PRETREATMENT INFORMATION & TROUBLESHOOTING
Contents
1. the phosphate coating leaving it exposed and susceptible to flash rusting This flash rust affects paint adhesion durability and naturally speeds up corrosion A very high temperature above 60 C may evaporate one of the ingredients in Gardolene making the solution less effective Also the high temperature could produce alga like growths in the solution If the bath temperature is very low below 21 C the desired reaction of the bath may not occur The temperature range recommended is 43 52 C The above was a brief description of the purpose and function of each stage of the five stage wash If you wish to acquire more information on any one or all of the pretreatment stages contact your Production Supervisor Troubleshooting When troubleshooting your pretreatment system it is important to remember your troubles may lie with other factors ie the paint itself the metal condition before the blast machine the painters application the shot blast machine cure oven etc As this guide deals solely with pretreatment the following assumptions will be made a The powder paint is fine b The paint booth painters are good c The cure oven is operating properly d There are no airborne contaminants in the plant which could cause paint failures e g silicones When a problem arises it should be looked at in a systematic and logical manner by Identifying the problem Gather all related and seemingly un2. and need changing Possible Solutions a If concentration is low add chemical increase feed 2 3 seconds or if it is very low add manually to get concentration up to target b Check the records to see if the bath is overdue for a clean out Also check the sludge level in the tank and the solution cleanliness Do a phosphate test on the metal exiting the wash to ensure the bath is performing well c Ifthe pH is above the high parameter set plug in the OX M to reduce the pH Run the pump and time for 20 seconds then check the pH Give it enough time to adjust if it is still too high add another 20 seconds worth Quality When adding 714 and OX M so only if you re other solutions do not work Additions of these chemicals to the bath should only be used as last resort as they will affect the bath s effectiveness and age if too much is added 5 Stages 2 and or 4 TDS too high Possible Cause a Baths could be stagnating Not getting enough fresh water b There could be carry over from the previous stage stages 1 or 3 c Incorrect nozzle alignment i e stage 1 nozzles spraying solution into stage 2 d Parts could be extremely dirty cleaning stage and or blast machine not working properly e Tank nozzles could be excessively dirty Possible Solutions 8 13 TECHNICAL TRAINING DEPARTMENT a Increase overflow of fresh water or turn on intake valve and slow drain tank b Check the way the parts are hung
3. bath and then reattach back onto the part The result is a smooth invisible phosphate conversion coating on the surface of the part This process is almost an instantaneous reaction which explains why it can occur in such a short time and in combination with the cleaning function of the stage It simply converts the metal into a passive state that resists corrosion or rusting 10 13 TECHNICAL TRAINING DEPARTMENT This is an extremely delicate balance as too great a concentration of acid will result in too much metal attack and insufficient acid will result in too thin a phosphate coating The pH and temperature are also crucial factors Too low a pH reading very acidic will result in too much metal attack resulting in a very high coating weight This will be evident by a white powdery film on parts coming out of the wash This would result in poor corrosion resistance A very high pH will result in an insufficient phosphate coating and also giving you poor corrosion resistance A very hot bath will cause the reaction to occur at a greater rate and more aggressively giving you heavy coating weights If temperature is too low your reaction will be weak and slow which will result in low coating weights For these reasons you must be extremely careful to monitor your bath closely and keep everything within parameters 2 Stage 2 amp 3 Fresh Water Rinses The following stages are fresh water rinses The purpose of these rinses is
4. parts on the line The abrasive blast machine is tested regularly and Preventative Maintenance performed to ensure everything is working up to its capability Observing parts coming out of the blast machine before entering the wash is the best way to tell if the machine is doing its job They should be free of any rust or mill scale and uniformly silver in appearance 5 STAGE WASH SYSTEM 1 Stage One Cleaning Inpro Clean 1300 Oakite Stage one of our five stage wash is the cleaning stage Inpro Clean 1300 is an alkaline cleaner pH is above 7 00 which means it cleans inorganic soils the best These soils include grease and any oils that may be on the substrate part The purpose of this stage is to get the metal as clean as possible in preparation for the phosphate conversion coating Stage 3 Parameters for concentration pH and temperature must be closely adhered to or the bath simply will not perform its job as well If concentration is slightly high there will be no adverse effect However if concentration is extremely high the parts may not rinse properly and there may be an alkaline residue left on the parts If concentration is extremely low the stage may fail to completely remove all of 1 13 TECHNICAL TRAINING DEPARTMENT the oil or shop oils from the metal surface thereby leaving the metal not clean enough to perform a proper phosphate conversion of the metal in stage 3 TDS is not measured in either this stage o
