The world of PC peripherals. Charge rollers (PCR) for laser printer cartridges. Problems and Solutions Contamination of PCR Contacts

One of the most important parts and at the same time the main consumable in a laser printer is its cartridge. Structurally, a laser printer cartridge is not such a simple device as it seems at first.

It usually consists of the following parts: photo roller, squeegee, magnetic roller, doctor blade and charge roller. In addition, not all cartridges are similar to each other, the fact is that Brother Samsung and Xerox consumables, unlike HP and Canon, use non-magnetic toner, and instead of a magnetic shaft, they are equipped with a rubber dosing shaft. It should also be added that the consumables of these three companies do not have a mining hopper and the dosage blade in them is made of metal.

Such a detail of cartridges as a squeegee is a metal frame, the edge of which is equipped with a special cleaning element with good elasticity. The main purpose of this part is to remove the toner that remains after transferring the image to a sheet of paper.

It should be noted that the squeegee has approximately the same service life as the photoconductor. Consequently, the squeegee is changed, as a rule, simultaneously with the photoshaft. This part has a felt toner seal, thanks to which the toner does not spill out of the waste bin.

Samsung cartridges deserve special attention. The fact is that, as a rule, there is no squeegee in them - instead of it, the so-called. primary charge roller, which is cleaned with a special brush.

Mining bunker

A part such as a waste toner box is a part of a cartridge designed to store waste toner. The latter gets there after cleaning from the photoconductor. At each refill, this container must be cleaned.

Photoreceptor

First you need to answer the following question: what is a photoconductor? A part of this type for cartridges is an ultra-sensitive "heart", which is a hollow cylinder, for the manufacture of which aluminum is used. From above this product is covered with a dielectric layer.

The photoreceptor can be located both in the printer itself and in its cartridge. On some devices, for example, on Brother equipment, the cartridge consists of two parts - toner and drums. One part contains the drum unit and the other part contains the toner. They change independently of each other - as they wear out.

The function of photodrums is as follows: after sending a sheet of paper for printing, the primary charge shaft, pressed against the photo shaft, transfers a charge with a minus sign to it and, at the same time, the ability to repel toner particles (powder in the cartridge). All those areas that were marked with a laser beam change their charge to positive, as a result of which they attract toner to themselves. Thus, the photo shaft forms a visible imprint of the image sent for printing.

At the finish, paper with toner adhering to its surface passes through an oven with high temperature indicators, which makes it possible to securely fix the toner on the sheet. In general, the photo shaft is the most capricious, but at the same time expensive detail laser printer of any model. As a rule, it should not be touched, as this can lead to a sharp deterioration in the quality of subsequent printing.

Corotron

The corotron is a thin wire to which a high voltage is applied. The purpose of this part is to transfer charge, resulting in the release of some ozone. With the help of a coronator, the surface of the photodrum is electrified, on the surface of which, in turn, a primary charge appears. Corotrons in the form of wire were used in almost all analog copiers, but now they are used much less often than before. Many manufacturers have switched to using charge rollers. But even today, wire coronators are installed in Brother printers and MFPs.

Infecting Roller

The charge shaft is a product consisting of a metal core enclosed in a rubber sheath. The main task of this part is to charge the photoconductor with particles with a negative charge. In addition, the primary charge roller in Samsung cartridges also serves to clean the photoconductors from all kinds of debris.

Photoshaft shutter

This part of the cartridge is for protection purposes so that the photoconductor inside the cartridge is not damaged during shipping. It protects it from dust and other negative factors. When the cartridge is installed in the printer, the shutter opens and allows the device's laser to charge the photoreceptor unhindered. Therefore, in order to gain access to the phototube when you remove the cartridge from the device, you must first move this protective shutter.

This element of the cartridge is designed to uniformly transfer toner microparticles to the surface of the photo shaft. The magnetic shaft is made, as a rule, in the form of a hollow tube containing a magnetic core. At the same time, in Samsung's consumables, the magnetic roller is called the "Developer Roller" and consists of a composition that resembles high-quality rubber in its properties. There is also a so-called. magnetic roller bushings, which are plastic bushings that set the gap between the magnetic roller and the photoreceptor.

Dosing blade

A part called the dispense blade is designed to create an even layer of toner on the magnetic roller. For its manufacture, metal or plastic is used, which has good elasticity. In addition to mechanical wear, the doctor blade is also susceptible to dirt. For this reason, it must be regularly and thoroughly cleaned of any foreign particles. In addition, the doctor blade has a smooth surface, which is necessary in order to ensure even distribution of the colorant.

Chip

Such an important part of a laser printer as a cartridge chip is able to read the number of printed sheets of paper. By itself, it is a small flash memory that is filled with information related to the operation of this consumable. For example, the chip contains information about serial number cartridge, as well as its type and date of manufacture. Thus, the chip on the cartridge is a kind of its "passport", especially since it can warn the user that the toner has run out.

