Copper bar is a kind of high current conductive product, which is suitable for high and low voltage electric appliance, switch contact, distribution equipment, busbar slot, etc. . The electrical copper bar has the advantages of low resistivity and large bending degree. Copper bars are widely used in electrical equipment, especially in complete sets of distribution equipment. Copper bars are commonly used in U, V, W phase bus bars and PE bus bars in distribution cabinets The copper bar is usually marked with the color letters or painted with the color paint, the copper bar of u phase is painted with yellow, the copper bar of V phase is painted with green, the copper bar of w phase is painted with red, and the copper bar of Pe bus bar is painted with the color of yellow and green. 

Three processes for surface treatment of copper bars are as follows: 1. Copper Strip paint; 2. Tin Plating on Copper Bar; 3. Copper row coating protective agent;

1.Copper Strip paint

(1)This craft belongs to the elimination backwardness craft, now seldom uses. 

(2) The bus bar of the three-phase electric power is painted in black, and a color mark is pasted in a conspicuous place. Phase A is yellow, phase B is Green, phase C is red, zero or neutral wires are painted in light blue, and safety grounding wires are painted alternately in yellow and green, can Not distinguish between polarity, phase sequence of white paint. 

(3)The Positive Pole of DC circuit is painted with Brown paint, the negative pole is painted with blue paint, and the ground wire is painted with light blue paint.

 (4)Check the busbar paint is uniform, whether there is a sagging phenomenon.

 (5)Busbar can be painted or painted, color should be uniform, edge should be neat, no paint leakage, paint hanging phenomenon, busbar connection shall not touch paint. 

(6) The painting boundary of each phase Busbar of the same element and the same end should be free from obvious irregularity. Kill. 

(7)The painting boundary of the bus bar is flush.

2.Tin Plating on copper bar

(1) The craft is mature. Operation Cycle Short, commonly used. 

(2)Weak point: the surface darkens over time, the human hand can not do. It's not green!

(3)Process flow

1) surface polishing and deoiling pretreatment → pure water washing → high pb sn alloy tap water washing → pure water washing → tin plating → tap water spray washing → neutralization (Na2HPO4 + Na3PO4)→ tap water spray washing → stearic acid soaking → tap water spray washing → hot pure water soaking → drying. 

2) Copper bar surface treatment process polishing: whether manual or mechanical are slow, and tired, dust is very serious, cleaning surface oxide skin, small burr. (with quartz sand, glass balls).

(4)The function and process flow of each component of plating solution

 (5)Bright sulfate tin plating bath is mainly composed of Tin(II) sulfate and sulfuric acid, the content of which varies with the additives used in the production.

1) The Tin(II) sulfate is the main salt, the content is generally controlled at 40 ~ 100g/l. However, the results of production experiments show that high concentration of Tin(II) sulfate can increase the CATHODIC current density and speed up the deposition, but it can obviously decrease the dispersion ability of the plating solution, decrease the crystal size and bright area of the coating, and even shorten the treatment cycle of the plating solution. 

2) The content of SNSO4 should be controlled at 20 ~ 60g/l. If the lower limit is taken, the excellent products can be produced by means of "compensation" by speeding up the circulation speed of bath and the moving speed of electrode (cathode or anode) , but not too low.

(6) Sulfuric acid can reduce the activity of stannous ion, prevent the hydrolysis of stannous ion, improve the conductivity of bath and the efficiency of anode current. When the sulfuric acid content is insufficient, the stannous ion is easy to oxidize to tetravalent tin. Kill. 

(7)From the point of view of kinetics, when enough H2SO4 is available, it can slow down the hydrolysis of Tin (II) and stabilize the plating solution.

(8) Additives

1) . Tin Plating Brightener is generally made up of main brightener, auxiliary brightener and carrier Brightener. 

2) . Main brightener 

3.) Acid bright tin plating brightener varieties, can be summarized into two categories: the first is mainly aromatic aldehydes, aromatic ketones, esters and unsaturated organic acids? The derivatives of?-Ene, the second kind is mainly Schiff base (the basic structural unit is-ch = N-FO-CH = ch-or-ch = ch-ch = N -) , which is formed by condensation of Acetaldehyde and o-methylpropylamine. It is an effective brightening agent for acid bright tin plating. It can be used alone or in combination with class L brightening agent . 