5. recharge Check the sludge levels in tanks and also the solution appearance e Steel supply Has suppliers or material changed Is it rusty Check the parts exiting the wheelabrator f Has there been any change in the process prior to pretreatment ie lubricant on the steel g Conversion coating problem Perform phosphate test on the metal check with testing solution 47 Failure indicates an inadequate bath or clogged nozzles h Is the coating uniform If not check the nozzles If the nozzles are out of alignment you may get a poor or streaky coating i Check operating parameters of stage 1 Correct if anything is out of parameters j Run some tests using Q panels and B100 panels pretreated panels Poor results on Q panels indicate that the bath needs either adjusting dumping or both k Rinse quality Check operating parameters and adjust if needed Check sludge levels in rinse tank Check nozzle alignment and cleanliness 2 Rusty Parts a pH of stage 1 phosphate may be too high or too low Get it within parameters b Incomplete cleaning Refer to poor adhesion corrosion failures section c Line stoppage Parts trapped in or between stages 12 13 TECHNICAL TRAINING DEPARTMENT d Check pump pressures nozzle alignment and cleanliness in all stages 3 Dusty or Powdery Phosphate Coating a Excessive coating weights pH too low concentration too high in stage 1 i Check operating parameters ii Lower the
6. to ensure there is not carry over of solutions from tank to tank c Do a wash check ASAP Check the nozzle alignment in all stages and correct any misdirected nozzles i Inspect the parts going into the wash for mill scale rust oil or grease Do a water break free test at the end of the wash to check how your cleaning stage is doing e Check the sludge levels on tanks 1 2 and 4 to see if they need dumping and cleaning Also check your nozzles to see if they are plugged or dirty 6 pH Meter will not stay calibrated Possible Cause a Buffers could be contaminated b Meter will easily lose calibration when being used in several different solutions with a variety of pH readings c Improper calibration d Batteries may be weak e Probe may be cracked or worn out Possible Solutions a Make fresh buffers Avoid contamination by rinsing probe well with distilled water between different solutions b Verify calibration and recalibrate if necessary before each set of titrations Ensure you are calibrating the meter properly Using clean correct buffers j Try changing the batteries even if lo batt message does not appear They may be weak e Check the probe for cracks if nothing else works you may have to call Company Maintenance to replace the probe 7 Overspray out of wash entrance or exit Possible Causes a Pressure too high on stages 1 or 5 b Misdirected nozzles in stages 1 or 5 c Exhaust fans not o
7. to wash off any residue of phosphate solution left on the parts and stop any further reaction The rinse water is ambient temperature unheated Two things are very important to watch First the TDS must remain well below 530 PPM to be clean enough to adequately rinse your parts Second you must ensure that your acid contamination stays below 0 6 mls At the beginning of each week a fresh water titration from the tap should be performed so that when you do a wash test you can subtract this number from your answer to get a true contamination reading If you find you are continually getting high TDS and contamination readings there are three things you should check a Risers and nozzles Check your nozzle alignment and cleanliness in all three stages Misdirected nozzles from stages one or three will cause the bath to become contaminated very quickly as well as plugged or dirty nozzles or risers b Overflow The last row of risers in stage two is incoming fresh water and causes continuous overflow in the tank This riser should always be on c Parts on line Check the way your parts are hung on the line If they are holding a lot of solution from stage one and are carrying it into stage two the result will be a high acid contamination in your rinse Always hang your parts to allow excess solution to drain out immediately Troubleshooting When troubleshooting any pretreatment system it is important to remember that problems may al
8. STANDARD OPERATING PROCEDURE PRETREATMENT INFORMATION amp TROUBLESHOOTING GUIDES Pretreatment is just one aspect of a total finishing system Problems with the finished product do not necessarily mean a problem with pretreatment There may be problems with paint quality paint application curing ovens etc Sometimes the problem is a result of two or more aspects of the finishing system as a whole Therefore it is very important that our operators are skilled and knowledgeable enough to recognize and solve problems with the entire system as soon as possible This guide will deal with the problems commonly found in pretreatment parts of a finishing system We will begin with the mechanical cleaning of the metal and end with the parts about to enter the paint booth 1 Mechanical Pre cleaning The cleaning process starts at the abrasive blast machine The abrasive blaster removes rust mill scale and other contaminants such as residues left on and around welds by the welding process It accomplishes this by propelling tiny beads of metal at the part Other systems use sand metal grit glass beads and even walnut shells The abrasive machine has a window of operation which is the area inside the machine where the cleaning is the most thorough and efficient Parts which are hung outside this window very tall parts for example will not be cleaned as well as parts within the window of operation This must be kept in mind when hanging
