DO’S and DON’TS for CED line

DON’TS

1)      Never enter CED tunnel while rectifier  is ON

2)      Do not add paint / additives directly to bath paint. It must be added through dosing pump with delivery at pump suction.

3)      Do not use any contaminated bucket for paint dosing. A separate bucket (100 liters) to be arranged separately for CED dosing.

4)      Do not dip any wooden / mild steel stirrer either in bath or supply paint. Use either plastic or SS stirrer.

5)      Do not run production with anolyte circulation OFF.

6)      Do not turn off UF feed pump without proper flushing of UF modules

7)      Do not keep the UF modules on paint without circulation for more than 15 min (or KOCH recommended time)

8)      Do not run turbid UF through pump mechanical seals.

9)      Do not run production with CED tank exit spray OFF.

10)  Do not load components with rust.

11)  Do not load components with heavy oil without proper wiping.

12)  Do not allow any foaming in CED tank.

13)  Do not add pigment paste without stirring the paint in barrel. Homogenize paint in barrel. Take out required quantity in bucket. Add some water to dilute it before dosing. Do not add water in supply barrel. It will result into hard settling of paint.

14)  Do not add solvent additive / pH stabilizer immediately after paste or emulsion through dosing line without flushing with DM.

15)  Do not start the production till DM4 and DM3 stages in PTC are fully operational.

16)   Do not allow bath temperature to exceed 35 deg.C as it may create harm to UF modules.

17)  Do not run production if bath temperature is less than 25 deg,C

18)   Do not run the production if oven temperature is not achieved as per set  point  as under cure gives poor film properties.

19)  Do not allow fallen parts to remain in rinses for long time.

  Do’s

1)      Test all required parameters of CED bath and rinses every day before start of production

2)      Preferably complete entire addition well before start of production

3)      CED sample to be taken from sampling point. Rinses sample to be taken from top of the tank if sampling is point not provided.

4)      In case of addition sequence, add emulsion  followed by paste. It is good practice to flush pump with DM water after addition of individual components Flush pump thoroughly after addition is complete. (i.e Dose DM water through dosing line).

Benefits of Powder Coatings

• Tough, durable, lasting coating for metals. Excellent hardness and abrasion / impact resistance gives improved product performance over most liquid coatings.
• Wide range of colors.
• Environmentally friendly outsourcing option to avoid permitting for solvent-based paints.
• Less process variation results in consistent color and appearance of the product.
• High film builds and excellent edge coverage gives better resistance to corrosion with proper pretreatment.
• Coatings can be easily formulated for specific applications such as prolonged exposure to sunlight, the ability to survive in highly corrosive environments, flexibility to allow forming after coating, or high durability and resistance to chipping.

Typical Powder Coatings Available 

Epoxy – Excellent corrosion resistance, toughness, adhesion and hardness. Poor weatherability. Can be formulated to be FDA compliant for food contact applications. Decorative or functional coatings available.

Epoxy/Polyester Hybrid – Less susceptible to yellowing when cured. Exhibits similar properties to standard epoxy coatings. Poor weatherability makes this unsuitable for outdoor use.

Polyester/Urethane – Smooth, thin film with excellent mar and chip resistance and good weatherability. These coatings are generally resistant to diluted acids, hydrocarbons and grease and oil.

Polyester/TGIC – Excellent weatherability with excellent mar, chip and corrosion resistance. Excellent edge coverage.

“EnC”s Capabilities

• Two automated powder coating lines
• Decorative and functional coatings
• High temperature coatings
• Manual and automatic coating systems
• Long or short runs in any color
• Coatings available in standard or metallic, high gloss to low gloss, smooth, textured or wrinkled
• 7-stage phosphate in-line immersion pretreatment system with laser scale removal capabilities
• Part sizes up to 5 feet long.

Web Hosting India

stage 2. loading for auto line process

Stage 3. degreasing  chemical -non-caustic alkaline cleaner compound chemical . Operating temperature of 20ºC t0 30º C.suitable for mild steel brass aluminum,copper &  steel also.  its  applies cleaner  to remove light surface oxides as well as any remaining lubricants.

stage 4. Running water rinsing Ambient operating temperature. This stage removes soils loosened by cleaner as well as removing cleaner residue

stage 5. De ionized Rinse Conditioner -DI Rinse Conditioner  Ambient operating temperature. This stage prepares the cast/metal surface to accept the Hazard free non phosphate coating,

stage 6. User friendly,environment friendly ,Hazard free non phosphate coating- For multi metal system based , Chromium 3 generation Produces uniform, compact nano size base coating for excellent corrosion resistance and adhesion protective coating free of phosphates, nitrates, zinc, nickel, manganese and VOC with RoHS(EU Directive 2002/95/EC) & WEEE (EU Directive 2002/96/EC) & ELV compliance . Continuous chemical movements & spray for 02 solubility in chemical available here. 

