BASIC RECHARGING PROCEDURES
Many of our customers believe remanufacturing only involves opening a cartridge, filling it with toner, closing it up and returning it to them. Although there are some rechargers who actually do it this way, this can cause many problems with your cartridge and resulting print quality.
The purpose of this report is to demonstrate the correct basic procedures in toner cartridge remanufacturing. Because there are many different types of cartridges, each requiring a different procedure, this report will cover the basic procedures that are common to most cartridges.
The following topics will be discussed in this report:
a. A basic understanding of the components
b. Understanding the components:
The main components that make a cartridge print are
- Magnetic Roller
- Charging assembly
- Doctor Blade
- Cleaning Blade
- Toner seal blade
f. Cleaning and replacement of components
k. Outer Housing Cleaning
There are many other components that make up a toner cartridge, but those listed above are the most important.
There are several types of toner used for recharging, but for the sake of time, we will discuss the most commonly used. The most common type of toner used is micro-fine particles of carbon and iron. Most printers are either 300 or 600 DPI (Dots Per Inch). The particles of toner for a 600 DPI printer will naturally be smaller than those in the 300 DPI printer toner. Because there are iron particles in the toner, it can be picked up with a magnet. The first component involved in transporting the toner is the magnetic roller. The toner is stored inside a toner hopper in the cartridge. The opening of the hopper is covered with a magnetic roller that picks up the toner to be transported to the drum. To prevent large uneven heaps of toner from being picked up at one time, the opening between the magnetic roller and the toner hopper is measured off with a component known as the "Doctor Blade". With the correct gapping on both sides of the Doctor Blade, just the right amount of toner is allowed to pass through the opening. A gap too narrow will result in too light a print, and a gap too wide will result in either excessive dark printing and/or leakage.
The Charge Assembly
There are two types of charge assemblies, also referred to as "Corona Assemblies". The newer type uses a charge roller named Scorotron, and the older types use a thin wire, not much thicker than a hair. The charge roller or wire is responsible for placing the charge on the drum. In laser printers, the static charge to the drum pulls the toner from the magnetic roller. The laser beam from the printer then hits the drum with an opposite charge, resulting in the image.
The drum is a cylinder with an organic or synthetic photo conductor coating that carries the image, still in powdered toner form, to the paper. Most drums will rotate 3 times to cover a single letter size page. This means that only 1/3 of the image can be placed on the drum at one time.
The Cleaning Blade
The cleaning blade is a polyurethane strip that rides against the length of the drum and covers the waste bin. As the drum rotates with the 1/3 of a page image on it, and places the image on the paper, some of the toner is still left on the drum and must be cleaned off before the next 1/3 of the image can be placed on the drum. If it is not cleaned off, the first 1/3 of the image will be repeated in a ghost-like background of the second 1/3 of the image, and the second 1/3 of the image will also be repeated in a ghost-like background of the third 1/3 of the image. The cleaning blade prevents this from happening. However, the edge of the cleaning blade must be precision sharp and smooth. The slightest little nick, scratch, or bow will allow unwanted image to pass through and may result in a ghosted repeated image, scratch marks, or lines on the page. As the cleaning blade scrapes the toner from the drum, it drops it into the waste bin. Because the toner in the waste bin has been charged, it can no longer be used.
The Toner seal Blade
The opening to the waste bin is lined with the cleaning blade on one side and the toner seal blade on the other side. The toner seal blade is a thin Mylar strip that also rests against the length of the drum. When the cartridge is in operation, the cleaning blade will be on top and the toner seal blade on the bottom. As the drum rotates and places the image on the page, the remaining image from the print first passes over the toner seal blade, then is scraped clean by the cleaning blade. The toner falls downward toward the toner seal blade, which scoops it into the waste bin (also referred to as the "Dust Bin"). If the toner seal blade is rippled, bowed, nicked or scratched, or missing, the toner that is scraped from the drum by the cleaning blade will fall onto the paper. The amount of damage to the toner seal blade will determine the amount of toner that will drop on to the page. It could be anything from light peppered dots to dark heaps or chunks.