9. The pH measurement is also extremely important Correct pH is essential for the phosphate action to occur so it must be monitored constantly Too low a pH very acidic will result in too much metal attack resulting in a very high coating weight This will be evident by a white powdery film on the part coming out of the wash This results in poor corrosion resistance A very high pH will result in an insufficient coating weight which will result in premature rusting problems If you stay within parameters you should not have any of these problems Finally temperature is yet another factor in an iron phosphate bath that is critical to the performance of the solution An extremely high temperature will result in dry down on metal surfaces of the parts before they get to the rinse stage This residue would affect paint adhesion A very low temperature will reduce the reactivity of the phosphate solution resulting in less coating and lower coating weights 4 Stage 4 Fresh Water Rinse Following the phosphate stage is another fresh water rinse As with the first rinse TDS for this stage should be well below 530 This rinse washes off any residue of phosphate solution left on the parts and stops any further reaction As with the stage two rinse this rinse s temperature is ambient and unheated although they do rise in temperature as the wash is running because of the warm parts passing through from previous stage If the temperature is quite hi
10. changed to another form rather than depositing a separate and distinct layer on it The result is a smooth invisible phosphate conversion coating on the surface of the part This process is virtually an instantaneous reaction which explains why it can occur in only 1 1 2 minutes the dwell time of this stage It simply converts the metal 2 13 TECHNICAL TRAINING DEPARTMENT into a passive state that now resists corrosion or rusting This is an extremely delicate balance as too great a concentration of acid will result in too much metal attack and insufficient acid will result in too little phosphate coating Controlling the concentration of this bath is extremely important A concentration slightly too high will not affect the coating A very high concentration will leave a white phosphate residue on the metal surface This residue will lessen paint adhesion A very low concentration will not produce an adequate phosphate conversion coat which will result in flash rusting on the metal surface Therefore it is very important to closely monitor the concentration of your phosphate bath A good coating weight is around 45 mg ft with an acceptable range of 25 60 mg ft We send test panels away to be tested for coating weights every 3 months They simply weigh the unpainted and washed panel soak it in an acid bath to remove the phosphate coating and then reweigh the panel to obtain the weight of the coating in milligrams
11. concentration temperature or both iii Check the pH Get it within parameters b Bath needs changing Excessive sludge Check with Maintenance c Too much carryover into stage 2 rinse Check your nozzle alignment and cleanliness in all three stages d Line stoppage or line moving too slow Parts caught in phosphate stage e Incomplete cleaning f Phosphate adhering to dirt particles Check parameters on stage one do a white rag test on parts exiting the wash 4 Increase in Chemical Consumption Low Concentration a Check operating parameters over the past number of weeks If concentration goes very low it requires a large amount of chemical to bring it up to parameters Even fluctuating from lower to upper limits will increase consumption b Chemical is exiting the bath by carryout or increased production i Check nozzle alignment One nozzle out of alignment can waste a lot of chemical This should also be evident by a lowering of pH in stage 2 anda higher acid contamination titration ii Are parts hung properly ie sloped backwards so water drains back into its stage iii Has anew part or product been introduced to the paint line causing increased consumption iv Has production increased recently If so this would explain an increase in chemical consumption Note When adjusting chemical feed use the timers on the pumps Do not bypass these timers by unplugging them 13 13 TECHNICAL TRAINING DEPARTMENT
