What is a magnetic roller?

The magnetic roller is a direct participant in the transfer process, and it plays two roles: it absorbs toner particles and charges the toner particles; the scratched area on the surface of the magnetic roller is not sticky to the powder, so that the relevant area of the corresponding printed product is also There will be blanks. In addition, the aging layer has appeared on the surface of the magnetic roller after printing for 3 cycles, which will also affect the charging effect of the magnetic roller to the toner, which directly affects the amount of toner transferred from the magnetic roller to the surface of the photosensitive drum. It directly affects the blackness of the printed product;

The developing magnetic roller is an important part of carrying toner. The permanent magnetic core does not rotate. Its function is to use magnetism to attract toner to the surface of the magnetic roller. The surface of the magnetic roller is sprayed with a rough graphite layer to form electrical cavities with the toner scraper to facilitate toner transfer. When the magnetic roller loaded with toner rotates out of the position of the scraper, the toner on the surface of the magnetic roller is not only charged, but due to the force of the magnetic field, it forms a "magnetic spike", that is, a "toner mist". The roller jacket applies a bias voltage to arrange the magnetic spikes in an orderly manner.

The toner transfer of the developing unit is completed in this way. When the toner is evenly stirred in the powder box by the agitator, the toner is carried by the doped carrier and absorbed by the permanent magnetic core in the magnetic roller to the outer surface of the magnetic roller. At this time, the toner does not show polarity. When the magnetic roller carries the toner and rotates and is tangent to the toner scraper and rubs with it, the toner is positively charged. Under the action of the toner scraper and the magnetic field, the toner forms a very thin and evenly distributed toner mist on the surface of the magnetic roller. The toner scraper also serves to limit the amount of toner, so that the toner does not absorb too much.

The so-called driving (slave) moving roller, as the name implies, is the drum-shaped power part and the basic element of the transmission part as the transmission mechanism. The difference is that the driving roller is generally the main transmission element in mechanical transmission, while the driven roller is the passive element in mechanical transmission. They are all basic parts that constitute the transmission power mechanism.

The structure of the driving (slave) roller is generally a roller-shaped composite manufactured product composed of two steel round shaft-shaped parts and an aluminum round tube-shaped part. Usually its basic structure features: 1 steel shaft at each end + 1 hollow three (four) vector tube; or 1 steel flange at each end + 1 middle aluminum tube. In addition to the first two types of assembled products, there is another type of drive shaft with a solid three-vector tube in the middle, and the two ends of the solid part are formed by cutting the remaining solid part of the shaft-shaped single finished product. That is, the shape characteristics of a single manufactured product are formed by different fractal surfaces on one material.

Generally, the requirements for driving (driven) roller components in the machinery industry have the following characteristics: good structural meshing of parts, smooth transmission, long service life, strong wear resistance, corrosion resistance, and high load impact resistance. And there are differences in the design of parts according to different conditions of use.

Structural features: The tube-shaped part and the shaft-shaped part on the entire roller are composed of different fractal surfaces on the same tube material. The processing technology of the single drive (slave) moving roller is relatively simple compared to the above two assembly drive (slave) moving rollers. The main difference is that it does not contain branch parts. Therefore, its engineering part number is the customer number. A common material shape is a three-vector tube with a solid central axis.

The heating shaft sleeve is also commonly known as the inner coating tube. It is a typical single finished product among the three major products made by our company. It is usually a seamless aluminum alloy sleeve used as a heating lamp for heat transfer and fusion of toner in the machine, that is, a heating roller. At the same time, it cooperates with the pressure rubber roller to complete the hot-press fixing and transfer of the toner on the printing paper.

As a single finished product, the heating shaft sleeve is not as complex as the combined finished product, but compared to the pipe parts produced and processed by our company, its basic shape is the most complicated and the processing technology requirements are relatively high. Such as the requirement of outer diameter difference. Therefore, its material series belong to the tube series, series number: 203. At the same time, we have made our own regulations on the project name and project name number that we use accordingly for its technological process.

Heating shaft sleeves are used as sleeves. Because of their corresponding models and models, even if they are used in different environments, their basic shapes are different. Some are necked pipes at both ends, and some are straight-through pipes with U-shaped grooves at the ends. ; Or with other functional shapes, such as waist holes. Therefore, to manufacture such pipe parts, the basic procedures and processes are more complicated than other pipe parts.

1. The driving (slave) moving roller is a component of the motive power in the mechanical transmission, that is, it cooperates with the motor to form the motive part of the system; it mainly plays the role of connecting the motor, transmitting power, and decelerating.

2. The magnetic roller is an important part for carrying toner; it has the function of transferring the powder to the imaging drum.

3. The heating shaft sleeve is a seamless aluminum alloy tube with heating lamp used as a heat transfer and melting toner, that is, a heating roller. At the same time, it cooperates with the pressure rubber roller to complete the hot-press fixing of the toner on the printing paper and the conveying of the printing paper.

The heating roller is made of seamless aluminum alloy tube, the thickness of the tube wall is between 1mm and 3mm, and the surface is coated with polytetrafluoroethylene. To prevent the melted toner from sticking to the roller during fixing. The PTFE coating on the surface of the heating roller will soften slightly at high temperatures. When the printing paper is stuck in the fixing device, do not use sharp hard objects (such as screwdrivers, cameras) to force it out. It will damage the surface coating of the heating roller and affect the integrity of the toner image after fixing.

The pressure rubber roller is also called the lower roller, and its function is to work with the heating roller to complete the hot-press fixing and transfer of the toner on the printing paper. The pressure is controlled by the support springs at both ends. The pressure roller is generally made of high-temperature resistant silicon rubber. The pressure roller in some laser printers is made of honeycomb heat-resistant sponge, and the outer surface is a layer of PTFE film. It is more conducive to the separation of the printing paper and the pressure rubber roller to prevent paper jams.

The other is "discharge rubber roller" transfer. The working principle of the two is the same. Different models have different transfer methods. The early production of laser printers mostly used the corona discharge transfer method. When the photosensitive drum carrying the toner image rotates to a position that is tangential to the transfer electrode or transfer rubber roller, a piece of printing paper is also fed between the two. At this time, the high voltage applied to the transfer electrode starts Discharge, while pushing the printing paper to the photosensitive drum, the toner image on the photosensitive drum will be attracted to the printing paper due to the transfer of the high-voltage electric field on the bottom of the printing paper to complete the secondary transfer of the toner image. The discharge polarity of the transfer electrode wire or transfer rubber roller is the same and negative, but this negative voltage is higher than the negative voltage in the exposure area of the photosensitive drum, so that while pushing the printing paper to the photosensitive drum, it also reduces The toner is attracted to the printing paper as much as possible. However, it should be noted that when the toner is transferred to the print paper, if the print paper is damp and the insulation performance is not good, it will affect the toner transfer efficiency, so there will be problems of image defect and poor printing quality of the hollow character chip.