Stage 7. Ultraviolet water treated De ionized Rinse .Ambient operating temperature. This stage removes the salts and stops coating reaction .It lowers the surface conductivity of the part to prepare it for e-coating

stage 8. ELECTROCOAT BATH- temp. 18 witH 2% UP/DOWN-applying coating in bath.The electrocoat bath and ancillary equipment zone is where the coating is applied and the process control equipment operates. The electrocoat bath consists of 80-90% deionized water and 10-20% paint solids. The deionized water acts as the carrier for the paint solids which are under constant agitation. The solids consist of resin and pigment. Resin is the backbone of the final paint film and provides corrosion protection, durability and toughness. Pigments are used to provide color and gloss.

In cathodic electrocoating, the product is given a negative charge, attracting the positively charged paint particles. The negative electrical charge of the metal part attracts positively charged paint particles. Reversing the polarities used in the anodic process greatly reduces the amount of iron entering the cured paint film and enhances the properties of cathodic products. Cathodic coatings are high-performance coatings with excellent corrosion resistance and can be formulated for exterior durability.

stage 9.PERMEATE RINSE 1st-DI  Water. Ambient operating temperature. This stage removes excess e-coat from the parts. It counter flows paint solids back to the e-coat tank to enable a high efficient operation

stage 10.PERMEATE RINSE 2nd-DI  Water. Ambient operating temperature. This stage again removes excess e-coat from the parts. It counter flows paint solids back to the e-coat tank to enable a high efficient operation.

stage 11. PERMEATE RINSE 3rd-DI  Water. Ambient operating temperature. This stage removes excess e-coat from the parts. It counter flows paint solids back to the e-coat tank to enable a high efficient operation

stage 12.PERMEATE RINSE 4th-DI  Water with permeate comes from ultrafilter. Ambient operating temperature. This stage removes excess e-coat from the parts. It counter flows paint solids back to the e-coat tank to enable a high efficient operation .

everal analytical tests should be performed daily to enhance the performance and stability of your electrocoat paint bath. These tests include percent solids, pigment to binder ratio, pH, and conductivity. Additional tests may be necessary as well, such as acid/base titrations and solvent analyses, depending on the type of electrocoat product you use. Your paint supplier should assign specification ranges for each test, and every effort should be taken to operate the paint tank within these specifications. Maintaining your electrocoat bath within the recommended ranges will enable you to obtain the best possible performance on line.

Many factors can be impacted by operating your tank in specification, including appearance, hiding, gloss, color control, film coalescence, bath solubility, cure response, filter media and ultrafilter performance, part rinsing, throwing power, and, most importantly, cost! It is important when testing your paint bath that proper instrumentation and test methods be used to ensure accurate results. An electrocoat tank that is properly maintained will experience minimal downtime and re-working of parts, as well as avoid potentially expensive activities associated with problem solving and corrective action.

Laboratory Equipment and Instrumentation
A number of instruments are used to perform the tests that are necessary to control your electrocoat paint bath. The following table lists the basic equipment needed. Detailed descriptions of the laboratory equipment can be found in the individual test methods at the end.

It is important to note that all laboratory instruments should be properly maintained and kept in good working order. Routine calibrations and periodic maintenance need to take place to ensure that accurate data can be generated.

Instrument Calibration and Verification/ISO Considerations
Analytical laboratories are easy targets for ISO and QS inspectors, who closely scrutinize data generation and instrument calibration under elements 4.9 Process Control, 4.11 Inspection, Measuring, and Test Equipment, and 4.18 Training. You must be able to prove to an auditor that your laboratory instruments are working properly, and that the personnel involved with conducting the tests are trained to perform them correctly. Therefore, it is important to initiate and execute a workable control plan at your facility. This document tells the auditor what facets of your operation you plan to control to assure quality. Your control plan is also the document that the auditor will reference when conducting an audit. A simple guideline to survive an ISO or QS audit of your analytical laboratory is to “say what you do, and do what you say.”

Some laboratory instruments require more frequent calibration and/or verification than others do. The following table provides a general guideline to ensure that your equipment is operating properly.

Any activity associated with instrument calibration or verification should be recorded on detailed log sheets. Be certain your operators are properly trained and competent to perform these functions. Use certified buffer solutions and calibration standards for your pH and conductivity meters and make sure to dispose of these materials when the shelf life expires. Use NIST traceable weights when calibrating your balance and certified temperature probes to verify your solids oven and muffle furnace. If one of your laboratory instruments is not working properly or cannot be calibrated, place an “out-of-service” tag on it until it the instrument is repaired and can be brought back into compliance. Signing and dating any lab record proves that the activity occurred, so this aspect is critical.

