JPH04130190A - Agent for cleaning and lubricating the surface of paper-making dryer - Google Patents

Abstract

PURPOSE:To obtain the title cleaning lubricant which can make the surface of a dryer clean to keep it always like a smooth mirror surface and thereby cam improve the thermal efficiency, paper quality, paper-making rate, and productivity by mixing an oily substance with specified surface active agents. CONSTITUTION:50-98 pts. wt. oily substance (e.g. natural wax or liquid paraffin) is mixed with 1-20 pts.wt. nonionic surface active agent and 1-20 pts.wt. cationic or amphoteric surfactant to give the title cleaning lubricant. By emulsifying this lubricant with water at an arbitrary ratio and using the emulsion, the surface of a dryer can be made clean and like a smooth mirror surface, and the state can be maintained. Therefore, it can improve the thermal efficiency, paper quality, paper-making rate, and productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning lubricant for use on the surface of a paper dryer.

[Conventional technology] Recently, paper mills have been increasingly using waste paper to save resources and reduce costs, while the need for more diverse use has led to an increase in the use of chemicals,
The number of coated products is increasing. Paper obtained through papermaking is dried in a drying process, and the function of the dryer used in this process is not only to simply heat and dry the paper, but also to impart smoothness and gloss to the paper. This is because the touch roll applies strong pressure to the paper, and when it dries, the smoothness of the dryer surface is transferred onto the paper. Therefore, it is extremely important to keep the dryer surface clean, smooth, and mirror-like.

Furthermore, by adding crepe to tissue paper, the aesthetic appearance, texture, and flexibility are improved, and the product value is also improved.

For this purpose, it is important to apply a fine and uniform crepe. Crepe is usually obtained by pressing a doctor blade against the dryer surface and peeling off the paper web from the dryer surface. Therefore, the size and quality of the crepe are determined by the optimal balance between adhesion and releasability between the paper web and the dryer surface. For this reason, the dryer surface must be clean and mirror-like.

However, under the present circumstances, paper webs on the surface of the dryer are pressed against the dryer and become embedded in the unevenness of the surface, resulting in scum. In addition, uneven contact with the surface of the doctor blade and the inability to follow the papermaking speed will make the roughness even more severe, and more and more residue will accumulate, turning into dirt and causing surface roughness. Furthermore, paper raw materials contain many impurities such as hot melt from old cardboard, clay, and resin in pulp, which fuse to the surface of the dryer due to heat, strip the short fibers from the paper, and adhere to the dryer. It becomes dirt. In addition, paper strength agents, sizing agents, etc. can also stain the dryer surface.

One method for removing dirt from the surface of such a paper dryer is to press a doctor blade against the dryer surface to scrape off the dirt accumulated on the surface. However, this ends up roughening the surface, which at best gets dirty quickly, and requires frequent replacement of the doctor blade, which takes a lot of time and effort.

Another method is to apply a blanket, felt, or the like impregnated with mineral oil such as kerosene or spindle oil, or vegetable oil such as rapeseed oil, by pressing it against the dryer surface. The purpose of this is to prevent the paper web from peeling off from the dryer surface and to prevent the short fibers of the paper web from being peeled off at that time. In other words, it seems that the paper is intended to improve its releasability by coating it with an oily substance. In that sense, there are cases in which a peeling agent is applied more aggressively or an eruption is performed. However, these merely form an oily film on a layer of dirt and grime, and do not directly clean the dryer surface. In addition, applying a release agent in this way will cause the paper to float from the dryer surface due to excessive release agent, reducing heat conduction and causing insufficient drying. This causes a decrease in the temperature. Furthermore, in severe cases, the excessive peeling effect may cause paper breakage, which may interrupt production. In other words, this method does not essentially solve the problem, and therefore requires frequent shutdowns of the equipment for cleaning and polishing of the dryer surface.