And on Xerox printers and Samsung chip can even block further work device if the chip tells it that the toner has run out. And in order to refill a cartridge with such a chip, you will either need to change it or reflash the device itself. Users of HP and Canon printers are deprived of such problems - the device will tell them that the consumable has run out, but the chip will not stop the device.

Therefore, the device of the laser model printer cartridge is rather complicated. The main thing is not to forget that the photoconductor for the cartridge in this case is its main element, and therefore, when refilling, it should be handled with utmost care. An important difference between cartridges designed for a laser printer and an inkjet is that they are easier to refill and, if necessary, any part can be changed in them. And this, despite the fact that they are not intended by the manufacturer either for disassembly or for refueling. At the same time, with a competent and responsible approach, you can disassemble such a cartridge yourself, without resorting to the help of craftsmen.

Often the cause of cartridge failure is the wear of its main components - the photoreceptor drum, cleaning blade, magnetic roller, doctor blade and primary charge roller. The repair blade, contacts, pins, drum shutters and even the body itself are also the cause of malfunctions, this is to say, in general. And now, a little more in detail about each of the problems.

photoreceptor drum

Most often, the photo shaft is responsible for the breakdown of the cartridge. Toner is removed from it with a cleaning blade, and paper comes into contact with it during printing, which greatly affects the condition of the protective layer. Usually, if the photoreceptor drum is damaged during printing, the following symptoms appear:

1) A straight, very thin line indicates that the drum is scratched.

2) Groups of dots repeating throughout the entire page - this means the presence of a chip on the drum. The distance between the points corresponds to the circumference of the drum.

3) Gray toner spots on the page. The reason is the illuminated drum. The distance between the spots depends on the circumference of the drum.

4) Gray "tire tracks" either on the left or right side of the page. This is sometimes referred to as "sand scattered by the wind". This defect is caused by drum wear.

In all of the above cases, the drum should be replaced. There is no reliable way to repair a damaged phototube surface.

Cleaning blade (squeegee)

The cleaning blade removes toner residue from the surface of the photoreceptor drum.

Common signs of damage are:

1) A 3.2mm gray stripe across the entire page is caused by a cut or worn blade.

2) Gray page, toner sticking on the drum - caused by a very old, dull blade. These blades cannot be reused.

3) The cleaning blade "jumps" and therefore damages the drum. This means that not enough lubricant has been applied to the blade. If such a defect is found, the cleaning blade should be replaced. A poorly lubricated squeegee can also “stick” to the drum unit if not used for a while.

Magnetic roller (HP/Canon cartridges)

The magnetic roller is a specially coated aluminum roller that transfers toner from the toner supply compartment to the drum unit. The main failures occur due to scratches or wear.

1) Light print. The main reason for this defect is the wear of the magnetic shaft, because over time, the black conductive coating of the shaft wears off. If during a visual inspection of the shaft, you will notice a silver core, then the shaft is worn out and needs to be replaced. This problem mainly manifests itself when printing solid black areas. Plain text will print without noticeable defects.

2) White spots on the page may appear if there are scratches on the coating. Usually one or two scratches do not cause problems, but if there are more, then white spots appear when printing. This is especially noticeable if the scratches are concentrated in one specific place.

3) Intermittent Printing - This image transmission defect occurs when the magnetic roller contact is faulty. This is expressed in the printing of light or blank pages.

4) Large gray spots repeating with each revolution of the shaft - the cause of the problem is static discharge on the magnetic shaft shell. Static discharge can be caused by using a vacuum cleaner, for example, when refilling a cartridge when the humidity is below 40%. The only way to get rid of the charge is to wipe the shaft with a special cleaner.

Developer Roller (Samsung/Xerox Cartridges)

The developer roller is a roller consisting of a metal core on which pressed rubber with a conductive coating is put on. The toner is held onto the developer roller by a constant voltage from a high-voltage power source. No magnets are used to attract the toner in this case. The main failures are caused by scratches or wear on the conductive coating. All toner is abrasive, and since the pressure of the doctor blade presses it against the surface of the developer roller, it can cause wear on the developer roller.

Magnetic roll - usually there are problems
similar to problems with the magnetic shaft of HP / Canon cartridges (see the point above).

Primary charge shaft
The PCR has two functions. First, it places a constant charge on the surface of the drum, which allows the laser beam to create an image on it. Secondly, it places a variable charge on the photo roller, which helps to erase any residual charges remaining on the surface. Because of this dual role, there are many serious troubles with the primary charge shaft.

The following problems usually occur:
1) “Smearing” of the image - this defect manifests itself in the fact that an image printed, for example, at the top of the page, will be less vividly repeated below. This happens when the outer coating of the PCR is worn or dirty.

2) Vertical streaks - Caused by wear on the outer coating of the PCR.

3) Background - the reasons are similar to the previous two.

