Toner powder is a powdery substance used in laser printers to fix images on paper.
As a common printing consumables, the quality of toner also determines the quality of printing to a certain extent.
So how to judge the quality of toner?
The comprehensive quality of toner mainly considers the following six factors: particle size and distribution, blackness, bottom ash, waste powder rate, resolution, and fixation.
1. Particle size and distribution
The particle size and distribution of toner directly affect the performance of toner. The particle size of good powder is generally in the range of 7-10 microns, and the distribution is also concentrated in these particles. The particle size of poor powder is generally 10-14 microns, and the distribution is also wide and not concentrated. Such a particle size will cause poor stability of toner, poor resolution, and unstable fixation.
2. Blackness
The printer is used for office use, and the average blackness value is generally around 1.4, which is most suitable. Of course, the higher the black value, the better. A certain amount of toner, at a certain average coverage, will have a relatively reduced number of printed pages, which will increase costs.
The calculation of the black value is that the black value tester first emits a certain number of strong light beams, which hit the pattern to be tested, and then reflects back to the black value tester, calculates the light beam absorbed by it, and then obtains the value through a fixed calculation program.
We generally have such a habit that the darker the printed words, the better the toner. But sometimes other factors of toner may also cause this illusion, such as poor fixation of toner, which is only adsorbed on the surface of the paper and not fully penetrated into the paper fiber. At this time, most of the toner particles on the surface of the paper are accumulated on the surface of the paper, and the absorption rate of light is very high, which gives people a very black feeling, but in fact, the melting point of this toner is high, and the printed words are not firm, which is not a good toner.
3. Bottom ash
The bottom ash value is the black value of the blank space without words in the printed sample tested by the black tester. It is also related to the degree of whiteness of the printing paper, that is, the bottom ash value of the same toner on different printing papers may not be the same.
Under normal circumstances, the bottom ash value of OEM toner is about 0.05~0.06. When it is greater than 0.06, the visual result will feel that the printed sample is a bit dirty. The reasons that affect the bottom ash value are mainly related to the conductive properties of the toner (abbreviated as electrical properties) and the particle size of the toner. The stronger the conductivity and the finer the particles, the easier it is to produce bottom ash.
Each model of printer generally requires different electrical properties of toner, which is also one of the reasons why we emphasize the use of special toner for special purposes. In addition, leakage caused by damage to the photosensitive layer on the surface of the photosensitive drum can also cause bottom ash.
4. Waste powder rate
The waste powder rate refers to the proportion of waste powder generated by a certain amount of toner in normal printing. The waste powder rate also directly affects the number of pages printed by the toner.
When toner is produced, various ingredients are added together in a certain proportion, fully stirred, and then ground after corresponding treatment. In this process, it is not guaranteed that the thickness of each toner particle and the proportion of its main ingredients, toner, iron powder, and resin, are the same, but can only be within a certain range. Beyond this range, the toner particle may become waste toner.
The waste toner rate of toner is between 5% and 7% and is within the normal range. The waste toner rate of poor toner is generally 10%-15% or even more.
5. Resolution
Resolution refers to the dots that can be printed per inch (DPI). The thickness of toner particles will directly affect the resolution. We can print some small characters to visually check whether they are blurred to judge the high and low resolution. We can also observe whether the printed lines have rough edges.
At present, the resolution of toner is mainly 300dpi, 600dpi, and 1200dip. The higher the resolution of the printer or copier, the higher the process requirements for toner particles.
6. Degree of fixation
Degree of fixation refers to the ability of toner attached to the surface of paper to penetrate into the paper fiber after melting.
Melting point is an important factor affecting the fixation of toner. When the melting point is too high, when the paper with toner particles passes through the fixing component, it fails to fully melt and penetrate into the paper fibers, and has passed through the fixing component. However, if the melting point is too low, the stability of the toner will become very poor.
When we test, we can touch the surface of the printed graphics with our hands to feel its roughness, and we can judge whether its fixation is good or bad. Generally speaking, the surface of the text printed by toner with poor fixation will be very rough.
Toner with a low melting point will be more firmly fixed, while toner with a high melting point will be more difficult to fix, and sometimes it will cause the fixing roller to stick. In general, the melting point of new low-temperature toner is controlled between 100 degrees and 140 degrees, which is adapted to the fixing temperature of the equipment.
Summary:
The above are the six determining factors of toner quality. In addition, we also need to consider other factors: toner consumption, compatibility, agglomeration temperature, layering, machine contamination, stability, etc.
Leave A Comment