[Problems to be Solved by the Invention] In order to eliminate these problems, the present invention aims to clean the surface of the dryer by removing scum and dirt, which are the essential causes thereof, and to clean the surface of the dryer. Maintaining a smooth mirror surface at all times improves thermal efficiency,
The purpose is to improve paper quality, speed of paper making, and productivity.

[Means for Solving the Problems] The present invention is an emulsifiable dryer surface cleaning lubricant for papermaking that is obtained by adding a specific surfactant to an oily substance obtained by natural or synthetic methods.

That is, the present invention comprises (a) 50 to 98 parts by weight of an oily substance;
Preferably 75 to 96 parts by weight (b) 1 to 20 parts by weight, preferably 2 to 15 parts by weight of nonionic surfactant and (c
) A paper dryer surface cleaning lubricant comprising 1 to 20 parts by weight, preferably 2 to 10 parts by weight of a cationic surfactant or amphoteric surfactant.

One of the main effects of oily substances is to lubricate the contact area between the dryer surface and the doctor blade. Oiliness is one of the lubricating properties, and it forms an oil film at the contact area between metals, which reduces wear on the metals. Examples of such substances include naturally obtained animal and vegetable oils and fats, natural waxes, mineral oils such as spindle oil, machine oil, and motor oil obtained from petroleum, petroleum waxes such as microcrystalline wax and paraffin wax, and liquid paraffin. . Also included are synthetic lubricating oils such as synthetic esters, polyethylene glycol, polybutene, and silicone oils obtained by synthesis.

Another function of oil-based substances is cleaning. Some stains are highly oil-soluble and are easily dissolved by oil-based substances. Examples of such substances include solvents,
From a practical standpoint, it is desirable to have a high flash point. Such are hydrocarbons such as kerosene, petroleum spirits, mineral turpentine, halogenated hydrocarbons such as 1,1.1-)-lichloroethane, 2-ethylhexanol.

Examples include alcohols such as isotridecanol, low molecular weight polybutenes obtained by synthesis, and low molecular weight polyalkylene glycol ethers.

One of the functions of surfactants is to clean and remove debris and dirt from the surface of the dryer by reducing surface tension, penetrating and dispersing properties, and also to emulsify oily substances in water. As such a surfactant, a nonionic surfactant is used. For the purpose of the present invention, the HLB is preferably 1 to 40, particularly 6 to 20.

Furthermore, another effect of the surfactant is chemical or physical adsorption onto the metal surface of the dryer surface.

This adsorption is thought to be due to the orientation of the polar groups within the surfactant molecule, causing the polar groups to be adsorbed onto the metal surface, and the hydrocarbon groups, which are lipophilic groups, being oriented away from the metal surface.

In addition, there is also an adsorption effect on the cellulose fibers of paper.
It is thought that the polar groups in the surfactant molecules adsorb to the cellulose fibers, which are thought to have a negative charge, and orient the hydrocarbon groups further away from the paper. In this way, hydrocarbon groups are sandwiched between the metal surface of the dryer and the paper surface, and an oily substance is interposed therein. Examples of such surfactants include cationic surfactants and amphoteric surfactants.

As a cationic surfactant, long-chain alkyl (carbon number 10
~22) Trimethyl quaternary ammonium salt, long chain alkyl (C10-22) dimethylbenzyl quaternary ammonium salt, heterocyclic quaternary ammonium salt, benzethonium chloride, long chain alkyl (C10-22) pyridium salt, alkyl (C10-22) imidazolinium salts, dialkyl (C10-22) dimethyl quaternary ammonium salts, and the like.

As the amphoteric surfactant, alkyl (carbon number 10-22)
Dimethylcarboxybetaine, alkyl (carbon number 10~
22) Imidazolinium betaine, dialkyl (carbon number 10-22) methylcarboxybetaine, etc. can be mentioned.

The above-mentioned cationic surfactants or amphoteric surfactants preferably have high lipophilicity, especially those in which the alkyl group has 1 carbon number.
4 to 18 is desirable.

