The following indicators are often involved in the operation of toilet paper machine:
speed ratio
The ratio of the speed of the paper roller to the speed of the drying cylinder.
The method of measurement is to subtract the machine speed of the paper winder from the machine speed of the main machine, divide it by the machine speed of the main machine and multiply by the percentage.
Formula: speed ratio = (speed of dryer - speed of paper roller) / dryer speed *100%
Adjustment: too large speed ratio: can speed up or decrease the drying cylinder
Speed of paper roll cylinder;
Too small speed ratio: reducing the speed of the paper cylinder or accelerating the drying cylinder
Speed.
All of the above adjustments may readjust the material door of the slurry separation box to ensure the stability of the weight.
For example, the speed of drying cylinder of paper machine is 150m/min, and the speed of paper roller cylinder is 110m/min
So the speed ratio = (150-110) /150*100% = 26.7%
Width reading
Refers to the width required by the production plan unit original paper, that is, the width of the cross-section.
Method: measure with meter.
Adjustment: net cage.
If a 1575 paper machine can produce 1.75m of original paper, 1.75m is width reading.
ration
The paper quantity is also called gram weight, which refers to the gram weight of 1 square meter area paper, generally expressed in g/ square meters. In practice, there will be quantitative fluctuation:
(1) Vertical quantitative fluctuation of paper and its solution
Influence of pulp concentration: pulp forming refers to the pulp that enters the pulp pool after grinding and mixing.
Therefore, strengthen management, improve the operation technology level, master the concentration of slurry preparation, and control the pulp concentration within the specified range. Or in front of the paper machine, the pulp pool is equipped with a concentration automatic regulator to help the operator stabilize the slurry concentration.
Bad mixing in the slurry storage tank: the mixing of the slurry storage tank is poor, the slurry circulation is not smooth in the pool, and there is sedimentation. When the pulp surface in the tank drops and the concentration of the slurry in the tank increases continuously, the pulp concentration sent to the regulating box by the pump increases, which causes the paper to increase quantitatively.
The reason for the phenomenon of sedimentation and silting in the slurry storage tank is as follows:
① The structure of slurry pool is unreasonable, such as the slope of pool bottom is not enough, and the curvature radius of the joint part between the pool bottom and the pool wall is not suitable, that is, the slope is steep slowly
② The belt of the propeller in the slurry storage tank is loose and the speed is slow
terms of settlement:
① Using the opportunity of equipment overhaul, the unreasonable parts of slurry tank are improved
② Switch to a powerful propeller or increase the speed of the thruster
③ Tighten the belt properly or replace the new belt
Fluctuation of sizing on the net
The slurry quantity sent from the slurry tank to the pulp mixing box by the slurry pump is stable to the web part of the paper machine through the material gate. But there are also the following factors that cause quantitative changes.
(2) The liquid level in the inlet slurry tank of the second or third section of conical slag remover is unstable, which will cause quantitative fluctuation; the liquid level in the tail slag tank can be stabilized by installing floating ball valve to control the liquid level on the dilution pipe of the slurry tank.
(3) The liquid level in the inlet slurry tank of the second or third section of conical slag remover is unstable, which will cause quantitative fluctuation; the liquid level in the tail slag tank can be stabilized by installing floating ball valve to control the liquid level on the dilution pipe of the slurry tank.
(4) The automatic intermittent slag removal by rotor screen will cause the quantitative instantaneous fluctuation of paper. If the tail slurry of wing screen is changed to continuous slag discharging, the slurry loading can be relatively stable, but attention should be paid to prevent the slag discharge port from blocking.
(5) The fluctuation of circulation volume of white water causes the change of the concentration on the Internet.
(6) The change of paper machine speed
When the pulp quantity of the adjusting box is fixed, the paper machine speed changes will cause the paper weight increase and decrease quantitatively. The first is the fluctuation of the external power supply cycle, which causes the motor speed change. Therefore, it is required to maintain the stability of external power supply or install stable voltage equipment for the paper machine; secondly, some paper machines driven by belt, due to loose belt and slip, cause the speed change of paper machine, then tighten the belt or put some belt wax.
(7) The horizontal quantitative fluctuation of paper. There are generally several reasons:
A. The pressure at both ends of the roller is uneven, and the water quantity in the pressurized water bucket can be adjusted to be leveled by adjusting.
B. The cage is polluted, resulting in poor water filtration at one end and less slurry. Can be solved by cleaning and listening to the cage.
C. The upper mouth of the headbox is not parallel, and it can be solved by adjusting the upper lip.
The characteristics and treatment of paper diseases in toilet paper
1. Embossing:
The hole and embossing will be caused to different extent due to mechanical damage (including wool cloth), bad washing of mesh and cloth, poor sizing of slurry, poor quality of dispersant (including poor foaming of dispersant and quality of its own).
The apertures and embossing that appear periodically and regularly can be found out according to the interval distance, which is caused by one or more of the drying cylinder, copper mesh, wool cloth, idler and roller, and then improve them; irregular holes and embossing should be adjusted by finding the original size and dispersant.