Use unique identification labels for any samples being tested in the laboratory. The ID of the sample should match the ID indicated on the daily log-sheet that is used to record test data. Keep your test methods on-hand so you can show an auditor that everyone involved with testing samples follows the same methods to generate data.

Above all, whether calibrating your instruments or recording test data, do not attempt to “fudge” numbers. ISO auditors are like bloodhounds, and once they get on the trail of a questionable record they will trace it to its source in an attempt to discover if the paper trail is complete. You can risk losing your ISO or QS status if an auditor discovers falsified records during an audit.

Operator Training and Test Methods
How do you know your operators in the laboratory are performing the tests properly? The best way to achieve this is to create and use Standard Operating Practices (SOP’s) that reference accepted test methods prescribed by the American Society for Testing and Materials (ASTM International). If everyone conducting tests at your facility uses the same test methods, the chances of duplicating results between operators and controlling your paint tank properly are greatly increased. Operators should be trained using your laboratory ’s SOP ’s to guide them through each test procedure. Training checklists can be created for anyone conducting tests in the lab, and laboratory operators should demonstrate competence in each test to be considered fully trained.

The test methods we follow in our laboratory can be found at the end of this report. All of these tests should be performed at least once per day, or preferably once per shift to maintain the best possible control over your electrocoat paint bath. Samples should be run in duplicate to ensure the results are accurate before making any adjustments to the paint tank. Properly trained operators using approved test methods are essential to a successful electrocoat finishing operation.

Interpretation of Results/Paint Bath Adjustments
How do you interpret and respond to the data you have generated? It is important to know what makes your paint bath “tick” to properly interpret the data. There are three primary components of your electrocoat paint bath: pigment, resin, and solvent. The solvents found in electrocoat are deionized water and significantly smaller quantities of organic co-solvents, which are typically glycol ethers. There are numerous relationships that occur between the various paint components, and the analytical tests you perform can provide valuable insight into these relationships. The results you generate are used to make adjustments to your paint bath, so accuracy and precision are critical to ensure proper paint bath adjustments will take place.

Solids
The solids portion of your electrocoat paint bath is comprised of the pigment and resin components, therefore: %Solids = %Pigment + %Resin. Electrocoat paint is generally low in solids at 10–20% by weight. The remainder is primarily water, hence the viscosity of an electrocoat paint bath is “water-thin” and the solids have a tendency to settle. The paint tank needs to be constantly agitated to keep the solids particles in suspension. The same principle holds true for the sample being tested for solids. It needs to be representative of the electrocoat bath and should be well agitated before testing. If settled material remains in the bottom of the sample container, the solids result will be erroneous. In general, pigment solids tend to settle more readily than resin solids.

Bath solids play a major role in the overall health of your electrocoat system. Baths running in spec for solids have better inherent stability than baths whose solids are low. Low-solids paint baths tend to be less robust and are more prone to problems associated with contamination, as contaminants tend to have an amplified effect on a low-solids bath. Additionally, low solids tanks are more likely to experience difficulty building film and film appearance may be poor. A common cure for many electrocoat paint problems is to add fresh feed, since higher solids impart more robustness to the system and tend to dilute contaminants.

If your solids result is low, add the appropriate amount of fresh resin and paste components (i.e. feed) to bring the value into specification. If the solids result is high, coating parts will effectively lower the solids. If your bath solids are significantly high, it may be necessary to transfer a portion of the electrocoat bath into a storage tank and add deionized water to the tank to lower the solids. This type of action is rarely necessary though, and should only be performed as a “last resort.”

Pigment to Binder Ratio (P/B)
The P/B result is used to determine how much pigment is in your electrocoat paint bath. The percentage of pigment present is usually shown in relationship to the amount of resin or binder, therefore: %Pigment to Binder Ratio = %Pigment ÷ %Binder.

The higher the pigment to binder ratio, the more pigmentation is in the system; the lower the pigment to binder ratio, the less pigmentation is in the system. Some of the factors impacted by the amount of pigment present in the paint bath include hiding, gloss, color control, and cure.

Dark colors generally need less pigmentation to achieve hiding than lighter colors, so the tendency for pigments to settle out of the paint bath is somewhat diminished. As in solids testing, the sample needs to be well agitated before conducting the test.

Typical P/B ratios for black electrocoat paints range from 0.05 to 0.20; typical P/B ratios for white and light gray electrocoat paints range from 0.35 to 0.55.

The P/B test method involves the use of a muffle furnace, which incinerates all organic components of the paint. Paints with high concentrations of organic pigments, such as carbon-based blacks and reds, require the use of a correction factor, which inherently reduces the accuracy of the test. It may be necessary to use an alternate test method for these types of paints. The muffle furnace method works well for paints that contain mostly inorganic pigments, such as whites and grays.