12. er 1 Foaming stage 2 rinse Possible Cause s a High concentration contamination b Cold solution left sitting for long time without movement c Carry over from stage 1 d Misdirected nozzles from stage 1 Possible Solutions a Add water slow drain the tank b Check concentration and TDS Slow drain if out of parameters c At earliest convenience check alignment of nozzles in stage one Also check how parts are hung on line check for parts holding a lot of water 2 Air bubble in feed pump line Possible Causes e Low feed pump setting f Tote may be low Possible Solutions a Run pump at full speed for a few seconds and work air bubble out of line If the above does not work call Maintenance to have a look at the meter b Change out the tote if it is empty or very low 3 Stage 3 pH too low Possible Causes a Concentration of phosphate may be high b Bath could be new Possible Solutions 7 13 TECHNICAL TRAINING DEPARTMENT a Add some water to raise the pH Keep an eye on your temperature b Add small amounts of 714 60 120 mls until pH is above the bottom end of parameter Monitor frequently to make sure it does not fall again Also keep an eye on the concentration to ensure it stays within parameters c Be patient The pH will rise in operation and once the bath ages a bit if it is new 4 Stage 3 pH too high Possible Cause g Concentration of phosphate may be low h Bath could be used up
13. er fresh water rinse flows to a riser directly after this stage to keep the parts from drying down between stages that also flows into the tank of this stage The TDS total dissolved solids of the tank must be monitored very closely to ensure your rinse water is pure and clean enough to perform effectively There is also an automatic TDS sensor on this stage that will start overflowing the tank when the TDS reaches approx 450 ppm to help keep the water clean A contaminated rinse will leave a residue on the metal surface that will affect the iron phosphate conversion coating in stage 3 3 Stage 3 Phosphate Cryscoat 347 or 547 Oakite The purpose of this stage is to place on top of the substrate a phosphate coating which serves to protect the metal from premature corrosion The conversion or phosphate coating enhances paint adhesion and improves the corrosion resistance of the metal surface under the paint Keeping this solution well within parameters is critical as slightly too high or low pH concentration or temperature measurements can greatly affect the quality of the coating Essentially what happens is the acidic below 7 00 pH usually around 4 75 pH solution attacks the top layer of the substrate and actually removes some of it These metal particles attach themselves to free phosphate acid molecules in the bath and then reattach back onto the part as an insoluble metallic phosphate crystal The surface is being
14. gh there is no adverse effect In fact the higher temperature will help remove the phosphate salt residue on the metal surface A low temperature rinse may not remove the phosphate salts effectively There is a fresh water riser that uses city tap water to rinse the parts directly after this stage to keep the parts from drying down that flows into the tank This also helps keep the TDS from getting too high 5 Stage 5 Sealant Gardolene Oakite Stage Five is a final sealing rinse which essentially removes any phosphate or water salts from the metal surface and fills in the cracks of the phosphate coating This prepares smoothes the surface for painting Once again staying within specified parameters will assure you of the best results Maximum TDS allowed is 530 PPM It is very important to ensure that your TDS stays below 530 or the solution may be too dirty to adequately do the job This stage is also 3 13 TECHNICAL TRAINING DEPARTMENT prone to developing flock which is essentially a smelly alga like bacterial growth in the bath The concentration of this solution must be monitored very closely If the concentration is higher than the set parameter you may get a residue on the parts coming out of the wash This residue would greatly lessen the quality of the paint adhesion and durability If concentration is too low you may see flash rust on the parts because the solution is too weak to completely seal
15. perating Possible Solutions a Check the PSI on the pumps for stages 1 or 5 Turn down if they are above the designated number b Check your nozzle alignment in stages 1 or 5 Ensure that all nozzles on the 3 risers nearest to the entrance exit of the wash are angled toward the center of the wash and none are pointing out of the wash c Ensure fan switch is on if it is call electrical maintenance immediately Note In general when troubleshooting a pretreatment problem check out your most likely cause first and end with your least likely cause Document everything you do so you do not miss any steps 9 13 TECHNICAL TRAINING DEPARTMENT Sample Problem Problem poor white rag test results reject Check 1 Parts coming out of the blast machine is there excessive grease oil rust mill scale etc If so problem may be solved Parts are too dirty to be cleaned adequately by the wash The blast machine is not performing properly Call Maintenance 2 The sludge level in all wash tanks and solution cleanliness in all tanks especially stage 1 One or more tanks may be very dirty and not cleaning rinsing the parts well enough Your parts will only be as clean as the dirtiest part of your pretreatment system 3 Nozzle alignment and cleanliness If the nozzles are out of alignment and parts are getting poor impingement they may be dirty Also if the nozzles and risers are dirty or plugged the solution will be weak o