4) Horizontal stripes - this defect is caused by contamination of the contacts of the primary charge roller.

5) Black spots on the sheet - This problem is caused by scratches on the PCR. Spots appear after a distance equal to the circumference of the shaft.

6) Random dots on the page is a problem caused by too much powder on the PCR. There may be black dots in white areas and white dots in black areas.

Feed Roller (Samsung/Xerox Cartridges)
The toner, being mixed in the hopper with the help of a stirrer and receiving a triboelectric charge, is transferred to the toner supply shaft, which is energized. Further, due to the potential difference, the toner is transferred to the developer roller.

Doctor blade (HP/Canon cartridges)
The doctor blade controls the amount of toner on the magnetic roller. A worn blade will result in a light print, and a worn blade will create striations on the surface of the shaft, resulting in streaks (white voids) along the entire page.

Doctor blade (Samsung/Xerox cartridges)
The doctor blade controls the amount of toner on the developer roller. A worn blade will have the same effect as HP/Canon.

Recovery Blade
The recovery blade directs the toner removed from the drum to the waste toner box. A damaged blade will cause dots to appear throughout the page, and this defect will only get worse over time. This phenomenon is caused by spillage of toner. Most often, the cleaning blade is damaged (wrinkled) during refurbishment, the toner begins to accumulate on the surface of the blade and fall off from there. The longer the cartridge prints with a bent blade, the more toner accumulates on it and wakes up inside the cartridge. If a cartridge is returned to you with this problem, it should be carefully disassembled and the repair blade examined.

In laser printers, cartridges are an integral part of the image reproduction system. Almost 70% of all parts involved in creating a print are concentrated in a replaceable block filled with a coloring composition.

Structural elements of the cartridge

In general, a replaceable block is a sealed hopper with a compartment with a coloring composition - black, red, yellow or blue and uh electromechanical parts for creating an impression. There are two types of interchangeable devices for laser printers, with or without a built-in photoconductor. In the second case, the photosensitive shaft is installed in the printer body and the duration of the drum is significantly increased.

Rice. 1 Main parts laser cartridge

Details and structures of the toner hopper

In this compartment, in addition to the powder itself, there are elements for applying paint to the surface of the photocylinder. This:

magnetic roller;
knife for dosing the coloring composition;
a blade sealing the closure of the magnetic shaft and the housing;
activator to mix the toner and maintain the recommended density.

MagRoller(magnetic roller). It is made either from an aluminum tube with a protective coating and a magnetic rod inside, or from dense rubber with magnetic properties. The shaft is fastened to the housing walls with bushings that allow it to rotate freely.

The magnetic field, by attracting the metallic ink particles, provides the toner with a negative charge. Smooth surface of the shaft, the key to high-quality printing.

Doctor Blade(toner dispenser). Rectangular metal frame, the length of which corresponds to the dimensions of the magnetizing roller, equipped with a flexible plate. The plate material can be metal or polyurethane.

The purpose of the dispensing knife is to leave exactly as much toner on the magnetic roller as is necessary for printing at this stage. Blade wear affects the quality of impressions, the metal flexible plate can get scratched or chipped, polyurethane lasts longer, but still becomes thinner over time and doses worse. Regular cleaning of the metering plate or its timely replacement in case of severe wear will restore print quality.

Mag Roller Sealing Blade(sealing blade). It is made of flexible materials that do not injure the surface of the magnetic shaft. Most often, it is polyurethane.

After the transfer of the toner to the photoreceptor, that part of it that turned out to be unclaimed for developing the pattern remains on the surface of the magnetic roll. The sealing blade removes ink residue and leaves it in the toner compartment for reuse.

Toner Agitator Bar(frame-activator). Metal rotating frame. Prevents sticking and clumping of the coloring powder. The optimal density toner is easily and evenly attracted to the magnetic roller.

toner(toner). Fine powder of polymers or waxes. The color is imparted with appropriate pigments and treated with metal oxides to obtain magnetic properties.

Waste Toner Compartment

In this department, the exposure and development of the image takes place. Essential elements:

photoconductor;
coronator;
drum cleaning blade;
toner pickup blade.

organicPhoto Conductor (OPC) Dram(photodrum). The main element of image reproduction. It is made in the form of a hollow cylinder covered with an organic light-sensitive film or zinc oxide, which has a photoconductive effect.

A negatively charged photoreceptor is irradiated with a laser beam. The image is exposed by the programmer, in the areas reproducing the pattern, the laser neutralizes the negative charge. As a result of exposure, toner is attracted to these areas from the magnetic roller.

The life of the photosensitive film is short, so this part has to be changed frequently. Drums with a metal coating are more durable, but are also prone to flashing or deformation if carelessly used.

PrimaryCharge Roller ( primary charge shaft). It is made in the form of a shaft with an elastic coating, inside there is a conductor that passes a corona discharge.