If your P/B result is low, add the appropriate amount of pigment paste to bring the value into spec. If your P/B result is high, add resin. Note that paste and resin additions associated with P/B adjustments will also cause an increase in overall solids, but this increase tends to be relatively small unless copious amounts are added.

It should be mentioned that P/B testing is not necessary for one-component electrocoat products, since the pigment levels are controlled as part of the manufacturing process. Hence, one-component technology is advantageous from a cost standpoint given that the daily P/B test can be eliminated, and a muffle furnace is not needed in the analytical laboratory.

pH
In electrocoat, pH is an indication of overall bath solubility. For cationic electrocoat, pH is acidic (<7.0); for anionic electrocoat, pH is basic (>7.0). Note that the pH result is on a logarithmic scale, so what may appear to be a small change in pH actually represents a large change in the overall chemistry of the paint bath. The following table represents pH results obtained from a cationic epoxy electrocoat paint bath:

The out-of-spec low result obtained from Sample 1 indicates that excess acid is present in the paint tank. Since cationic electrocoat paints are solubilized by acidic species, excess acid can lead to aggressive post rinses and the occurrence of film re-dissolution; i.e. the deposited paint film can be dissolved back into the paint bath. If your film builds are low under normal coating conditions, check the bath pH; it may be detrimentally low (or high, for anionic electrocoat).

Conversely, the out-of-spec high result obtained from Sample 2 indicates that insufficient acid is present in the paint system. This can cause the electrocoat bath to “kick-out,” which is manifested as settled material on horizontal surfaces of parts and/or abnormal bag filter and ultrafilter fouling.

In cationic electrocoat systems, high pH can be adjusted down by adding appropriate acids into the paint bath. Low pH can be adjusted up by regulating the conductivity set point on the anolyte system. Basic materials should never be added to a cationic electrocoat bath, as they are incompatible and will cause the bath to kick-out immediately. Acidic species are imparted into cationic paint baths as part of the coating process, and the anolyte system is used to remove acidic materials from the paint. Adjusting the anolyte conductivity set point to a low value will remove more acid from the paint bath (so the pH of the bath will go up); a high anolyte conductivity set point will remove less acid from the paint bath (so the pH of the bath will go down). Ideally, the conductivity set point of the anolyte is adjusted to maintain a relatively constant bath pH within the specification range.

For anionic (basic) electrocoat systems, high pH can be adjusted by directing permeate into the waste stream, since the basic materials used to solubilize the paint system are water miscible and can be removed through ultrafiltration. Care must be taken not to over-purge the paint bath though, as this can actually lead to even higher pH through the removal of excess acidic species.

If the pH is low, add amine until the pH is in spec. Acidic materials should never be added to an anionic electrocoat bath, as they are incompatible and will cause the bath to kick-out.

Conductivity
In electrocoat, DC electricity is used to drive the paint to the part, so the paint bath must be capable of conducting electricity. The conductivity result is used to determine how conductive your electrocoat paint bath is. The process of deionizing water implies that any ionic components present in the water will be removed; therefore the conductivity of deionized water should be relatively low. For electrocoating purposes, the conductivity of deionized water should be less than 10 µmhos/cm.

The fact that your paint bath is conductive indicates that one of the primary ingredients in the paint is also conductive. Since we use deionized water for electrocoat, this rules out conductivity of water as the source. In fact, the resin portion of the paint imparts the majority of the conductivity to the paint system. As such, increases in bath solids through resin additions will lead to an increase in overall bath conductivity. Now that we have established a relationship between bath solids and conductivity, let’s discuss how to interpret conductivity data. Consider the following example:

In this case, the conductivity of the sample in question is high out-of-spec, while the solids are in spec. Assuming the test method used to generate the data is correct, the high conductivity of this sample is an indication that ionic species have contaminated the bath. The paint bath responds by showing an increase in overall conductivity and can also respond by coating parts with inferior film appearance (typically “patchy roughness”) and substandard properties. Several sources of ionic contamination are common, but the most typical is highly conductive pretreatment chemicals being carried into the electrocoat bath by way of the part being coated. Another frequent source is poor quality water. Unless corrective action is taken, serious implications can result and costs will be incurred.

One important point to note is that the temperature of the sample is critical when measuring conductivity. Sample temperature and the corresponding conductivity result move together on a nearly linear scale, so the lower the sample temperature, the lower the conductivity result; the higher the sample temperature, the higher the conductivity result. Our conductivity test method describes a procedure in which 25C (77F) is the proper sample temperature to use.