A. When the blanket is not clean, use washing powder water to clean the cloth.
B. If the dispersant is too much (there is a long strip between), the dispersion dose can be reduced.
C. Adjust the blanket to balance.
2. Rough grain: the paper surface of the original paper is relatively rough.
A. Thick and bright strip: excessive amount of stripper / oil is used to debug with wet strength agent or other auxiliary agent. Or in the slurry pool into the slurry without stripping agent for adjustment.
B. No grain rough and many paper powder at the scraper: the scraper is not sharp or causes too long time, so it can be replaced.
C. Round bubble: caused by excessive steam pressure, moderate air pressure is lowered.
3. Hole: the original paper has holes, and the treatment method is as follows:
A. The holes caused by blanket are generally large, and only once when the blanket is running for a week. It can be improved by sewing or adjusting the position of blanket.
B. The hole caused by cage will appear once when the cage is running for a week, which can be improved by cleaning the cage.
C. The hole caused by the roller and roller will appear more complicated, which can be improved by repairing the roller surface.
D. The cylinder drying causes the hole to be known by observing the cylinder condition when the hole appears. It can be improved by grinding with gauze or by asking professional personnel to grind cylinder.
E. Water level, the whole paper has more holes. It can be solved by adjusting the water level of the headbox.
Hole and hole are the idea that the paper page is not completely penetrated. It is easy to see by naked eye under the reflection light. The small one is called the hole, and the big one is called the hole.
The paper surface mentioned above causes paper diseases such as light transmission point, curtain and embossing, and in case of serious cases, holes or holes are produced on the paper surface, except for this. There are also the following points: (1) pineye. A small hole. When the circular mesh machine produces thin sheet paper, it is often due to the bad size brooming, the fiber is thick and hard, the cutting is severe, and the larger the Internet hole is added, it is easy to produce pinholes. In the forward flow overflow type mesh groove, the distance between the spray plate and the net is too narrow, and the slurry speed is too fast, and the pinhole will also be produced. When using the air extraction circle network, the pinholes are produced when the pumping force is too high.
(2) A hole. The reasons for the hole breaking are not only the same as those of the eyes, but also: 1) the pulp rot group is crushed into a hole by the roller after it is connected to the Internet. 2) The roller is not round, the wet paper on the web is crushed, or the wet paper is not glued to the blanket by the sticky substance on the net. 3) A hole formed by a large mortar spot calender.
4. Impurity: the original paper has miscellaneous points, black spots and yellow points. Treatment method, cleaning tank, cleaning net tank, slurry box answer way, etc.
The source of dust is very wide, some from raw materials, some in the production process mixed into the slurry, some are paper after the formation of the cause. The measures to reduce dust on paper mainly include the following aspects: (1) do well in fiber raw materials and storage work, and do not mix harmful impurities. (2) strengthen the selection of raw materials and remove all kinds of impurities. (3) strengthen cleaning management and equipment maintenance, and prevent all kinds of oil and coal charcoal from entering the slurry. (4) in summer and autumn, the work of insect prevention in the workshop should be done well
5. Paper uniformity is not good
Uniformity refers to the uniformity of the distribution of fiber tissue in paper. The paper uniformity is not good, that is, the paper fiber is uneven, and the local or all of the paper is cloud shaped irregular fiber structure, called cloud flowers. The light cloud flowers on the paper have little influence on the quality of paper; if serious, the paper curtain will be formed, which will affect the paper strength and appearance quality, and even cause waste products. The reasons are as follows:
(1) The size concentration on the Internet is too large, the fiber is not well dispersed and flocculent.
(2) The size is too thick, the fiber is not uniform, and there are many long fibers.
(3) The pulp beating degree is low, the paper material is dehydrated quickly, which causes the overflow pulp quantity to be small and the pulp return concentration is high.
(4) The velocity of the online pulp is faster than the net speed, the slurry flow is unstable, the overflow slurry speed is higher than the network speed, or the online pulp speed is obviously slower than the network speed, and the elution causes the tissue irregularity of the paper fiber.
(5) The factors that cause the paper curtain also affect the paper evenness.
6. White dots, clouds
White spot, generally, can be solved by increasing the amount of dispersant, but there are exceptions. For example, if the waste paper containing wet strength agent is not fully dispersed, it may cause the paper white spot. The main reason for the cloud flower is that the moisture content of blanket is too large, which can be improved by slowing down the machine speed.
7. Insufficient tension
A. The low knock degree can improve the pulp beating degree or high knock solution.
B. Due to the ratio or quality of pulp fiber, investigate the ratio and quality of the slurry and make corresponding adjustment.
Common problems and solutions in network
All the rollers in the net must be processed and manufactured in strict accordance with the regulations, especially the rigidity and surface of the roller should be fully paid attention to, otherwise, the paper mesh will be wrinkled and drum wrapped in the production. The rollers of the mesh, especially the breast roller, are easy to adhere to fine fibers, so it is necessary to pay attention to cleaning to prevent the mesh from being deformed and corrugated due to the adhesion. Meanwhile, the scraper of the breast roller should be checked regularly to prevent the local feeding of slurry.
