cationic polymer is added at least 0.02 g/m during the period of application.
A method for preventing the formation of precipitates, characterized in that the method is applied at a rate of 2 minutes. 19. The method of claim 1, wherein at least about 10% of the papermaking pulp fibers are obtained from recycled materials. 20. The method of claim 1, wherein about 100% of the papermaking pulp fibers are obtained from recycled materials. 21. The method of preventing precipitation according to claim 1, wherein the paper pulp slurry is obtained from pine wood containing substantially about 2% by weight or more of resin. 22. A method for preventing precipitation according to claim 1, characterized in that the aqueous solution containing a surfactant contains at least 1 ppm of a surfactant. 23. In claim 1, the applied surfactant has a molecular weight of about 200 to 800, and has the following general formula ▲ mathematical formula, chemical formula, table, etc. ▼ where R independently of each other, selected from the group consisting of hydrogen, polyethylene oxide groups, polypropylene oxide groups, alkyl groups having about 1 to 22 carbon atoms, aryl groups, and aralkyl groups, in which at least one of the R groups has at least 8 carbon atoms; A method for preventing precipitation, characterized in that the surfactant is selected from surfactants having the following: an alkyl having a valence of 1/n, and X^- represents an anion or 1/n of an n^-valent anion. 24. A method for preventing precipitation according to claim 23, wherein at least one R group of the surfactant is an n^-alkyl group having about 12 to 16 carbon atoms. 25. In claim 24, two of the R groups of the surfactant are selected from methyl and ethyl, and 1
A precipitation prevention method characterized in that R groups are selected from ▲ has a mathematical formula, chemical formula, table, etc. ▼ and ▲ has a mathematical formula, chemical formula, table, etc. ▼. 26. The method for preventing precipitation according to claim 24, wherein the surfactant is an alkyldimethylammonium chloride or a mixture of alkyldimethylammonium chlorides. 27. A method for treating papermaking felt used to convert pulp slurry into sheets by circulating between the sheet contact stage and the return stage of the papermaking process to prevent the deposition of sticky hydrophobic substances on the felt. wherein the method provides, in the reversion step, a felt that: (i) has a molecular weight of from about 10,000 to about 300,000;
at least 2 ppm of a cationic polymer,
and (ii) has a molecular weight of 200 to 800 and has the following general formula ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ In the formula, R is independently from the group consisting of hydrogen, polyethylene oxide group, polypropylene oxide group, alkyl group having about 1 to 22 carbon atoms, aryl group, and aralkyl group a water-soluble surfactant selected from the group R, wherein at least one of the R groups is an alkyl having at least about 8 carbon atoms, and X^- represents an anion or 1/n of an n^-valent anion. the cationic polymer and the surfactant act on the hydrophobic substance at a rate of about 0.002 to 0.5 g/min/m^2 felt; A method for treating papermaking felt, characterized in that the substance is applied in such a way as to substantially eliminate the tendency of the substance to adhere to the felt. 28. In claim 27, the papermaking felt comprises a papermaking system in which at least about 10% is recycled fiber and 5% or more of which contains 2% or more resin by weight. A method for treating papermaking felt, characterized in that it is used in a system selected from a system obtained from wood. 29. Claim 27, wherein the felt is periodically treated at least once during cycling between the sheet contacting stage and the return stage, and the cationic polymer is applied at least about 0.01 g/min/m A method for treating papermaking felt, characterized in that it is applied at a ratio of ^2 felt. 30, Claim 27, wherein the aqueous solution is applied to the felt, and the cationic polymer is added to the felt at least about 0.02%.
g/min/m^2 felt until sufficient conditions are established, and discontinuing the application until corrective conditions are required to further prevent deposition on the felt. How to treat paper-making felt. 31. In the system, at least about 10% of the fibers are recycled fibers, the felt is circulated between a sheet contacting stage and a reversion stage, and the pulp slurry containing the anionic polymer and sticky material is processed into a sheet. A paper manufacturing system used for
In a method for preventing the deposition of sticky substances on papermaking felt, the method comprises: while the felt is in a reversion phase;
The felt is substantially free of anionic polymers and (i) has a molecular weight of about 10,000 with at least 2 ppm.