If the conductivity result is high, direct the permeate flow into your waste stream. This will remove water and any components that are soluble in water, including ionic materials, certain co-solvents, and various acidic and basic species. For some paints, solvent and meq acid and base levels should be tested after purging the electrocoat bath, as they may need to be replenished. If the conductivity result is low (which can occur if your paint bath is over-purged), add resin until the conductivity result is in spec.

Note that resin additions will also affect bath solids and P/B ratio, so these parameters may need to be adjusted as well.

Record Keeping/Database Operations
Data generated from each test should be stored in some fashion. Daily log sheets or laboratory worksheets are useful to record information about the sample, and copies can be kept near the coating station for quick reference. A variety of computer applications may also be used to store and manipulate analytical data. The following graph depicts pH results over a three-month period.

Figure 1. Example of a pH Graph
Graphical interpretations of data can be useful tools in detecting trends. The graph shows periods where bath pH increased and decreased over time. The assumption can be made that these trends prompted action from the operator to avoid a potentially detrimental and costly situation.

Addressing Discrepancies Between Labs
Identical samples tested in different laboratories by different operators rarely generate identical data. Knowing that there is variation inherent to any test performed tells us we should not be surprised if questionable results are obtained in one lab and not in another. Following the same test methods and using laboratory instruments that are properly calibrated can minimize test variation and experimental error. It is important to know that your equipment is functioning correctly. In addition, running tests with multiple samples in duplicate or triplicate increases the statistical accuracy and precision of the data generated.

Proper maintenance of your electrocoat paint bath through analytical testing is critical to managing a cost-effective coatings system. Trained operators using approved test methods will enable appropriate adjustments to be made to your paint bath to keep things running smoothly with minimal downtime and re-working of parts. Performing the following tests on a daily basis and adjusting your electrocoat bath accordingly will enable you to realize significant cost savings at your facility.

Test Methods

Percent Solids Determination

Scope
This method describes the procedure for determining solids content of electrocoat paint baths using a forced-air convection oven.

Safety

• This test procedure may involve hazardous materials, operations, and equipment. This procedure does not purport to address all of the safety concerns associated with its use. It is the responsibility of the users of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
• Safety goggles and solvent resistant gloves should be worn when working with wet samples.
• Heat resistant gloves should be worn when removing samples from oven.
• Personnel using this method should be familiar with the safety and handling precautions of the test materials and apparatus used.

Equipment

• Safety Glasses
• Heat Resistant Gloves
• Forced Air Convection Oven capable of maintaining constant temperature of 110C (230F), accurate to + 2C
• Disposable Aluminum Weighing Dishes (18 x 57mm, with handle)
• Disposable Transfer Pipettes
• Balance, accurate to 0.001g

Procedure
1.Place the aluminum dishes in an oven for 30 minutes at 110C (pre-bake).
2.Store conditioned dishes in a desiccator until needed.
3.Test two samples.
4.Number an aluminum-weighing dish for each sample.
5.Record the weight of the empty dish (B).
6.Add 4.0 grams of well-mixed sample to the dish and record the weight (A).
7.Place the sample dish on a panel in the oven for one hour at 110C (230F); the sample must lay flat to insure uniform evaporation; the oven must already be preheated to 110C (230F).
8.Remove the sample dish from the oven; place immediately in desiccator; allow to cool; record the weight (D).

Notes
Avoid touching dishes with your bare hands. Use tongs or pliers to move dishes when weighing. Oil present on your hands could affect results. If un-evaporated liquid is still present in dishes after one hour, verify oven temperature and repeat the test.

Calculation
D =Weight of Solids and Dish B =Weight of Empty Dish A =Weight of Sample and Dish

Pigment/Binder Ratio Determination (P/B)

Scope
This method covers the procedure for determining the pigment-to-binder ratio of electrocoat paint baths.

Safety

• This test procedure may involve hazardous materials, operations, and equipment. This procedure does not purport to address all of the safety concerns associated with its use. It is the responsibility of the users of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
• Safety goggles and solvent resistant gloves should be worn when working with wet samples.
• Heat resistant gloves should be worn when removing samples from oven.
• Personnel using this method should be familiar with the safety and handling precautions of the test materials and apparatus used.