1. Net running
The position of guide roller has been adjusted to the end in the operation of copper mesh, but the copper mesh still moves to one side. Besides the operator is not familiar with the work, the main position of the roller is not correct. In the return operation of copper net, the position of a net roller is uneven, the voltage of the roller is uneven, and the position of the case roller is not correct. If copper or polyester net is always running to one side in operation, it can be found according to the above points and deal with the problems. If the above methods are still not solved, check whether the paper network joint has the phenomenon of staggered connection of the warp and wire.
2. Paste net
In the production, the cleaning methods can be determined for copper net, polyester net, and the property of paste net dirt. The cleaning can be done by pressure water washing, steam blowing, acid-base washing, and organic solvent washing. Please refer to the relevant monograph. When the polyester net is washed with pressure water, it can be determined according to the speed of paper locomotive. Low speed paper machine can be cleaned with low pressure water (gauge pressure) and auxiliary high-pressure water gun. At least two low-pressure water spray pipes are used to wash at ordinary times, the time of stopping and brushing or replacing spare parts, holding high-pressure water gun, and cleaning polyester forming net comprehensively at the speed of paper machine crawling, which can achieve better results.
Excessive water entering the headbox
1. when the water quantity is greater than the value of critical rate (avoiding flocculent) in the slurry tank or the value that can effectively filter water, it is excessive;
2. if the weir plate is not adjusted properly, it will weaken the forming - because excessive water flow causes too much head pressure, resulting in the imbalance of the ratio of slurry mesh speed;
3. if the design of slurry distribution system is unreasonable, a very serious groove may be formed in the headbox; if the water quantity is greater than the required value, the tendency of forming the trench flow will increase and produce streaks; in some places (such as: transverse sizing device), the slurry will form material channeling in the mesh; when the filling content of the online slurry is high, the gully flow will be greatly increased;
4. if there is too much water to be removed from the net, the paper sheet with rough, streaked or mesh marks will be generated;
5. the sluicing at the net will cause irregular fluctuation of the amplitude quantitative and can not be improved by adjusting the weir plate. Under such conditions, excessive water will aggravate the quantitative fluctuation;
6. through the precise use of the in-plane transverse beta table, these points can be tracked and the minimum optimal operation conditions of each paper type can be found;
Factors affecting the wrinkle of toilet paper
The wrinkle process is to scrape up the paper sheet attached to the cylinder surface with a scraper
If the adhesion between the paper page and the cylinder surface is infinite, the scraper will destroy the paper page and cannot wrinkle; if there is no adhesion, the paper sheet will not strongly conflict with the scraper, so as to avoid wrinkles.
Therefore, the main factors affecting the wrinkle process are the adhesion between the paper sheet and the drying cylinder and the proper installation of the scraper angle.
The appropriate adhesion and scraper angle should be that when the paper sheet conflicts with the scraper, the impact force and adhesion force of the scraper are balanced, and the paper sheet is folded and peeled away from the cylinder surface.
The adhesion is too large, although the wrinkles are fine, it is easy to break holes and even break the paper. On the contrary, the adhesion force is too small, and the scraper will peel away when touching, and the wrinkles will be slight and sparse.
For certain adhesion, adjusting the installation angle of scraper, that is, increasing the contact angle, can reduce the force of peeling the paper sheet, and improve the wrinkle frequency. On the contrary, the increasing of peel force will reduce the wrinkle frequency of paper pages. The installation angle of scraper is adjustable to adapt to different adhesion.
There are many factors affecting adhesion, such as high moisture when wrinkling, and the paper adhesion is large. This result can be caused by the slow evaporation of high beating degree or low evaporation at the cylinder surface. On the contrary, the moisture content is small when wrinkling. If the temperature of the cylinder surface is high and the beating degree is not low, the paper page will shrink much, and the adhesion with the cylinder surface will be reduced. From this perspective, the beating degree, the dry steam pressure, the quantitative fluctuation of the paper sheet, and even the cleanness of the blanket will affect the moisture content of the paper sheet and change the adhesion force.
Another important condition that affects adhesion is the surface state of the oven, such as the unclean surface of the oven, rust spots and the oxide layer on the surface of the cast iron cylinder, which will cause the paper page to have too much adhesion or uneven adhesion on the cylinder surface and affect wrinkle. Oil on the cylinder surface will cause the adhesion to decrease and not good.
For the case where the adhesion is not easy to be controlled by the production conditions, the auxiliary agent can also be used. For example, for the machine with low adhesion, a small amount of animal glue, oxidized starch, carboxymethylcellulose and other adhesives can be added to the paper or white water to improve the adhesion; for the machine with too high adhesion, a small amount of hydrophobic substances such as emulsified mineral oil and low molecular weight polyethylene can be added.
When the adhesion force of paper sheet changes, because the scraper has certain elasticity, the pressure of scraper line should be adjusted according to the adhesion force. That is, when the adhesion is large, the line pressure should be increased, otherwise, the paper clamping phenomenon will occur due to the scraper deformation, which will affect the wrinkle effect.