[Example] Next, the present invention will be explained with reference to an example. Parts are by weight.

Example 1 A dryer surface cleaning lubricant having the following composition was used.

Polybutene (average molecular weight 340) 88 parts Polyoxyethylene (3 mol) Coconut oil alkyl ether
8 parts polyoxyethylene (
8 moles) polyoxypropylene (11 moles) coconut oil alkyl ether 2 parts di-tallow alkyl betaine
Two copies were tested in the white paperboard manufacturing process.

Traditionally, this process involved applying oil to the surface of the dryer by pressing a blanket soaked with oil with a doctor blade.

However, dregs, pitch, etc. remained attached to the surface of the dryer and accumulated as dirt. As a result, the surface of the dryer became cloudy, and the areas where scum had adhered formed stripes. This tends to cause striped lines and fuzz on the paper. In addition, paper waste occurs due to oil stains when refueling the blanket, and a great deal of effort is required to replace the blanket, resulting in extremely low production efficiency in terms of time and economy.

An emulsified aqueous solution prepared by emulsifying 20 parts of this composition of the present invention with 1000 parts of water was sprayed into a dryer (
2 m width) at a rate of 1.0 liters per minute. Approximately 3
The stripes on the surface of the dryer began to disappear after spraying at zero tolerance, and the entire surface began to become cloudy and shiny, becoming mirror-like after about half a day of spraying. Accordingly, the stripes disappeared from the paper, the fuzz disappeared, and the paper quality improved. Also.

Improvements in drying efficiency were also observed, and the pressure of the steam used was reduced to 2°8.
Kg/cm" to 1.8 Kg/c+++2.

Example 2 A dryer surface cleaning lubricant having the following composition was used.

Liquid paraffin (viscosity 11 cst) 89 parts polyoxyethylene (3 mol) Coconut oil alkyl ether
7 parts Sorbitan monooleate 1 part Oleylimidacillin Quaternary ammonium chloride
3
This was tested in the interior liner manufacturing process.

Conventionally, in this process, a large amount of water, as much as 20 liters per minute, was sprayed to prevent scum from adhering. As a result, rust occurs on the dryer, the surface becomes rough, and the paper surface loses its luster.
In particular, paper breaks were occurring frequently due to poor drying of the ears.

In addition, the large amount of water sprayed resulted in large heat loss, resulting in poor production efficiency.

An emulsified aqueous solution prepared by emulsifying 5 parts of the above composition with 1000 parts of water was sprayed at a rate of 1.5 liters per minute into an operating dryer (3 m wide) using 30 spray nozzles.

After a while, the rust on the dryer surface is removed, and in its place an oil film is formed on the metal surface. Due to its lubricating effect, the dryer surface becomes smooth due to the "breaking-in" effect at the contact area with the doctor blade, resulting in a paper finish. Improved surface gloss. In addition, since the spraying of large amounts of water was stopped, drying performance was improved, and the amount of steam used could be reduced from 3.5 Kg/am2 to 2.3 Kg/cm, eliminating the problem of paper breakage.

Example 3 A dryer surface cleaning lubricant having the following composition was used.

Machine oil (viscosity 30 cst) 91 parts Polyoxyethylene (8 mol) Polypropylene (11 mol)
Coconut oil alkyl ether 3-part polyoxyethylene (8 mol) nonylphenyl ether
3 parts di-cured tallow alkyl dimethyl ammonium chloride 3 parts This was tested in the manufacturing process of dry crepe toilet paper. Conventionally, a doctor blade was used to remove scraps in this process, but the machine speed was too high and production was carried out with a large amount of scraps attached. Therefore, the adhesion between the paper and the surface of the Yankee dryer was poor, and when the paper web was peeled off from the surface of the dryer by the doctor blade, it became uneven, and a uniform crepe could not be obtained. In addition, the work environment was poor as paper dust was generated due to the peeling process.