4) . The brightening effect of the organic brightener is mainly the adsorption on the cathode, the adsorption on the cathode is too strong or too weak to obtain the ideal bright coating Because the adsorption is too strong, the desorption potential is too negative, the hydrogen evolution is serious, easy to Form Pinhole; . Only proper adsorption can achieve good light effect . 

5) Therefore, the additives with too strong, proper and too weak adsorption should be used together to achieve the goal of moderate adsorption and wide range of adsorption potential, and the amount of each combination should be determined by experiment .

6)At present, benzalacetone, Cuminaldehyde, Benzophenone, o-fluorobenzaldehyde and so on can be used as main brighteners, among which benzalacetone is commonly used Because the main brightener can only play a role in a certain range of current density, so the use alone can not obtain an ideal coating, but if used in conjunction with the auxiliary brightener can play a synergistic effect, so that the coating crystallization refinement, bright current density region to further expand .

7) Among these additives are aliphatic aldehydes and some organic acids, such as Formaldehyde, acrylic acid, cinnamic acid, etc. . 

8) . Carrier Brightener 

9) The solubility of most organic brighteners in water is very small, so the amount of them adsorbed on the cathode is also small, so it is not suitable to add them into the plating solution alone Therefore, in order to give full play to the effect of Brightener, it is necessary to add some Surfactant, using its solubilization to increase the content of brightener in the plating solution, these Surfactant called carrier Brightener, also known as dispersant At the same time it also has wetting and refining crystallization and other functions . 

10) The first carrier brighteners were anionic Surfactant, but their adsorption on the cathode was weak Later, non-ionic Surfactant, such as Polyethylene glycol and polyoxypropylene ether, were developed, which not only have wetting and dispersing effect, but also can restrain h 2 precipitation and SN 2 + discharge to refine the grain of the coating . Among the dispersants, OP emulsifier is widely used . 

(10)Stabilizer

1) . The acidic tin plating bath with Tin(II) sulfate as the main salt will be turbid after half a month of continuous operation, and it is difficult to plating out qualified products, a stabilizer is needed. 

2.) Most of the acid tin plating stabilizers in common use are SN2 + complexing agents, such as oxalic acid, citric acid, tartaric acid, etc. . In addition, a catalyst also has the role of stabilizing plating solution, production shows that in the case of continuous production, adding this catalyst plating solution can maintain more than half a year of clear and turbidity

(11) flocculants

1)Up to now, there is not a kind of stabilizer: it can keep the bath stable and clear for a long time, so SN4 + is unavoidable. With the accumulation of SN4 + , the bath gradually becomes muddy, the sediment increases, the bright area of the plating layer becomes smaller, the uniformity becomes worse, even appears dark, and so on phenomenon, must carry on the flocculant treatment to the plating solution at this time.

 2) . Inorganic and organic flocculants are divided into two categories, inorganic flocculants have a variety of salts, active silica, organic flocculants can be divided into anion, cation, non-ion 3. The anionic flocculants are mainly epoxyamine Copolymer, Polyethylenimine, polyvinylamine derivatives, etc. . The anionic flocculants are mainly Polyacrylamide hydrolysate, Polyacrylamide, sodium sulfonate, etc. . The non-ionic flocculants are mainly Polyacrylamide, urea-formaldehyde polymer, etc. . 

3) . The combination of Polyacrylamide and inorganic flocculant is very good, and has no effect on the performance of the plating solution, but the settling speed is too slow, up to 48 hours. The effect of epoxy Amine Copolymer is good, but excessive use has some influence on the plating solution, seriously affects the brightness of the coating, but the deposition speed is very fast, generally within 2 hours can be completely precipitated (do not use excessive) .

3.Copper Bar coating protective agent

(1)ADVANTAGES: maintenance of copper row primary color, slightly lower than the cost of tin plating. Disadvantages: Long Operation Cycle.

 (2)Process flow 

(3)Polishing pretreatment → pure water washing → acid washing passivation → drying moisture → JLR-510 protective treatment → flowing water cleaning → soaking in hot water (about 100 °C, for the purpose of letting moisture volatilize or dry)→ drying → packing closure 

(4) Copper bar surface treatment process polishing: whether manual or mechanical are slow, and tired, dust is very serious, cleaning surface oxide skin, small burr. (with quartz sand, glass balls). 