The task of the coronator is to uniformly charge the surface of the photocylinder with a negative charge. Prior to work, the photoconductor has no polarity, that is, its surface is a dielectric. The passage of the discharge creates an electric field around the primary charge shaft, which, acting on the light-sensitive surface of the photoconductor, gives it a negative charge.

It is the work of the coronator that is accompanied by the release of ozone. After transferring the image to paper and cleaning the photodrum from the remnants of toner, the corotron again comes into action to remove the programmed image from the photocylinder.

wiperBlade(cleaning knife, squeegee). The knife is made in the form of a light metal plate with a glued blade made of rubber or polyurethane.

Not all of the toner gets on the sheet of paper, some of it remains on the photoconductor. Viper removes the remnants of the coloring composition in the mining compartment.

RecoveryBlade(pickup blade). Made from polyurethane. Designed to prevent the toner removed by the squeegee from getting on the paper.

Table. Resources of operation of cartridge assemblies (in cycles)

Cartridge	Primary charge shaft	photoconductor	Magnetic shaft

Principles of interaction of cartridge elements during printing

The cartridge is the first to start working when a “print” signal is given. The following actions take place.

Rice. 2 How a cartridge works in a laser printer

Processing the drum with a coronator (PCR) to give the surface of the cylinder a negative polarity.
Turn on the laser unit located in the printer case. The laser, controlled by the programmer, removes part of the charge from those points on the photoreactive surface of the cylinder where the image is programmed. This process is called exposure. The result is a complex of point charges with different levels of polarity. More strongly negatively charged points on the surface will repel like-charged toner. Accordingly, the exposed parts of the surface will attract the paint and the specified image will appear.
In parallel with the operation of the laser, the magnetic shaft is turned on. It draws the toner out of the hopper and gives it a negative polarity. The interaction of the fields of the magnetic shaft and the photodrum contributes to the transfer of the coloring powder to the light-sensitive surface. Turning off the device at this moment of work will allow you to consider the drawing applied to the photocylinder. This method is used to diagnose the wear of the photoconductor surface.
From the photoconductor, the image is transferred to a fed sheet of paper. Previously, the sheet is pulled through the rollers, giving it a positive polarity. The image formed by the negatively charged toner on the surface of the drum is deposited on the paper. To fix text and graphics, the paper sheet is pulled through heated rollers that melt the toner.
The next step is to clean the photocylinder from paint residues. The procedure is performed with a cleaning knife.
Next, the coronator captures the previously exposed image and prepares the photoconductor for the next printing step.

After restoring the original data, the process is repeated. Printing one sheet of A4 format, may include several successive text transfer processes.

Equipping laser cartridges with chips

At present, all manufacturers equip replaceable blocks for printers with programmable modules - CHIPs. The presence of such accessories in cartridges has both positive and negative sides.

What's Good About CHIPS

Record the amount of unused toner.
Determine the amount of used paint returned to the mining compartment.
Interact with the device's automatic calibration system. The system monitors color purity and print quality.
The optical system located in the cartridge writes data to the module.

Rice. 3 Color laser cartridges

What's wrong with CHIPs

Can be programmed for a certain number of printed sheets or even drum rotations.
After the message about the end of the toner, the relationship with the calibration system is broken. Prints appear to have an accompanying background and reduce color rendition in color printers.
Some modules may only work with certain printer and cartridge models. For example, in a color laser printer, you cannot change the chips on the cartridges, from red to green or black block.
Contactless radio chips are difficult to detect and replace.
After the end of the ink, the CHIP may block the operation of the printer.
Non-reprogrammable chips are quite expensive.

Customers should not sin on the greed of a company that refills cartridges. In addition to the cost of the toner, it is necessary to replace some parts that have undergone significant wear or deformation during extreme use. But, the most significant part of the cost of refilling is the programmable modules.

There are two main compartments in the cartridge - the waste compartment and the toner compartment.

The main components of the mining compartment:

1 - Organic Photo Conductor(OPC) Drum, Drum (OPC, Drum, Photoreceptor). It is an aluminum cylinder coated with an organic light-sensitive and photoconductive material that is able to preserve the image applied by a laser beam.

2 - Primary Charge Roller PCR (charge roller, primary charge roller). Provides uniform negative drum charge.

3 - Wiperblade Viper (Cleaning Blade, squeegee, cleaning blade). Cleans the drum of toner residue that has not been transferred to the paper. Structurally made in the form of a metal frame (Stamping) with a polyurethane plate (Blade) at the end.

4 - recovery blade. Covers the area between the drum and the mining bin. The Recovery Blade allows the toner remaining on the drum to enter the hopper, preventing the toner from leaking in the opposite direction (from the hopper to the paper).

TONER COMPARTMENT

The main components of the toner compartment:

1 - Magnetic Developer Roller Magnetic shaft (Mag Roller, Developer Roller). It is made in the form of a rotating metal tube, inside of which there is a fixed magnetic core. Toner is attracted to the magnetic roller, which, before being fed to the drum, acquires a negative charge under the action of a constant / alternating voltage.