16. r contaminated A good indication of plugged nozzles will be higher than normal pressure Low pressure indicates missing or worn out nozzles or leaking risers or spray pipes One of the above solutions should solve your problem with poor white rag test results If you cannot solve the problem quickly on your own call your Supervisor and Company Maintenance NOTE If you ever experience a more serious problem that may potentially result in injury equipment damage or rejected parts do not hesitate to call your Production Supervisor and Maintenance immediately 3 STAGE WASH SYSTEM 1 Stage 1 Cleaning Phosphate Crycoat 347 Oakite The three stage wash is a combination cleaning phosphate stage The cleaner and the bath itself is acidic pH is below 7 00 and it cleans organic soils the best Organic soils include dirt and dust but not grease or oil Therefore it is important that the parts going into the wash are free of grease and oil These are inorganic soils and will remain on the parts and if they are painted may cause the coating to fail to adhere or cause other paint problems The other function of this bath is to place on the part surface a phosphate coating which serves to protect the metal from premature corrosion Essentially how this works is the acidic solution attacks the top layer of the substrate and actually removes some of it These metal particles attach themselves to free phosphate acid molecules in the
17. r the phosphate stage Stage 3 TDS stands for Total Dissolved Solids and is a measurement in parts per million of the contamination of the solution In a cleaning or phosphate stage the TDS reading is too high to be measured This is because if a cleaning stage is doing its job properly there will be lots of contamination in the solution In a phosphate solution measuring TDS will give you a reading of the phosphate in the solution and therefore will not be an accurate indicator of contamination Maximum conveyor speed allowed for Inpro Clean 1300 to perform properly is six feet per minute 2 Stage 2 Fresh Water Rinse The cleaning stage is followed by a fresh water rinse to rinse off any alkaline cleaner from the parts and neutralize the pH of the metal to prepare it for the phosphate conversion coating The temperature is ambient there is no heater on this stage An effect of this rinse being at a low temperature is that it may not remove the Inpro Clean 1300 residue on the parts as effectively If the temperature is very high there are no adverse effects In fact the high temperature should help remove any residues on the metal surface more thoroughly It is very important to keep the TDS of this rinse down to well below 530 PPM If not you do not have clean parts going into the phosphate stage which would result in a poor phosphate coating and therefore poor paint adhesion and durability Overflow from stage four anoth
18. related data ie check all equipment concentrations pH etc c List all possible causes and solutions Weigh the options What is the most likely cause solution to the problem Select the most likely solution Act Did this solve the problem If not go back to your list of solutions and try the next best choice Act again If you have exhausted all possibilities call your Production Supervisor Q gt 00 a o w D Whenever there is a problem with too high low concentration or pH for stages 1 3 5 check to ensure the chemical feed pumps are actually pumping chemical To check pull the feed hose from the pump out of the wash tank and see if chemical is coming out of the hose 4 13 TECHNICAL TRAINING DEPARTMENT Safety Do not stand in front of the hose when you pull the hose out of the 5 Stage Wash Tank Wear proper Safety Equipment ie face shield gloves latex chem apron A Rusty parts exiting the wash If the metal is oxidized or rusted corrosion resistance and paint adhesion may be affected The rust severity will vary depending on the cause As soon as you note any large amount of flash rusting corrective action is required Possible Causes Remedies 1 Line stoppages Will result in part dry down between stages which results in flash rust Also if the fog or misting nozzles are not working dry down may occur 2 Sealer concentration too low If the concentration i
19. s too low under the minimum allowable concentration the solution may not be sealing properly and flash rust will form Check your titrations get the concentration within parameters 3 Line speed If line speed is much slower or faster than normal flash rust may occur as a result of either dry down poor phosphate coatings or poor sealer rinse 4 Phosphate pH concentration If either of these factors are too high or too low flash rust may be the result Check your pH and titrations get everything within parameters 5 Nozzles If nozzles are out of alignment plugged or pressures are too low in any of the five stages especially phosphate flash rust may occur This is a result of a discontinuous or thin phosphate coating on the affected parts Doa wash check as soon as possible 6 Rust on parts prior to wash Shot blast machine not doing an adequate job Rust will not be removed in the cleaner stage Therefore it will remain on the parts throughout the wash Check parts coming out of the blast machine for rust Call Maintenance if rust is evident B Dusty White Coating on Parts Loose powdery and non adherent phosphate will not provide adequate adhesion to metal and will reduce corrosion resistance phosphate coating can be easily wiped off Possible Causes Remedies 1 Poor cleaning Check to ensure that the cleaner concentration pressure and nozzle alignment are adequate Also check for plugged nozzles in