(5)The main process of pickling and passivation is: PRETREATMENT (cleaning surface)→ pickling, passivation and rinsing → post treatment (product protection) . The main content of pre-treatment is to purify the surface of pickling, passivation, remove all kinds of surface grease, welding spatter, welding scar, oxide skin and so on. Pickling and passivation can be treated separately from pickling and passivation, and both pickling and passivation can be treated simultaneously. When pickling and passivation are treated separately, the whole work piece is immersed in the acid pickling passivation solution, which is suitable for small parts or pipelines and linear equipment with liquid circulation. 

(6)When the acid cleaning and passivation are combined into one treatment, the method of liquid immersion can be used (the scope of application is the same as above) , or the paste can be applied, because the paste is easy to apply, and the paste can be maintained in different positions without loss and wettability for a long time, thus, the necessary time of acid pickling and passivation is ensured. 6. Copper anti-oxidation protective agent JLR-510 copper anti-oxidation protective agent stable performance, non-toxic, tasteless, non-volatile, non-deliquescent, non-decomposition, non-sublimation do not adsorb dust and H2s, , , SO2 and other harmful gases, . Can effectively resist the humid salt spray, mold and other metal erosion, has good wettability and high corrosion resistance . Copper anti-oxidation protective agent also excellent electrical properties, it has the triple functions of dehydration, anti-tarnishing and anti-corrosion, has no corrosion to metal, and has obvious anti-corrosion protection to copper, silver and imitation gold coating, especially to prevent the surface of copper and imitation gold from tarnishing, the effect is remarkable This product can also be added with other additives, such as water-based, solvent-based sealant, gloss gold oil, rust inhibitor and other products, for copper, gold, silver, zinc, steel and other metal rust played an inestimable role. . 

(7)Plastic packagings are recommended. No metal packagings shall be used except for copper. Then the JLR-510 copper parts anti-oxidation protection liquid is used directly. . 

(8)This working fluid can be protected at room temperature and at elevated temperature, but it is recommended to be used at elevated temperature for higher efficiency and better results . However, it is advisable to choose a reasonable way of heating, if the built-in way, heating tube must be copper, or use quartz and polytetrafluoroethylene (Teflon) heating tube, if it is other metal heating tube, will change the performance of liquid medicine, not suitable.

9. Use:

1) . Chemical Polishing and cleaning after deoiling? After plating copper bright acid or other copper; rinse twice with running water and then rinse once with deionized water (this will make the solution with as few impurities as possible, thus extending the life of the solution) .

2) If it is operated at normal temperature, it must be treated in the working liquid for 5-10 minutes, in principle not less than 5 minutes, because at room temperature, the passivation film formed by the liquid in the copper layer will be about 5 minutes, if the product requires more than 8 hours of salt spray test, it is recommended to be used at elevated temperature; 

3). If it is used under the condition of heating, the temperature should be controlled between 60-70 °c, the best is about 65 °C. Under this condition, it takes only 2 minutes (the suggested treatment time is 3 minutes) to form a complete, uniform and lustrous protective film to achieve the best anti-tarnishing effect. 

4) . After being treated in the above way, wash with running water for 1 minute, shake dry to the surface of the work piece without water, take out the water at the temperature of 70-80 °C to dry or wipe the surface.

(10)Tank maintenance:

1) . The service life of the working fluid largely depends on the degree of cleaning before work. Pickling parts to be washed clean, there can be no residual acid into the passivation solution. Therefore, the passivation solution should be separated from the pickling solution to avoid the entry of CR (VI) and CR (III) ions, and the residual solution should be avoided before the complex product enters the anti-tarnish tank.

 2) . Equipment Selection: The selection of equipment is the key, generally plastic containers, heating pipes must be copper, or choose external heating method (can be provided by my company with related design and temperature control devices) . 

3) . Don't let any other metal parts into the solution. 

4) . When the Ph of the solution exceeds 6-7 ± 3, the solution should be discarded. If the time required for anti-tarnishing is not high, it can be used as the standard. In general, the solution has good passivation under the condition of Ph 2-9. If the quality requirement is high, the Ph can be controlled within the range of 5-7 and 4-8.

 5) . In addition, the anti-discoloration tank before the please tank need to check its PH value with a Ph test paper, if found out that water from neutral, it is recommended to replace immediately please water, otherwise the anti-discoloration agent will be affected. Waste Water Treatment: The waste liquid of this product can be directly discharged.

(11)Performance test data of Copper Protection passivation solution: Processing Conditions: Copper Protection Solution Against Oxidation, temperature 65-70 °C, time 2 minutes. CONTRAST CONDITIONS: traditional chromic acid treatment. 

Source: Electrical Information