2 - Doctor Blade Doctor (Metering Blade). Provides even distribution of a thin layer of toner on the magnetic roller. Structurally made in the form of a metal frame (Stamping) with a flexible plate (Blade) at the end.

3 - Mag Roller Sealing Blade A thin plate similar in function to the Recovery Blade. Covers the area between the magnetic roller and the toner supply compartment. The Mag Roller Sealing Blade allows the toner remaining on the magnetic roller to enter the compartment, preventing toner from leaking in the opposite direction (from the compartment to the outside).

4 - Toner Reservoir Toner hopper. Inside this hopper is the "working" toner, that is, the one that will be transferred to the paper during the printing process. In addition, the Toner Agitator Bar is built into the hopper - a wire frame designed to mix the toner.

5 - Seal Seal. In a new cartridge, the toner hopper is covered with a special seal that prevents toner from spilling during the transportation of the cartridge. This seal is removed prior to use.

The principle of laser printing

The figure below shows the cartridge in section. When you turn on the printer, all components of the cartridge begin to move - the cartridge is being prepared for printing. This process is similar to the printing process, but the laser beam is not applied to the drum and no image is formed. Then the components of the cartridge stop - the printer enters the Ready state (ready to print).

When you send an image to print, the following processes take place in the cartridge:

1. Drum charging

The PCR evenly coats the surface of the rotating drum with a negative charge.

2. Exposure

The negatively charged surface of the drum passes under the laser beam. The beam is focused on the drum and is activated only in those places where toner is to be applied in the future. Under the action of a laser, the photosensitive surface of the drum partially loses its negative charge. Thus, the laser inflicts on the drum an image prototype in the form of a weakened negative charge.

3. Applying toner

At this stage, the prototype image on the drum is converted into a visible toner image, which will then be transferred to paper. The toner located near the magnetic roller is attracted to its surface under the action of a permanent magnet, from which the core of the roller is made. When the magnetic shaft rotates, the toner on its surface passes through a narrow slot formed by the doctor and the shaft. As a result, the toner on the magnetic roller is electrified, acquiring a negative charge. Negatively charged toner sticks to areas of the drum that have been exposed to light. The doctor also ensures the uniformity of the toner layer on the magnetic roller.

4. Transferring toner to paper

By continuing to rotate, the drum, on which the toner image has already been applied, is in contact with the paper. WITH reverse side paper is in contact with the Transfer Roller that carries positive charge. As a result, negatively charged toner particles are attracted to the paper. It turns out the image “poured” with toner on paper.

5. Pinning an image

The paper with the "poured" toner image moves further to the fusing mechanism. This mechanism consists of two adjoining shafts between which the paper passes. The lower shaft (Lower Pressure Roller) presses the paper against the upper shaft (Upper Fuser Roller). The top roller is heated, and upon contact with it, the toner particles are melted and baked onto the paper.

6. Drum cleaning

Some of the toner does not transfer to the paper and remains on the drum. The drum must be cleaned of toner residue. This function is performed by the viper. All the toner remaining on the drum is scraped off by the wiper into the waste bin. At the same time, Recovery closes the area between the drum and waste bin, preventing toner from spilling onto the paper.

7. "Erasing" an image

At this stage, the prototype of the image applied by the laser beam is “erased” from the surface of the drum. PCR uniformly covers the surface of the drum with a negative charge, restoring the charge in those places where it was reduced by the laser. Any of the known cartridges includes several different blades, each of which performs an important and desired function. The cleaning of the photoconductor, the dosing of the toner, the sealing of the cartridge bins depend on the blades. During operation, any defect in any of the blades, whether it be the OPC Cleaning Squeegee Blade, Toner Dispense Blade, or Magnetic Roll Sealing Blade, can damage the cartridge.

Image drum cleaning blade (Wiper blade)

The cleaning blade is used to clean the drum unit of residual toner that has not been transferred to the paper during the image transfer process. The surface quality of the cleaning blade, the sharpness of the edges and exact dimensions, are very important for normal operation cartridge.

Toner dispensing blade (Doctor blade)

The polyurethane doctor blade regulates the amount of toner entering the magnetic roller and participates in the process of triboelectric charging of the toner to ensure accurate image transfer to the drum unit. The surface quality of the dispensing blade, hardness and dimensional accuracy are important for the normal operation of the cartridge.

Magnetic shaft sealing blade

The magnetic roller seal blade seals the toner hopper and prevents toner from spilling onto the paper. The magnetic roller sealing blade is easily damaged during cartridge remanufacturing and must be replaced in this case.

OPC Drum Sealing Blade

The drum seal blade is used as a seal between the OPC drum unit and the waste toner box to prevent toner from spilling onto the paper, creating a "splatter" effect when printing. The structure of the material, accurate and correct dimensions, as well as the quality of the blade point are important for the normal operation of the cartridge.