Prior to recharging, a cartridge should be tested to determine the quality of the components. If the cartridge is the Corona Wire type, the charge wire should be cleaned before running the test. Several test sheets completely covered with text should be run. The first one or two should be discarded as "cleaning paper", and the next few should be examined for evenness of print on the sheet. If the cartridge has been milked dry, this may not be possible, and you may have to forego the pre-test. If a pre-test is possible, various types of marks on the page will determine which components are worn. For instance, anything that occurs 3 times down the page, whether it be fading or black marks, is usually the sign of a worn drum. 6 or more marks is usually the sign of a bad magnetic roller or charge roller. Hazy vertical lines are usually the sign of a dirty charge assembly or one that is shorting out. Straight vertical lines or repeated print are usually a sign of a worn wiper blade.
The cartridge should be broken down into it’s basic components: Cover; Toner Hopper; Dust Bin; Doctor Blade; Magnetic Roller; Corona Assembly; Drum; and Cleaning Blade. Any of these components that the pre-test indicated were worn out, should be marked for replacement. Further examination will determine excessive wear on each component, and those shown to be worn out should be marked for replacement. Where applicable, copy counters should be reset.
Any remaining toner in the hopper, and collected toner in the dust bin, should be dumped out. Because of the dusty nature of the toner, we wear a dust mask, protective clothing and plastic or rubber gloves, and dump inside a suction chamber that is filtered with a Hepa filter. Both the hopper and dust bin should be thoroughly vacuumed with a vacuum cleaner specially equipped with a hepa filter to prevent fine particles of toner from being scattered about the room. If the cleaning blade is not removed from the dust bin, care should be taken to avoid damaging it when dumping or vacuuming. All parts should then be blown off with an air gun attached to a compressor with at least 30 PSI of air pressure.
Cleaning and replacement of components
The toner seal blade should be checked for ripples. If it does not appear perfectly straight, it should be replaced. The cleaning blade should be checked for wear or damage, and replaced if necessary. The magnetic roller should be checked for gouges, and replaced if not in good condition. Charge rollers should be checked for nicks or surface pealing or flaking, and replaced as necessary.
The Cleaning Blade and Toner seal Blade:
Should be cleaned with water or peroxide, then wiped completely dry. To prevent dry rotting, you may coat the cleaning blade with a protectant. This does not work well on all types of cleaning blades, and may cause damage to some drums. The protectant should then be wiped clean and the wiper dusted with padding powder.
The Magnetic Roller
Should be wiped down with a non-abrasive sponge. Any toner that is embedded in the surface of the roller should be cleaned with 99% alcohol. Because the solvent will affect the output of the magnetic roller, the entire roller should be cleaned, rather than just the area of embedded toner. This will keep print uniform. If it becomes necessary to clean the magnetic roller with alcohol, toner may have to be rubbed into the surface with a sponge, during refilling. This process helps the magnetic roller to carry the toner more evenly, and prevents uneven printing.
The Charge Unit
The surface of the charge unit should first be cleaned with water or peroxide and wiped dry. Conductive cream should then be applied to keep the surface plyable without hindering the charge. The metal sawtooth ends should be cleaned with peroxide, then alcohol, and the cradle where the roller ends sit should also be cleaned with alcohol.
The Corona Wire
Should first be cleaned with peroxide, as should the rest of the corona assembly and all contacts. Then with 99% alcohol. The wire should then be burnished to remove any film left on by the alcohol, or unremoved oxide. The wire should then be tested for continuity by placing one end of a multitester on the contact, while running the other end slowly along the entire length of the wire. The meter should give a zero reading without fluctuating during this process. If the meter drops at any point, burnish that area of the corona wire again. If you continue to get fluctuations, replace the corona assembly or re-string the wire. Gold plated wire is the preferred method for re-stringing. It provides a better conductor, and is less susceptible to oxidation.