a cationic polymer of from about 300,000 to about 300,000;
(ii) It has a molecular weight of about 200 to 800, and has the following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ In the formula, R is independently hydrogen, a polyethylene oxide group, a polypropylene oxide group, about 1 to 22 selected from the group consisting of alkyl groups, aryl groups, and aralkyl groups having carbon atoms, at least one of the R groups is alkyl having at least about 8 carbon atoms, and X^- is an anion or n^ - 1/n of the valent anion, the surfactant has an effective amount to suppress the accumulation of precipitates derived from the cationic polymer. and the cationic polymer and surfactant are applied in a surfactant to polymer weight ratio of about 10:1 to about 1:1 to interact with the anionic polymer and the adhesive material. A method for preventing the precipitation of sticky substances, characterized in that the product forms a product that can be easily removed from felt. 32. Claim 31, wherein at least 70% of the fibers in the system are recycled fibers and the cationic polymer is added to the felt at least 0.002 g/min/m
A method for preventing the precipitation of adhesive substances characterized by applying the ratio of ^2 felt. 33. A composition for preventing the deposition of adhesive substances on paper felt, etc., which comprises (a) a cationic polymer, and (b) a molecular weight of about 200 to 800, and having the following general formula ▲ mathematical formula, chemical formula , tables, etc. ▼ In the formula, R is independently selected from the group consisting of hydrogen, polyethylene oxide group, polypropylene oxide group, alkyl group having about 1 to 22 carbon atoms, aryl group, and aralkyl group, a water-soluble surfactant having the following: at least one of the R groups is an alkyl having at least about 8 carbon atoms, and X^- represents an anion or 1/n of an n^-valent anion. , the weight ratio of surfactant to cationic polymer is from about 50:1 to about 1:1.
A composition characterized by: 34, Claim 33, wherein the cationic polymer has a molecular weight of about 10,000 to 3,000.0
00. 35. Claim 34, characterized in that the cationic polymer is a dicyandiamide-formaldehyde condensation polymer optionally containing at least one compound selected from the group consisting of formic acid and ammonium salts as a polymerization reactant. composition. 36. The composition of claim 34, wherein the cationic polymer is derived from the reaction between formaldehyde, dicyandiamide, formic acid, and ammonium chloride. 37. Claim 34, wherein the cationic polymer is obtained by reaction of an epihalohydrin with one or more amines or is derived from ethylenically unsaturated monomers containing quaternary ammonium groups. A composition characterized by: 38. The composition of claim 34, wherein the cationic polymer has a molecular weight of about 300,000 or less and is protonated or contains quaternary ammonium groups. thing. 39. Claim 34, characterized in that the cationic polymer is derived by reacting epihalohydrin with at least one compound selected from the group consisting of diethylamine, dimethylamine, and methylethylamine. Composition. 40. The composition of claim 34, wherein at least one of the R groups of the surfactant is an n^-alkyl group containing about 12 to 16 carbon atoms. 41. In claim 40, two of the R groups of the surfactant are selected from methyl and ethyl, and R
A composition characterized in that one of the groups is selected from ▲ has a mathematical formula, chemical formula, table, etc. ▼ and ▲ has a mathematical formula, chemical formula, table, etc. ▼. 42. The composition according to claim 40, wherein the surfactant is an alkyldimethylammonium chloride or a mixture of alkyldimethylammonium chlorides. 43. The composition of claim 42, wherein the cationic polymer is derived from dimethylamine and epichlorohydrin and has a molecular weight of about 20,000. 44. The composition of claim 34, wherein the composition is an aqueous solution containing a total of about 5 to 50% by weight of the polymer and the surfactant. 45. Claim 34, wherein the weight ratio of said surfactant to said cationic polymer is about 10:1 to 1.
:1. 46. The composition of claim 45, wherein the weight ratio of the surfactant to the cationic polymer is 1.1:1 or greater.