Primary Charge Roller (PCR)

The primary charge roller is used to charge the drum unit with a uniform negative charge, while erasing the old charge.

Magnetic Roll (MagRoll)

The pickup roller, together with the toner dispensing blade, charges the toner with a negative charge and transfers it to the photoconductor, thus playing an essential role in the imaging process. If the toner is unevenly charged or deposited unevenly on the surface of the magnetic roller, the result will be a light print and a change in print density. Constant wear of the magnetic roll is one of the biggest problems for remanufacturers. The magnetic roller is the basis for overall print quality and thus has a major impact on the overall performance of the cartridge.

When refilling and restoring laser printer cartridges, the most important step in the work is cleaning the cartridges from old toner and various other contaminants. The print quality of a refilled / remanufactured cartridge largely depends on how carefully and with the observance of technology the cleaning procedure was carried out. As in any business, a lot here depends on the tool used in the work, auxiliary equipment and materials. So let's discuss what needs to be done and what needs to be used to clean the cartridges.

Cleansing Basics

Today, there are hundreds of different cleaning products on the market, the manufacturers of which, without skimping on big words, promise to increase productivity, restore and increase the life of the components that they are designed to clean. However, studies conducted by laboratories have shown that, nevertheless, the use of such an agent as dry ionized filtered compressed air, which can be considered the main (basic) cleaning device, provides the best results.

In addition, studies, as well as thousands of practical experiments, have confirmed the opinion that the less you work on cartridge components, the better, since their “native” properties in this case do not undergo any kind of changes. A cartridge is a complex system of interconnected components, so it is important to maintain the original balance of the entire system and the properties of its individual components for as long as possible. An unsuccessful exposure or rough cleaning can backfire and adversely affect the entire system. The key to effective cleaning is preventing breakdowns and maintaining the balance of the entire system.

If you carry out regular procedures for cleaning the cartridge, and do it according to a well-established scheme (i.e., according to a proven technology), there is no need for extreme measures. Cleaning with dry ionized filtered compressed air is recommended for all types of cartridges, as does not have a chemical and constructive effect, unless, of course, the cleaning is carried out correctly. Cleaning agents can accumulate or leave a residue that is harmful to the cartridge as a whole and to its individual components. An example is the use of solvents to clean squeegees. Certain chemicals can leave a film on the squeegee, which can later be transferred to both the photoconductor and the PCR (Primary Charge Roller - often referred to as the charge corotron).

It is forbidden to use various cleaning, impregnating and covering agents in your work. Alcohol-based cleaners, for example, will damage the surface of the photoconductor, magnetic roller, cleaning blade, doctor blade, and the surface of some types of PCR (including OEM PCR). The individual components of the cartridge, having a direct relationship with the overall image formation process, can affect the quality of the print as a whole. Therefore, a change in the properties of the surfaces of individual components, due to chemical or mechanical effects, as a rule, significantly degrades the quality of subsequent printing.

Dry ionized compressed air

Compressed air is the most efficient and effective method cleaning all components of the cartridge, as requires a minimum of time due to the fact that you cover a larger area with a cleaning nozzle than with a vacuum cleaner (vacuum cleaning). In addition, it is possible to direct air into narrow openings, which is not possible with vacuum cleaning. Fragile parts and materials such as foam and felt are difficult to clean without harming them.

However, the mere presence of compressed air is not a sufficient condition for high-quality cleaning. Oil and water contained in the air streams can be transferred to other parts of the cartridge and can significantly increase the chance of printing problems. Static electricity can cause dust and toner to stick to the surface of the cartridge, from where they, being transferred from one part to another, will contaminate the entire cartridge, and it will be extremely problematic to remove this toner and dust. By using dry, ionized compressed air, coupled with a suitable dust control system, cleaning efficiency can be greatly improved. However, appropriate attachments and protective equipment must be used, as as recommended OSHA - Health and Safety Administration (Standard 29, CFR 1910.242, paragraphs a and b) when using compressed air, it is necessary to use personal protective equipment, in particular, nozzles that regulate air pressure up to 2 bar (maximum).

Isopropyl alcohol

When cleaning cartridges, alcohol can be both good and bad. Harmless alcohol can be considered for electrical contacts and the PCR saddle. But the following can be damaged by alcohol: magnetic roller, photoconductor, PCR roller, polyurethane and silicone, from which the dosing doctor blade and cleaning blade are made. Under no circumstances should alcohol be used to clean the listed components. It is necessary to avoid getting alcohol on all kinds of proplastic gaskets and seals, as well as on felt seals: alcohol can destroy the adhesive layer and the material will “move away” from the cartridge, thereby causing printing defects and toner spillage. For best results, only 91-99% isopropyl alcohol should be used. Alcohol with a high water content, i.e. alcohol solution with a low concentration of alcohol, requires much more time to spray and leaves the surface wet for a long time. Every time you use alcohol, you need to make sure that the surface of the parts of the cartridge is dry, and this must be done before pouring the toner and assembling the cartridge. 99% alcohol is purchased from distributors of chemical products.