Equipment

• Safety Glasses
• Heat Resistant Gloves
• Forced-Air Convection Oven capable of maintaining constant temperature of 110C (230F), accurate to + 2C
• Disposable Aluminum Weighing Dishes (18 x 57mm, with handle)
• Disposable Transfer Pipettes
• Balance, accurate to 0.001g
• Muffle Furnace capable of maintaining constant temperature of 500C (932F), accurate to + 4C

Procedure
1.Place the aluminum dishes in an oven for 30 minutes at 110C (pre-bake).
2.Store conditioned dishes in a desiccator until needed.
3.Test two samples.
4.Number two aluminum weighing dishes for each sample.
5.Stack the dishes on top of each other and record the weight of both dishes (B).
6.Add 4.0 grams of well-mixed bath sample to only the top dish and record the total weight (A).
7.Place empty dish beside sample dish on a panel in the oven for one hour at 110C (230F); the sample must lay flat to insure uniform evaporation. Note: The oven should already be preheated to 110C.
8.Remove from oven; lace empty dish securely on top of paint sample dish. Fold over tabs on side of dishes to help secure dishes together; place immediately in desiccator; allow to cool; record the weight (D).
9.Place in muffle furnace and bake for 90 minutes at 500C. Note: The muffle furnace should initially be at ambient temperature. The 90-minute bake begins when the muffle furnace reaches 500C.
10.Remove from furnace; allow dishes to cool; record the total weight (H). Note: The solids and pigment/binder tests can be combined with the % solids calculated between Steps #5 and #8.

Calculation
H =Weight of Ash and Dish
B =Weight of Empty Dish
A =Weight of Sample and Dish
% Pigment = %Ash x Correction Factor*
N = %Pigment
G = %Solids

*The Correction Factor corrects for the amount of organic pigment present in the formulation, which is removed during ashing. Your coatings supplier should provide a Correction Factor, if applicable. The Correction Factor is primarily used for black or bright red coatings. Most other colors will have a correction factor of 1.0.

pH Determination

Scope
This method describes the procedure for determining pH of electrocoat paint baths.

Safety
This test procedure may involve hazardous materials, operations, and equipment. This procedure does not purport to address all of the safety concerns associated with its use. It is the responsibility of the users of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Safety goggles and rubber gloves should be used. Personnel using this method should be familiar with the safety and handling precautions of the test materials and apparatus used.

Equipment

• pH Meter With Electrode(s)
• 250 ml Beaker

Reagents: Anionic Electrocoat

• Certified Buffer Solution, pH 7.0
• Certified Buffer Solution, pH 8.0
• Certified Buffer Solution, pH 10.0

Reagents: Cationic Electrocoat

• Certified Buffer Solution, pH 4.0
• Certified Buffer Solution, pH 6.0
• Certified Buffer Solution, pH 7.0

Note
Never pour reagents back into original container; dispose of after each use or maintain separate containers and change weekly. Observe expiration dates on buffer containers.

Procedure
Follow the manufacturer ’s instructions for operating the pH meter.

Notes
It is recommended that the slope of efficiency range on the pH meter to be within the range established by the manufacturer. A tight slope of efficiency setting generates more accurate results than a wide slope of efficiency.

It is recommended to run all pH readings with samples and buffers at 77F (25C).

1.For Anionic Electrocoat, standardize the instrument with the pH 7.0 and pH 10.0 buffer solutions. Verify calibration with pH 8.0 buffer.

1a.For Cationic Electrocoat, standardize the instrument with the pH 4.0 and pH 7.0 buffer solutions. Verify calibration with pH 6.0 buffer.

2.Rinse the electrodes with distilled or deionized water and blot dry with absorbent tissue (Kimwipe/paper towel).

3.Immerse the electrodes into the beaker containing the paint sample and read the pH on the meter scale. No calculation is necessary.

4.Rinse the electrodes thoroughly with deionized water first to remove the majority of the paint. Use acetone only if necessary after a thorough water rinse to remove any remaining paint on the electrodes.

Notes: For Anionic Electrocoat, the electrodes should be placed in pH 7.0 buffer solution when not in use. For Cationic Electrocoat, the electrodes should be placed in pH 4.0 buffer solution when not in use.

Conductivity Determination

Scope
This method describes the procedure for determining the conductivity of electrocoat paint baths and DI water.

Safety

• This test procedure may involve hazardous materials, operations, and equipment. This procedure does not purport to address all of the safety concerns associated with its use. It is the responsibility of the users of this procedure to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
• Safety goggles and solvent resistant gloves should be worn when working with wet samples.
• Personnel using this method should be familiar with the safety and handling precautions of the test materials and apparatus used.

Equipment

• Conductivity Meter capable of automatically setting K factor
• Conductivity Cell With a Cell Constant of 1.0
• Thermometer, handheld digital

Reagents

• Potassium Chloride Calibration Solution (1,000 µmhos/cm traceable conductivity calibration standard) Note: Never pour used KCl solution back into original container. Dispose of after each use; observe expiration date on bottle.

Calibration Procedure
Before determining the specific conductivity of the electrocoat bath, the conductivity meter must be calibrated by using a 1,000-µmhos/cm conductivity traceable calibration standard KCI solution.

1.Be sure cell is clean by rinsing with deionized water.

2.Pour precisely 25 ml of potassium chloride calibration solution (1,000 µmhos/cm) into a beaker and adjust temperature to 77F (25C).

