1. The power supply must have the function of converting alternating current into direct current, and the voltage changes little when the load current changes in a wide range. 2, the output voltage should be stepless adjustment, to meet the needs of each process and different schemes. The voltage of ordinary power supply can be adjusted from 0 V to 30 V, and the highest voltage of high-power power supply can reach 50 V.
3. The power supply has strong self-adjustment function, and the output current should be automatically adjusted with the change of the contact area between the plating pen and the anode. 4. The power supply shall be equipped with a device for directly or indirectly measuring the coating thickness to display or control the coating thickness. 5. Overload protection device. When it is overloaded or short-circuited, it can quickly cut off the main circuit to protect the safety of equipment and personnel. 6. The power supply should be small in size, light in weight, reliable in operation, simple in operation and convenient in maintenance.
There are many manufacturers of brush plating power supply in China. As far as its control and output forms are concerned, there are generally three types: constant pressure type, constant flow type and pulse type. Its composition and working principle are basically the same. Generally, it is mainly composed of auxiliary circuits such as rectifier, ammeter and overload protection circuit. The electroplating pen consists of an anode and an electroplating pen holder, and the electroplating pen holder includes a conductive rod, a radiator, an insulating handle and the like. 1, anode classification and selection
Anodes can be divided into graphite anodes, platinum-iridium alloy anodes, stainless steel anodes, soluble anodes and anodes of other materials according to the materials used. In order to meet the needs of workpieces with different shapes and sizes, the anode can be made into various shapes such as cylinder, semicircle, crescent, flat plate, square strip and line. In practice, the shape and size of the anode should be determined according to the shape and size of the workpiece surface to be plated. For example, thin wire anodes are suitable for filling grooves and pits; Cylindrical anode is used for inner diameter or small plane, and semicircular anode is used for inner hole or plane; The excircle adopts crescent anode; Plane anode is used for plane or excircle.
For general small-area brush plating, it is best to design the anode working area as 1/5 ~ 1/3 of the plated area. However, due to the limitation of material size and strength, it is impossible to make a large-sized anode when painting in a large area, so we can only make a large-sized anode as much as possible according to the size of existing materials.
2, anode packaging and packaging materials
If it is not wrapped with a suitable material, the outer surface of the anode is not allowed to be directly used for brush plating. The function of anode package is to store plating solution, so as to prevent the anode from directly contacting the workpiece and causing short circuit, thus avoiding burning the workpiece. At the same time, it plays a mechanical filtering role for impurities such as graphite particles corroded on the anode surface.
Commonly used wrapping materials are mainly medical absorbent cotton, polyester cotton cover, or artificial wool cover. When wrapping, generally, a layer of absorbent cotton with appropriate thickness is wrapped on the anode surface first, and then polyester cotton sleeve or artificial wool sleeve is wrapped outside.
The anode package mainly wraps the surface in contact with the workpiece. The steps and methods of wrapping the cylindrical and flat anode are as follows: (1) Tear the absorbent cotton into thin slices (about 3 mm to 6 mm in thickness). (2) accord to that shape and size of the anode, the cotton is cut into strips with scissor.
(3) wrapping the cotton sliver along the outer surface of the anode. The ends of the cotton should be pulled into a wedge shape to make the cotton cover tight and uniform. (4) Choose a polyester-cotton cover with appropriate size and tie it tightly with rubber bands to improve the wear resistance of the cotton cover.
Anode coating thickness should be uniform and appropriate. When it is too thick, although a lot of plating solution is stored, the resistance is high and the deposition speed is slow. When it is too thin, less plating solution is stored, which is easy to wear through, causing local overheating or even short circuit of the workpiece and affecting the quality of the coating. The coating thickness is generally 5 mm ~ 15 mm (referring to the coating in virtual state).
3, the use and storage of electroplating pen
When brush plating, each solution must have one or several special plating pens. Before each electroplating pen is used, the name label of the electroplating solution used must be attached to the pen holder, and mixing is not allowed.
After use, the plating pens should be washed with clean water and stored separately, and they should not be mixed, especially those with copper plating and nickel plating, so as to avoid mutual pollution of plating solutions. Before using the electroplating pen next time, pay attention to check whether there is corrosion at the cable jack. If there is corrosion, remove it and clean it up.
Graphite anode will be corroded after long-term use, and the surface corrosion can be scraped off with tools such as file and scraper, and it can be used continuously. Excessive corrosion will be scrapped.
Once the anode sheath is worn, it should be replaced in time. Generally, the replaced cotton can't be used again. Cleaner cotton can be washed and dried with water and then used again.
When the used plating pen is not used for a long time, the anode, lock nut, conductive rod and radiator should be disassembled separately, cleaned and stored separately for reuse. 1, tire transfer
It is a device for clamping rotating parts. In order to meet the requirements of the relative movement speed of anode and cathode and reduce the labor intensity, it is an indispensable equipment for brush plating of shaft parts.
2. Liquid cups, plastic plates and extrusion bottles
The liquid cup is used to hold plating solution, the plastic tray is used to recover plating solution or wastewater, and the extrusion bottle is used to hold cleaning water or plating solution as a device for supplying plating solution.
3. Portable motor, various small grinding wheels, whetstone and scraper.
These are an indispensable set of tools for cleaning and shaping defects such as scratches, grooves and pits of workpieces and repairing coatings. 4, insulating tape, plastic sheeting
Insulating tape and plastic cloth are used to stick and cover the non-electroplating surface of the workpiece to prevent pollution and corrosion. 5. Scissors, rubber bands, needles and threads
Scissors are used to cut cotton and polyester cotton covers, rubber bands are used to tie packages, and needles and threads are used to sew packages.