A vacuum cleaner

The vacuum cleaner is an alternative to dry ionized compressed air. When cleaning the cartridge with a vacuum cleaner, it is necessary to use brush attachments and special attachments for cleaning narrow crevices. During cleaning, avoid touching the surface of the drum, magnetic roller, and PCR with the nozzles. But the vacuum cleaner has one significant drawback - when using it, it is easy to damage the fragile and sensitive components of the cartridge - various seals and gaskets, a returnable squeegee film, pieces of felt seals can be torn off and pushed out. In addition, when using a vacuum cleaner, the electrical contacts of the cartridge can also be damaged.

Applying too much pressure to the nozzle of the vacuum cleaner while cleaning the toner hopper through the hopper can easily bend the toner sensor rod or the axis of the toner mixing paddles. If the toner sensor rod (antenna) is bent away from the magnetic shaft, this will lead to a premature display of the low toner message (Low Toner).

Lint-free cloths and brushes

Soft, lint-free wipes and cotton lint-free brushes (tampons) are great for cleaning cartridge components. The so-called "Toner Wipes" are impregnated with mineral oil, which can contaminate cartridge components and should not be used to clean the inside of the cartridge. To avoid absorption of chemical cleaners, oil and cotton fibers into cartridge components, use only dry, non-cotton cloth. "Toner wipes" can only be used to clean the outer surfaces of a fully assembled cartridge. Lint-free materials are very good for cleaning with alcohol or applying a conductive lubricant, but should not be reused afterwards.

Lubricating powder «KYNAR»

Domestic specialists often call lubricating powders talc, i.e. "talc for photodrums". These lubricating powders are produced by various manufacturers, but one of the most famous is KYNAR lubricating powder.

KYNAR is a fluorinated polymer used to "lubricate" the cleaning squeegee in remanufactured cartridges. By dusting (sprinkling) the new drum unit and the new cleaning squeegee with lubricating powder before inserting them into the cartridge, you reduce the friction between them during the first rotations. Under no circumstances should lubricating powder be allowed to come into contact with the PCR. this may cause defects in the printed image. Even a small dot of lubricating powder on the surface of the PCR will not allow the photoconductor to be charged at that location, causing the “repeated black dots” defect to occur.

Primary charge roller - PCR

PCR is one of the most important elements affecting print quality. To clean it, you must use lint-free wipes moistened with water (after wetting, the wipes should be very well wrung out and should not leave drops of water on the wiped surface). Alcohol should not be used to clean the PCR as it will alcohol can damage the PCR roller coating. The determining factors in the use of PCR are its design and dimensions. Various cleaners and polishes (including those based on wax) can make the roller shine and clean, but do not improve its properties, and can even damage the roller and other cartridge components.

Organic photoconductors - OPC

Dry, ionized compressed air is the best cleaning tool for imaging drums, taking care not to touch the surface of the imaging drum with your fingers. Before installing the photoconductor in the cartridge, it must be placed in a place protected from light and carefully examine the surface for possible damage. Cleaning solutions and coatings can damage the image drum, and through the image drum and the PCR roller and cleaning doctor blade. Therefore, the use of various chemicals for cleaning is undesirable.

Cleaning squeegee and dosing squeegee

The surface of the cleaning blade is a cut with a manufacturing accuracy of less than 0.25 mm, so any abrasive action on the edge of the blade, such as contact with cleaning wipes, can dull the cut of the blade and lead to deterioration of its properties. Cleaning squeegees work best if they are not cleaned, polished or treated at all, as all this will not prolong their service life, but, on the contrary, will cause numerous problems (formation of a film on the surface of the photoconductor and on the surface of the PCR, an increase in the gap between the squeegee and the squeegee and, as a result, deterioration in the cleaning of the squeegee, inversion of the squeegee, etc.). The use of pastes, various coating agents for drums and all kinds of impregnating compounds can lead to the accumulation of these agents on the surface of the squeegee and the impossibility of removing them even with compressed air, i.e. to the impossibility of further use of the squeegee. Therefore, it is better not to use them.

The same applies to alcohol, which, by the way, is often included in the above funds. Numerous tests show that polyurethane squeegees absorb alcohol and become softer. As a result, any abrasive (cleaning) effect on the softened squeegee damages its working surface (cut). Alcohol absorbed into the squeegee can also affect the photoconductor, so you should avoid alcohol exposure to the squeegee and clean it only with dry compressed ionized air.