20. se the only thing you can do is keep your baths as clean as possible 4 Dirty bath Especially evident in the cleaning and phosphate stages If your bath is old and or dirty you may consume more and more chemical in trying to keep it performing well Check your sludge levels solution appearance and do a water break free test to see if your cleaning stage is working properly Also check the records to see if a dump clean and recharge is due 6 13 TECHNICAL TRAINING DEPARTMENT NOTE If you notice a definite shift up or down from your concentration target on stages 1 3 or 5 act as soon as you notice the trend Do not wait until the concentration is 0 4 below target to change the feed meter setting At that point adjusting the feed meter by two or three seconds will not do much of anything It is similar to letting a car slow down to 60 km hr and then having to punch it to get it back up to 100 km hr It is much easier to get it back up from 90 km hr Similarly you should make adjustments when it is 0 1 to 0 2 below or above target If you do let the concentration get very low you will have to punch it by manually adding enough chemical to raise the concentration back up to target Refer to your parameter chart for the proper amount ie concentration target 3 5 and tank capacity 21 104 litres if your concentration 3 1 then you need to make up 0 4 add approximately 84 litres 21 104 x 004 D Oth
21. so exist with the paint application equipment curing ovens sloppy application by painters etc Because this guide is directed toward pretreatment the following assumptions will be made 1 The paint quality is fine 11 13 TECHNICAL TRAINING DEPARTMENT 2 The application equipment and applicators are working properly and applying the coatings adequately 3 The cure oven is operating properly 4 There are no airborne contaminants in the plant which can cause paint failures ie silicone Whenever a problem arises it should be addressed in a systematic and logical way by 1 Identifying the problem 2 Gather all related and sometimes seemingly unrelated data ie check all equipment List all possible solutions Weigh the options Select the best alternatives ie Most likely cause of solution Act now OH oR Continue this cycle until your problem is solved Keeping the above process in mind here are some common problems that may occur and some possible solutions 1 Poor Adhesion Corrosion Failures a Is there a cleaning problem Perform a water break test on parts exciting the wash The water should not bead on the part b Check stage 3 operating parameters time temperature concentration pH and adjust where needed c Any mechanical or equipment failures Faulty gauges or probes clogged nozzles pumps not working properly etc d Age of the bath Is it time to dump and
22. stage one Tank cleanliness both bottom of tank and bath itself is also an issue If there is excessive sludge and bath is dirty it will not be cleaning adequately Doa water break free test at the end of the wash and also a white rag test to check if cleaner is performing well 2 Excessive phosphate coating weight Check the concentration of your phosphate bath it may be high Also check the temperature It may be high 5 13 TECHNICAL TRAINING DEPARTMENT as well Usually if your concentration is high in a phosphate solution your pH will be low which would also cause increased coating weight the more acidic the solution the more aggressive it is Lowering the concentration by turning down the feed and or adding fresh water should take care of the problem This will also lower the temperature which may also be a factor The hotter the solution the stronger and faster the reaction therefore greater coating weight 3 Dirty or old phosphate bath If there is excessive sludge on the bottom of the tank the result may be a loose powdery phosphate coating Check the bath for sludge build up It may need to be dumped cleaned and recharged Call Maintenance 4 Stage four rinse may be dirty If there is too much chemical carry over from the phosphate stage into stage 4 you could get this problem Check your acid contamination and your TDS Slow drain or dump and clean tank if contamination greater than 0 6 or if
23. the TDS is higher than 530 ppm 5 Line stoppage Sometimes if there is a long line stoppage the parts caught in the phosphate stage will get an excessive coating resulting is a loose powdery film Check parts carefully after any line stoppages and check your line speed to see if it is much slower than usual Always try to avoid stopping the line unless it is absolutely necessary C Increased Chemical Consumption Low Chemical Concentrations Possible Causes Remedies 1 Nozzle alignment One nozzle out of alignment can waste a lot of chemical and increase your contamination in other stages Check all of your nozzles to ensure they are properly aligned in all stages 2 Increased production Has there been a notable increase in the amount of parts going through the wash If so you may have solved the problem Increased parts increased chemical consumption Continue to check all other possibilities to rule out a problem 3 Carry over Drag out If parts are hung on the line in such a way that they hold a lot of wash solution there will be excess carry over into the next stage This will result in increased chemical consumption low concentration and cross contamination of your baths Check to see that your parts are hung in the best possible position for drainage Also if there is an increase in line speed there will be more carry over than usual as the parts have less time to drain before passing into the next stage In this ca
Download Pdf Manuals
Related Search