3.Pour calibration solution into cell.

Note: The most important part of the conductivity test is assuring 77F (25C) temperature of all measured samples. A 5F difference in temperature can change the conductivity reading by 100 µmhos/cm or more. Conductivity can also vary if less than 25 ml of standard volume is used.

4.Adjust the conductivity reading on the meter per the manufacturer ’s instructions to 1,000 µmhos/cm.

Sample Procedure
1.Be sure cell is clean by rinsing with deionized water.

2.Pour precisely 25 ml of paint bath into a beaker and adjust temperature to 77F (25C).
Note: Using the correct temperature is critical to obtain accurate results, as is having the proper volume of paint bath (25 ml). If less than 25 ml of standard volume is used, conductivity can vary.

3.Pour sample into conductivity cell.

4.Read conductivity measurement on the meter. No calculation is necessary.

5.Rinse cell thoroughly with deionized water and let clean deionized water sit in cell at all times when not in use.

Surface Preparation

a.Cleanliness of part to be painted

in pretreatment  we use Dip pretreatment system for cleanness

Soil Characterization Chart

What is a clean surface?

There are many degrees of cleanliness that can be achieved on a substrate surface and just as many ways of checking the surface for cleanliness.  The following is a list of these conditions of cleanliness and checking methods.

Clean surface – one which is free of oil and other unwanted contaminants.  The degree of cleanliness required is dependent on the operation, or process, which the part of product must pass   to.  Obviously manufacturers utilizing the cell cleaning concept or work station cleaning, are typically cleaning between process steps.  Situations like these usually do not require the degree of cleanliness needed for final pre-paint preparation.

Water break-free surface – this condition tells you that you have removed all organic soils.  The parts exiting the last pre-treatment or rinse stage prior to drying will show a uniform sheeting of the rinse water indicating an organically clean surface.  The water break-free surface has been the long-standing rest for cleanliness.  The key to this test is using fresh uncontaminated rinse water.  Detergent additives or rinse aids, used in a final rinse may hide poor cleaning.  Additionally, contaminated rinses, due to poor overflow, may also mask poor cleaning due to the surfactants’ wetting ability.

White towel test – wiping a white towel across clean and dry surfaces will indicate the effectiveness of inorganic soil removal.  Check flat surfaces and those areas most likely not to receive direct spray impingement.

A part cleanness of the part is depend on the  quality of the rinse water used.  The purpose of effective rinsing may be one or all of the following :

• Flush remaining wetted soils from the substrate.
• Neutralize, or dilute, remaining alkalinity after cleaner stages
• Maintain a wet substrate between stages
• Flush non-adherent phosphate, or conversion coating from substrate
• Cleanse excess water hardness, and salts, prior to dry-off.

Proper and adequate rinsing is critically important in pretreatment for paint/powder, when an accelerated corrosion specification is required.  The key considerations and factors which affect sound rinsing are:

• Quality of the original water
• Volume of the water supply tank in the pretreatment system
• Method of application
• Quantity of water coming into contact with the part surface 

For best excellent corrosion resistance and adhesion we used new economical user friendly, environment friendly pre treatment system for multi metal system based on new technology.

Eco friendly, Low energy, Bio-degradable, User friendly Anodic protection based Phosphating system.

We Can be used for EG, CRS,HDG and Aluminum, thereby eliminating separate lines for different metals

• Creates a visible layer for easier identification
• Produces uniform, compact nano size coating
• Simple process reducing the need for extended laboratory analysis
• Hazard free non phosphate coating, effluent treatment is simplified and less need
• Technology is based on patented Chromium 3 technology, effluent treatment need minimized
• No flash rusting after long line stoppage, reducing need for rework
• Does not contain Hydroxyl Amines or sulphates, effluent treatment is simplified
• No demand for COD and BOD, reduction in operating cost
• A simple single component system , therefore easy to handle and user friendly
• Works a low temperature of 25-35C, therefore saving of energy
• Meets the current legislation and regulations, such as RohS, WEEE, ELV
• Minimal generation of sludge( approx 1/10^th of standard zinc phosphate) less load on disposal
• Suitable for powder coating and liquid painting lines & also E-coating

In addition to this we have another sister organisation engaged in the field of  Water/Waste Water and Air pollution Control equipments.Our this company is 25 years old organisation and having its vast platform of reputed and satisfied coustomers.

Types of Powder Coatings
Powder is available in a wide variety of formulations, textures, gloss levels, and colors. Common formulations applied at c&E include; epoxy, hybrid, polyester, and silicones. Depending on the performance criteria of your specific parts, C&E can help you pick the proper formulation for your application.

