Proses pelapisan seng dengan menggunakan logam seng sebagai anoda terhadap logam ferro, merupakan salah satu cara untuk melindungi logam tersebut terhadap serangan korosi, dan menambah keind…Deskripsi lengkap
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zinc plating
ASTM B733 Electroless Nickel Plating
msds
The first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865. The German chemists Fittig and Paul discovered in 1877 the polymerization pro…Full description
DEVECO A c i d Z Zi n c C Ch l o r i d e Tr o u b l es h o o t i n g C Ch ar t Problem
Possible Cause Cause High pH Low ammonia or chloride Low Brightener
Dullness in LCD area (1 to 20 ASF)
High operating temperature High Iron Contamination (>100 PPM) High Brightener High operating temperature High pH
Dull or poor cov erage in MCD to LCD area
Low wetter Low Brightener High operating temperature Low Brightener
Dull deposit in entire current density range
Poor surface preparation No response to brightener, may indicated organic contamination Bath has high temp & low cloud pt. (< 115 F) High pH Over-addition of Hydrogen Peroxide Low Zinc metal Low ammonia, boric acid or chloride
Burning and/or soft spongy deposits in the High Current Density area
pH too high or too low Brightener too high. Wetter extremely high or too low. Work too close to anodes, poor agitation Low operating temperature Current density is too high Low Chlorides Low Wetter High Zinc metal
Poor throwing power No deposit in LCD area
Over-addition of Hydrogen Peroxide High pH Chromium contamination (>200 PPM) High Brightener
Solution Check and lower with 50% Hydrochloric Acid Analyze and adjust into range Run Hull Cell. Add 0.05% increments to optimize deposit Lower to recommended range Hydrogen Peroxide treat. Add ¼ - ½ pint 35% H2O2 per 1000 gal. Dilute H2O2 at least 3:1 with water. The precipitated Ferric Hydroxide is filtered out Contact Deveco representative Lower to recommended range Check and lower with 50% Hydrochloric Acid Run Hull Cell. Add 1% increments to optimize deposit Run Hull Cell. Add 0.05% increments to optimize deposit Lower to recommended range Run Hull Cell. Add 0.05% increments to optimize deposit Improve cleaning, pickling and/or rinsing. Circulate solution through a carbon filter or batch carbon treat Add 1 – 2% Deveco Zinc Clarifier, and/or Cool solution to proper operating temp. Check and lower with 50% Hydrochloric Acid Leave air agitation on to help dissipate the H2O2. Add up to 100 mls Brightener/100 gals solution. Analyze and adjust into range Analyze and adjust into range Check and slowly add 50% HCl to lower it or 45% KOH to raise it. Run Hull cell and adjust as needed. Check and adjust racking and air patterns Raise temperature above 65 F Check the rectifier and check the calculation Analyze and adjust into range Run Hull Cell. Add 1% increments to optimize deposit. Up to 3% total. Lower to 2.5 oz/gal Zinc Leave air agitation on to help dissipate the H2O2. Add up to 100 mls Brightener/100 gals solution. Check and lower with 50% Hydrochloric Acid Add 1.0 oz Sodium Hydrosulfite/100 gal soln for every 100 PPM of chrome in solution. Reduce brightener additions or cut the bath per Hull cell tests.
DEVECO A c i d Z Zi n c C Ch l o r i d e Tr o u b l es h o o t i n g C Ch ar t Problem HCD areas dark er after nitric dip or chromate dip.
Black staining in LCD areas aft er chromating
Possible Cause High Iron contamination (> 100 PPM} High organic contamination.
High Metallic contamination Copper > 5 PPM Lead > 5 PPM Cadmium > 10 PPM High Additives
White staining or poor chromate appearance
High pH Filter not working properly
Check intake, discharge and pressure.
High temperature
Lower to recommended range.
Poor rinsing
o
Cloud point below 100 F
High Iron contamination
High Chlorides Brittle zinc plating
Check tank bottom of tank for parts. Hydrogen Peroxide treat. Add ¼ - ½ pint 35% H2O2 per 1000 gal. Dilute H2O2 at least 3:1 with water. The precipitated Ferric Hydroxide is filtered out Analyze and adjust to range.
Filter not working properly. Low anode area
Check anode baskets or anode slabs.
Poor rinsing and/or cleaning Low wetter
Chrome contamination (>200 PPM) Poor adhesion of zinc
Add 1 – 2% Deveco Zinc Clarifier.
Reduce brightener additions or cut the bath per Hull cell tests. Check intake, discharge and pressure.
High Brightener
Anode particles Rough deposit
Check tank bottom of tank for parts. Hydrogen Peroxide treat. Add ¼ - ½ pint 35% H2O2 per 1000 gal. Dilute H2O2 at least 3:1 with water. The precipitated Ferric Hydroxide is filtered out LCD dummy the bath at 2 – 5 ASF for 8 – 12 hours. Or zinc dust treat at 1 lb zinc/1000 gallons of solution to remove 10 PPM trace metals. Filter out the zinc particles so they don’t redissolve into the bath, Reduce wetter and brightener adds Dump and rebuild rinses. Add ½ fl oz./gallon Hydrochloric Acid to the first rinse after zinc plating. Use 2 oz/gal Citric Acid dip in place of nitric acid. Run Hull Cell test Add 1% increments of wetter to optimize deposit. Check pH and lower with 50% HCl
Brightener too high or wetter too low
Cloudy turbid solution
Solution
Poor cleaning
Check anode bags for tears and/or holes. Filter solution Improve rinsing, cleaning and/or pickling Run Hull Cell test Add 1% increments of wetter to optimize deposit. Add 1.0 oz Sodium Hydrosulfite/100 gal soln for every 100 PPM of chrome in solution. Filter solution. Check for proper preparation and cleaning of work.