When installing a new squeegee, its surface must be treated either with a lubricating powder (talc), for example, KYNAR "ohm (see above), or with a high-quality toner, which will reduce the friction force between the squeegee and the photodrum. To lubricate the squeegee, it is necessary to immerse its working edge (cut ) into the lubricant and do not smear the lubricant on the surface of the doctor blade, so as not to create an abrasive effect.After installing the drum unit and doctor blade, rotate the drum (about 6 revolutions in the direction of normal rotation of the drum) until the lubricant settles into the waste toner box .

Magnetic shaft

It is best to use dry, ionized compressed air to clean the magnetic roller. Hold the shaft by the axle or use clean latex gloves. Touching the surface of the magnetic roller with your fingers can leave greasy spots on it, which may cause printing defects (background defects or blurry image defects that repeat with the circumference of the magnetic roller). It is not recommended to use chemical cleaners and coatings to clean the magnetic roller. Studies have shown that liquid cleaners used on magnetic rollers can cause poor print quality, and cleaner-treated magnetic rollers show noticeably poorer print quality than untreated magnetic rollers.

The presence of a solvent layer on the surface of the magnetic roller can cause the following image defects:

- pale print;

- blurry image all over the sheet;

- too bold characters;

- background image.

It may also cause the toner to spill out of the cartridge.

Electrical contacts

When refilling the cartridge, make sure that all electrical contacts are free of dirt and toner. Dirt on the cartridge contacts can cause the magnetic roller and photoconductor to charge poorly. Contact cleaning is best done with 91-99% isopropyl alcohol and a lint-free cloth. Then a thin layer of conductive grease must be applied to the places where it was originally applied by the manufacturer.

Conductive Cartridge Grease

A conductive lubricant is used in most cartridges to reduce friction at electrical contact points. When using conductive grease, the following basic rule must be followed: "Use grease only where it was originally applied by the manufacturer."

Lubricant application is different for each cartridge. For getting detailed information conductive grease, refer to cartridge refilling instructions, which are sometimes available from major compatible manufacturers. Supplies. When refilling the cartridge, it is necessary to remove the old lubricant with a brush or cloth that does not contain cotton fibers. Only then should a new lubricant be applied to the same surface. If a cartridge element is being replaced that has been lubricated, then a portion of the lubricant must be applied to the new element on the same surface as on the previous element.

Apply lubricant very carefully. Lubrication should be applied in a thin layer, the thickness of which is comparable to the thickness of a notebook sheet. A wooden brush tip can be used to apply a metered coat of lubricant. More lubricant can spread to other surfaces, i.e. stain adjacent parts of the cartridge, which will adversely affect print quality.

The conductive lubricant must be retained on the lubricated surface and must "work" during the full cycle of the cartridge, i.e. until the next reboot.

Despite the fact that the main purpose of the lubricant is to provide better conductivity, it, nevertheless, should not increase the friction force, i.e. its use should not increase the resistance of rubbing parts.

Adding a conductive lubricant in the hope of increasing the charge on the magnetic roller or photoconductor does not work, although there are known attempts to do so in the event of a defect such as dark printing. There is an opinion among a certain circle of specialists that if a “dark print” defect occurs, lubricating the contacts of the magnetic roller, PCR and the ground contact of the photoconductor will solve the problem and get rid of the dark background and dark image. But actually it is not.

As a conclusion to this review, we present to your attention pivot table(Table 1), which provides recommendations on the use of various means, materials and devices for cleaning various elements of laser printer cartridges.

Table 1. Recommendations for the use of tools and methods for cleaning cartridge elements

Cartridge component		Alternative cleaning method
photoconductorOPC	Dry ionized compressed filtered air	Not	Toner wipes, topcoats, impregnators, polishes, alcohol, solvents of any type
Primary charge shaft PCR		Compressed air	Toner wipes, topcoats, impregnators, polishes, alcohol, solvents of any type (including water-based)
Magnetic shaft	Compressed air	Not	Toner wipes, topcoats, impregnators, alcohol, solvents of any type
Cleaning squeegee ( wiperblade)	Compressed air	A lint-free cloth soaked in water and well wrung out
Dosing squeegee (Doctor Blade)	Compressed air	A lint-free cloth soaked in water and well wrung out	Toner wipes, pastes, alcohol-based top coats, alcohol, solvents of any type
Electrical contacts	Lint-free swab soaked in isopropyl alcohol	Not	Not
Gaskets and seals (foam and felt)	Compressed air	A vacuum cleaner	Alcohol and solvents of any type
Toner hopper	Compressed air	Vacuum cleaner (when using, be very careful not to damage the toner sensor rod)
Waste toner box	Compressed air	A vacuum cleaner	Cleaners and solvents
Bearings, bushings, bushings, gear wheels, etc.	Compressed air	Isopropyl alcohol-moistened lint-free swab or dry lint-free wipe	Cleaners and solvents (except alcohol)
Dosing squeegee holder	Compressed air	Dry lint-free cloth (press lightly when cleaning)	Coating compounds, cleaners, solvents, alcohol