Powder coating is an extremely attractive, durable, scratch resistant, chemical resistant, and UV resistant coating. Depending on the specific formulation applied, each of these properties will vary. In general, epoxies exhibit good mechanical properties but fare poorly in direct sun light. Urethanes and polyesters exhibit excellent weather ability. Silicones exhibit excellent resistance to heat.
Benefits of Powder Coating
• Environmentally-friendly: Unlike most liquid coatings, there are no solvents to evaporate in the powder coating process. We do not emit any VOCs into the air, thus minimizing the impact on the environment. Also, no paint sludge has to be disposed of because powder can be reclaimed and recycled.
• Thorough Treament: Powder coating provides superior edge coverage. Since powder coated parts have virtually no drips, runs, or sags, the reject rate is very low. In addition, part to part color consistency is held to a tolerance which is not visible to the naked eye.
• Quick Process: Parts are cured within minutes of exiting the oven.

The Powder Coating Process
The process starts at SPCI by hanging your part on an overhead conveyor. SPCI stocks a large variety of hanging fixtures in order to maximize the line density. First, the part is washed with an alkaline solution, rinsed, pretreated with iron or zinc phosphate, and rinsed again. A chrome free conversion coating for architectural aluminum can be applied if needed.

Once the part has been pretreated it is dried in a dry off oven. The next step is the electrostatic application of the powder to the part. The powder is charged by an electrode at the tip of the application gun. The powder particles pass by the electrode and picks up a negative charge. Since the parts are grounded to the conveyor, there is an electrostatic attraction of the powder particle to the part much like a magnet is attracted to a piece of steel.
The parts now enter the curing oven where the powder melts, cross links, and bonds to the surface of the part. Once the parts exit the oven and cool, they are inspected, packaged, and ready for use.

Free India Classifieds

Electrocoating, otherwise known as “E-Coat,” is a method of painting which uses electrical current to deposit the paint. The process works on the principal of “Opposites Attract” – materials with opposite electrical charges attract each other. In this system, electrodes in the coating tank create positively charged paint particles which are attracted to the negatively charged part. The paint particles are drawn to the metal part and paint is deposited on the part, forming an even, continuous film over every surface, in every crevice and corner, until the coating reaches the desired thickness. At that thickness, the film insulates the part, so attraction stops and electrocoating is complete.
C&E utilizes cathodic electrocoating, available in medium gloss black epoxy. In future we have also planned for acrylic black for more then 95% gloss & others colors lick white

Types of materials that can be Electrocoated.
Cold Rolled/Hot Rolled Steel, Galvanized Steel, Iron Castings, ZincCastings, Copper/Brass, Conductive Composites, Aluminum Extrusions and Castings, Rare Earth Magnets (NdFeB), NiZn Plated Steel, Stainless Steel, Chrome Plate.

Benefits of Electrocoating
• Environmentally friendly: Unlike most liquid coatings, there are no solvents to evaporate in the E-coat process. E-coat emits virtually no VOCs into the air, thus minimizing the impact on the environment. Also, any excess e-coat deposited or carried by the part is rinsed, reclaimed, and recycled to the electrocoat tank.
• Outstanding Performance: Electrocoating provides an extremely chemical and corrosion resistant finish. Depending on the application, it can be used as a single coat application or a base coat. Electrocoating also provides an exellent base for a variety of top coats. This “dual application advantage” creates a more decorative and durable finish.
• Adaptable for the most complex products: Electrocoating readily conforms to multifaceted configurations and yet maintains engineered tolerances on parts ensuring intended operating functions. Some examples include: internal surfaces, deep recesses, weldments, fasters, small parts, and large parts, all of which receive uniform coating (no sags or runs).
The Electrocoat process can be divided into four distinct zones:
The pretreatment zone cleans and zinc phosphates the metal to prepare the surface for electrocoating. Cleaning and zinc phosphating are essential to achieving the performance requirements desired by today’s end user of the product.

The Electrocoat bath is where the coating is applied. The electrocoat bath consists of 80-90% deionized water and 10-20% paint solids.The deionized water acts as the carrier for the paint solids which are under constant agitation. The solids consist of resin and pigment. Resin is the backbone of the final paint film and provides corrosion protection, durability, and toughness. Pigments are used to provide color and gloss.

The post rinses provide both quality and conservation. During the electrocoat process, paint is applied to a part at a certain film thickness, regulated by the amount of voltage applied. Once the coating reaches the desired film thickness, the part insulates and the coating process slows down. As the part exits the bath, paint solids cling to the surface and have to be rinsed off to maintain efficiency and aesthetics. The excess paint solids are called “drag out” or “cream coat.” These excess paint solids are returned to the tank to create a coating application efficiency above 95%.
The bake oven receives the parts after they exit the post rinses. The bake oven cross links and cures the paint film to assure maximum performance properties. Our typical bake cycles is 50 minutes at 200 degrees.