Naturally, the thermal efficiency was also poor.

An emulsified aqueous solution prepared by emulsifying 1 part of the above composition with 1000 parts of water was sprayed at a rate of 2 liters per minute into a Yankee dryer (3 m wide) in operation using 30 spray nozzles. After about 1 hour of spraying, the adhering residue was removed and the surface of the Yankee Dryer began to become glossy, and the crepe became uniform and fine and extremely soft to the touch. At the same time, the drying efficiency improved by 10% per second, and the doctor blade replacement time could be extended from every 2 hours to every 8 hours.

Example 4 A dryer surface cleaning lubricant having the following composition was used.

Machine oil (viscosity 14 cst) 60 parts Polybutene (average molecular weight 1000) 30 parts Polyoxyethylene (8 mol) Polyoxypropylene (11 mol) Coconut oil alkyl ether 3 parts Ditallow alkyl dimethyl ammonium chloride 4 parts Dimethyl coconut oil alkyl betaine 3 parts This was tested in the tissue paper manufacturing process. Conventionally, in this process, a release agent for internal addition was added to the pulp slurry, but the release properties were uneven, making it difficult to form a uniform crepe, and a large amount of release agent for internal addition had to be used.

An emulsified aqueous solution prepared by emulsifying 1 part of this composition with 1000 parts of water was sprayed at a rate of 3 liters per minute into a running Yankee dryer (4 m wide) using 4 spray nozzles.

As a result, the crepe was uniform and fine, and had a very soft texture. The amount of the conventional internally added release agent used was 900 to 1000 kg on a monthly basis, whereas according to the present method, a monthly amount of 100 to 110 kg was sufficient.

Comparative Example 1 The following composition containing neither a cationic surfactant nor an amphoteric surfactant was used.

Liquid paraffin (viscosity 11 cst) 90 parts sorbitan monooleate 5 parts polyethylene glycol (molecular weight 600) monooleate
When 5 copies of this were tested in the same manner as in Example 2, dregs were partially attached to the surface of the dryer and glossy spots were generated on the finished paper surface. In addition, the doctor blade was worn out due to the adhesion of debris, and the time required to replace it was shortened from 8 hours to 3 hours.

Comparative Example 2 The following composition containing an anionic surfactant was used instead of a cationic surfactant or an amphoteric surfactant.

Machine oil (viscosity 15 cst) 86 parts Polyoxyethylene (8 mol) Polyoxypropylene (1
1 mol) Coconut oil alkyl ether 3 parts polyoxyethylene (3 mol) Coconut oil alkyl ether
8 parts Sodium dodecylbenzenesulfonate 3 parts This was tested in the same manner as in Example 3, but the surface of the Yankee dryer could not be kept sufficiently clean, the drying efficiency decreased, and the doctor blade was worn out due to adhesion of scum. It was hot and had to be replaced every 3 hours. As a result, the crepes were also uneven, and production efficiency was not improved.

[Effects of the invention] The paper dryer surface cleaning lubricant of the present invention emulsifies with water in any ratio, and by using this, the dryer surface becomes clean, smooth and mirror-like, and can maintain that state. . This improves drying efficiency and provides appropriate peelability from the dryer surface, which increases the surface gloss of the paper and creates a crepe that gives tissue paper a soft texture. Obtainable. It also improves thermal efficiency, increases papermaking speed,
Productivity can be significantly improved by reducing the frequency of polishing the dryer surface and replacing the doctor blade, reducing the amount of paper waste, and preventing the generation of paper dust.

Claims (1)

[Claims] 1. Paper dryer surface consisting of (a) 50 to 98 parts by weight of an oily substance, (b) 1 to 20 parts by weight of a nonionic surfactant, and (c) 1 to 20 parts by weight of a cationic surfactant or amphoteric surfactant. Cleaning lubricant.