To talk about the impact of electroplating equipment on the quality of plastic chrome plating layer?

Chromium plating is one of the main production units in plastic electroplating. The density and uniformity of the coating affect the quality of the products. Equipment, plating solution and process technology are the key links of the electroplating quality, and the quality of equipment operation and maintenance directly affects the realization of the process. In the long-term practice of electroplating production, according to the production field accumulated experience recorded some due to equipment or improper use affects production and electroplating process of typical fault cases of some fault, a chrome production line instrument, busbar, auxiliary anode analyzed for peer reference. For the convenience of analysis, in the fault analysis of this paper, it is assumed that the electroplating power supply, instrument body, the main body of the transmission bus, chrome plating process and the material of the plating solution, and the plastic electroplating electrode are all in good condition.

1 example of improper design of anode shape:
1) trouble phenomenon in the chromium plating production line for copper tube mould chrome plating. One end of the copper tube mold is irregular shape. In the chromium plating process, the mold is the cathode, the graphite is the anode. The process of plating test, appear crystallizer arc end local chromium layer is too thick or no local coating.

2) the failure cause analysis and elimination method of plating process personnel and equipment maintenance personnel from equipment, chromium plating process and plating solution formula, plastic electroplating electrode material and so on many aspects of debugging, all did not solve the problem. Through the comprehensive analysis of fault phenomenon, put forward the profiling anode made of graphite anode, the cathode surface of each part and the anode distance closer, to improve the uniformity of the surface current distribution on the cathode. A good solution to the problem of production. This process has been running for nearly twenty years, and the effect has been good.

2. Meter usage error

2.1 production examples 1

1) failure phenomenon of a plastic electroplating workshop production line overhaul, found in accordance with the provisions of the original process of DC current plating, the coating can not meet the requirements, resulting in product batch. Plating operator that "the same current, cathodic hydrogen evolution and anodic oxygen evolution than before the production line overhaul violent, feel the current larger repair before the same production and processing conditions is much bigger." But the DC current meter indicates the current is normal. Equipment and instruments, plating solution are normal.

2) fault cause analysis and elimination method with millivolt meter measured the shunt output voltage to 70mV, instrument for 6000A/75mV, conversion current 5600A. And the current value of the process is 2800A. At this point the production line rectifier power supply and plating bath side table are also indicated as 2800A. Thus determining the meter indication error. Check the line two series access shunt ammeter. This is the cause of the trouble. Change the two table for the parallel connection, troubleshooting.

Plastic plating production line of DC current meter is actually and supporting shunt millivolt (45mv 75mV or) voltage meter, if two block header shared shunt should be the header in parallel rather than in series.
In order to reduce the long distance signal transmission attenuation, the fault can also use two tables are arranged near the shunt way.

2.2 production examples 2

1) the failure phenomenon of chromium plating production line in accordance with a new process of production, the frequent emergence of DC voltage meter and DC current meter damage phenomenon, mainly the instrument pointer broken, instrument display failure.

2) failure cause analysis and elimination method of the first analysis of the new and old technology on equipment, especially for the requirements of the instrument. In the new process, a full load of reverse current impact is performed before each plating. And the original equipment configuration of the DC current meter and DC voltage table are single deflection, so the reverse voltage and reverse current under the impact of the meter, the meter pointer will be frequent damage. Replacement of the corresponding two-way instrument, troubleshooting.

2.3 production examples 3

1) fault phenomenon new electroplating production line three DC voltmeter voltage value is not consistent, affecting the transfer of equipment. Three voltage meter are respectively arranged in the rectifying power supply body, DC into the workshop first end position and the bath side.

2) the fault reason analysis and the elimination method to use the DC voltage meter to measure the voltage value of three place, all and the meter indication. Measurement of resistance normal bus bridge. Check the DC voltage meter connection line, in line with the requirements of the instrument specification. But three meter leads are from DC power supply, lead is too long lead to large measurement error. Three measurement points are from the nearest bus according to the specification of [1] wiring, troubleshooting.

This fault can also use bold instrument leads, without changing the voltage signal sampling point solution. At this point to the measured wire voltage loss does not exceed the allowable value is appropriate. The author thinks that the former plan is more reasonable and simple.

3 - copper busbar connection error production examples
1) the failure phenomenon of the new plastic electroplating production line running warranty period (twenty days), three DC voltage shows the value is not consistent, the impact of the final transfer of equipment. Three voltage meter are respectively arranged in the rectifying power supply body, DC into the studio head position, bath side. The value of the top two shows the same value, and the value of the voltage at the plating bath is low 2V. This issue has not occurred during the handover of equipment installation.

2) failure analysis and exclusion method, it is found that the bus the positive and the negative poles of both a big resistance, running dripping method of examination, found that bus bar on a few bolt butt joint overheating, as the location of voltage loss. Open the connection parts, fine sandpaper grinding oxide layer and coated with conductive paste, the bolt replacement for copper bolts, reconnect, troubleshooting. In circuit design should make copper busbar connection part is larger than the width, the surface of the copper matrix can also uses the tin plating layer, in order to avoid oxidation.
Check the bus hot spot drip method, is a kind of simple and power check in high current low voltage busbar