In the mechanized production, all kinds of equipment and missing parts will be invalidated due to corrosion, wear and tear. Therefore, the loss of energy and materials caused by it is very alarming. According to rough statistics, the direct loss caused by mechanical wear and corrosion in China amounts to 40 billion yuan each year.
The Heidelberg multicolor machines commonly used in printing plants and the Manroland multicolor machines suffer from corrosion and crushing after the long-term operation of the impression cylinders, and the embossing cylinders are exposed to different degrees of corrosion. The original chromium layer is peeled off, resulting in reduced print quality. , Or even normal production, must choose the correct maintenance program, reliable, rapid, economic and convenient repair of corrosion, wear and tear of the impression cylinder. Brush plating technology is one of the effective methods to repair mechanical components. The use of thermal spray, brush plating technology to repair the drum, with a special nickel backing, brush nickel, silver, tungsten, cobalt ternary alloy coating, so that the repair layer and the base metal bonding firm, high hardness, ink resistance, wash your ears Corrosion.
First, the repair process scheme Brush plating process is a new technology of electroplating on-site electroplating, is a surface processing technology developed with the actual production needs, it is the principle of the use of electrochemical deposition, in the conductive surface of the workpiece The selected site, the use of the role of the electric field, the metal in the liquid migrated to the surface of the workpiece, the surface of the workpiece to obtain electrons, reduced to metal atoms, and the formation of a coating on the surface of the workpiece.
The brush plating process is an important means for the surface repair of mechanical parts because of its advantages such as light weight, high process recording speed, high deposition rate, high coating strength, high bonding strength, and wide application range. It is mainly used to repair the defect size of the workpiece and the geometric accuracy, strengthen the surface hardness of the workpiece, improve the service life, and improve the physical chemical properties of the workpiece surface. Therefore, it is feasible to use the brush plating technology to repair the corroded and worn roller surface of the offset printing press.
Second, the repair process flow 1) Brush Plating before the preparation of a 300A brush plated DC power supply, the use of insoluble anode material - nickel plate for the anode, the surface of the plastic coated rubber wool, and then cover the special knitted envelope.
2) Electricity net TGY-1, positive connection, working voltage 12-15V, relative movement speed 15m/min, time 10-20s, evenly spreading to the working surface water film, do not behave like waterdrop, use tap water to clean.
3) THY-2 activation -40s, tap water cleaning.
4) THY-3 activation is activated by activation fluid No. 3, reverse connection, working voltage 15-20V, relative motion speed 12m/min, activation time 40-50s, tap water cleaning.
5) The brush plating transition layer is primed with special nickel (TDY101). The special nickel solution is immersed in a plated pen, and then the current is applied. The voltage is 18V. The relative speed of cathode and anode is 15-20m/min. The brush bottom is 8-10s. Thickness 1-2μm, tap water rinse.
6) Brush plating work house uses fast nickel (TDY102) electroplating solution, no electricity to wipe the surface of the workpiece 8-10s, then the power is connected, the operating voltage is 18V, the relative movement speed is 12-18m/min, until the required thickness, use tap water to clean .
7) Brush Plating After Brush Plating Use 02# metallographic water sandpaper to polish the surface of the brush coating, dry the surface, and apply protective grease.
Third, economic benefits Because the printing press, especially Heidelberg, Manroland multi-color printing presses are large-scale equipment, dismantling overhaul cycle, long-term risk, high maintenance costs, the use of brush plating without dismantling or even without shutdown conditions It is significant that the technology is repaired. It can be produced normally during the day, brushed at night after shutdown, and repaired while producing; it only repairs damaged parts and has no influence on the other parts of the drum surface and the machine. Brush plating repair technology is of stable quality, and the repaired drum can be used normally for more than 10 years, which has significant economic benefits.
IV. Advantages of Brush Plating Repair Technology 1) The corrosion and wear surface of the offset printing cylinder is repaired by brush plating technology. Not only the dimensional accuracy is easy to control, but also the inspection time is shortened, which ensures the normal operation of the equipment and does not delay production.
2) The brush plating process is well-designed, and the plating is well-integrated with the base metal. After being repaired, it operates normally, is safe and reliable, and provides a reliable repair method for the regeneration of equipment and components.
3) The comprehensive economic benefits are obvious. It can be used as a reference for the recycling of similar parts and components. It is of practical significance for enterprises to save energy and reduce consumption, extend equipment life, and increase equipment operation rate.