Should first be cleaned with water or peroxide. Any embedded toner should be removed with 99% alcohol. Depending upon the type of drum being cleaned, scuffs and minor scratches may sometimes be removed.
The seal prevents the toner from seeping from the hopper during transportation. Some cartridges are very tightly constructed and require no seal during transportation, but most do. A adhesive seal is placed between the hopper and the magnetic roller. This seal is then removed by the user prior to installation. After the seal is installed, the hopper should be checked for leaks by tapping it on a table at different angles, and slapping it on the sides. If there is any indication of leaking, it should be re-sealed until it no longer leaks. After sealing, since there is no way for toner to get to the magnetic roller until the seal is removed. Because you must post test the cartridge, it is a good idea to save a little toner from each fill, to use for priming the magnetic roller for post testing.
A pre-measured bottle of toner, and a funnel is the easiest method of filling. Different cartridges get different types and amounts of toner.
When the desired amount of toner is filled, the hopper cap should be immediately replaced, and the edges of the hopper cap should be blown off with compressed air in a hepa-filtered suction chamber. Be sure to save a little toner for priming the magnetic roller. The hopper should then be checked for leaks as described in the previous section. After tapping and slapping, turn the magnetic roller to see if any toner is on it. If your hopper is leak free, the magnet roller should be clean.
Using a gapping tool, gap the doctor blade evenly on both sides to ensure an even flow of toner to the magnetic roller in the correct thickness. This is done by loosening the screws on each end of the doctor blade, and moving the blade accordingly. Prime the magnetic roller by placing an even amount across the length of the roller. Vacuum the edges where the toner overlaps the felt pads on the ends of the magnetic roller. Rotate the magnetic roller, away from the doctor blade, until the heap of toner is all down under the doctor blade, and the roller is completely covered.
The cartridge should be reassembled in the reverse order that is was disassembled. However, before replacing the drum, it should be dusted lightly with padding powder, then placed on it’s axle over the cleaning blade. Once fastened, the drum should be rotated over the cleaning blade to ensure proper operation of the cleaning blade. The padding powder should be evenly cleaned off the drum as it is rotated. Once completely reassembled, the drum should be rotated to ensure that it is properly seated. If it is not, it will snap into place upon rotation.
The cartridge should now be tested to ensure proper operation. The first copy to be run is irrelevant because it is to be used as a cleaning paper.
The next copy should be an entire page of text. Many printers have a self-test function that will run a full text page. The text should be examined for even printing throughout the entire page coverage. Then it should be carefully examined under a magnifying glass for broken or distorted letters.
If everything checks out okay, the next copy to be run is a solid black page. If you are using a copier, this can be accomplished by opening the copyboard cover and running a copy. This is called a "Sky Copy" because you are making a copy of the sky above you. Because there is no paper in the copyboard, a solid black page will print. If you are using a laser printer, you will have to prepare a graphic page to be printed. Check the solid black page for even print throughout. Light spots indicate a problem. The different types of problems will be discussed in later reports.
Next run a solid white sheet. Examine it closely for marks of any kind. Any flaws in the drum, charge roller, or magnetic roller will show up here.
If the cartridge passes all of our rigorous tests, we clean all of the residual toner and finger marks from the entire casing with 99% alcohol. Be careful not to touch the drum through the shutter door when cleaning it, especially if the drum was recoated. The alcohol might dissolve the coating and cause major print defects.
The cartridge is then be packaged in an air-tight, static free, foil bag with black inner lining to prevent light from getting in. Drums are photosensitive and can be damaged with prolonged exposure to light.
The bag is then placed in a cartridge box with an insert to absorb shock. Because we ship the cartridges, we feel it is a good idea to further absorb the shock by floating the cartridge box inside Styrofoam peanuts in a larger container. "Floating" means cushioning all sides of the cartridge box with Styrofoam, so that no part of it touches the shipping container. This way, if it is dropped, or if something is dropped on it during shipment, the cartridge will remain undamaged.
After removing the seal and rotating the cartridge to loosen the toner, the corona wire, if your cartridge uses this type of technology, should be cleaned.