ZINCPAS BL 160
TRIVALENT BLUE CHROMATE PASSIVATE FOR ZINCZINCPAS-BL-160 IS A CLEAR BLUE CHROMATE PASSIVATION PROCESS BASED ON TRIVALENT CHROMIUM AND DESIGNED TO PROVIDE TWO TO THREE TIMES BETTER CORROSION RESISTANCE AS COMPARED TO CONVENTIONAL HEXAVELENT BASED BLUE CHROMATING PROCESS.
FEATURE BENEFITS :
CONTAINS NO HEXAVALENT CHROMIUM REDUCES WASTE TREATMENT ANDDISPOSAL COSTS.
CONSISTENTLY PRODUCES MINIMUM REJECTION AND HIGH BLUE-BRIGHT FINISH PROFITABILITY
LONGER BATH LIFE AND EXTENDED INCREASES PRODUCTIVITYDUMP FREQUENCY
PROVIDES HIGHER CORROSION RESISTANCE EXTENDS THE USEFUL LIFE OF PLATED COMPONENTS
USES EXISTING EQUIPMENT AND PROCESS NO EXTRA EXPENSES AND EASY CYCLE TO CHANGE OVER
EQUIPMENT :
TANK-STEEL TANKS LINED WITH POLY-ETHYLENE,POLYPROPLENE OR PVC ARESUITABLE FOR CONTAINING THE PASSIVATION SOLUTION.
AGITATION-FOR RACK PLATING, AGITATION OF THE PART OR SOLUTION AGITATION IS RECOMMENDED FOR GETTING UNIFORM RESULTS. PVC OR POLYPROPLENE COILS ARE TO BE USED.
SOLUTION MAKE-UP :
FILL THE TANK WITH 3/4 OF ITS VOLUME WITH WATER AND ADD THE MEASURED QUANTITIES OF ZINCPAS-BL-160 AND STIR THE SOLUTION WELL ADD MORE WATER TO MAKE UP THE LEVEL MEASURE THE PH AND ADJUST TO 1.6 TO 2.0 BY ADDING NITRIC ACID.
OPERATING CONDITION :
ZINCPAS-BL-160 50-80 ML/LIT
NITRIC ACID (42BE.DEG) 1.0-2 ML/LIT.
SOLUTION PH(ELECTROMETRIC) 1.8 – 2.2
SOLUTION TEMPERATURE ROOM
IMMERSION TIME 20-30 SECONDS
PRE AND POST TREATMENT :
IT IS ADVISABLE TO RINSE AND CHROMATE PASSIVATE THE PLATED COMPONENTS IMMEDIATELY AFTER ELECTROPLATING AND WE RECOMMENDED TO HAVE AN ACTIVATION STEP BY USING 2.0-3.0 CC/LIT NITRIC ACID.THE PASSIVATED PARTS MUST BE RINSED USING COUNTER FLOW RINSE AND SUBSEQUENTLY DRIED USING WARM AIR.
TO IMPROVE FURTHER THE CORROSION RESISTANCE OF THE CHROMATED PARTS THESE SHOULD BE GIVEN A PROTECTIVE COATING BY USING MAHA GUARD WATER SOLUBLE LACQUER.
MAINTENANCE :
THE OPERATING SOLUTION CAN BE MAINTAINED AT ITS BEST BY ADDING REGULARADDITIONSOFZINCPAS-BL-16-AND DILUTE NITRIC ACID FOR PH ADJUSTMENT. THE ADDITIONS SHOULD BE GENERALLY BASED ANALYTICAL CONTROL UNTIL A REGULAR MAINTENANCE SCHEDULE HAS BEEN ESTABLISHED.
THE REPLENISHMENT CAN BE MADE ON THE BASIS OF SURFACE AREA PROCESSED AND AS A ROUGH GUIDE ZINCPAS-BL-160 CAN BE MADE AT THE RATE OF 10 ML PER LITRE AFTER WORKING 100 SQ.CM. PER LITRE (10SQ.FT.PER ITR).
ANALYTICAL CONTROL :
REAGENTS NEEDED
0.1 N SODIUM THIOSULPHATE SOLUTION
10% POTASSIUM IODIDE SOLUTION
0.5% STARCH INDICATOR
CONCENTRATED SULPHURIC ACID
AMMONIUM PERSULPHATE
APPRATUS REQUIRED :
50 ML BURETTE : ONE
250 ML ERLEMEYER FLASK : TWO NOS
100 ML GRADUATED CYLENDER : ONE
25 ML PIPETTE : ONE
PROCEDURE :
1) PIPETTE 25 ML OF THE SAMPLE TO BE ANALYSED INTO A 250 ML
ERLEMEYER FLASK AND ADD 100 ML DISTILED OR DEIONISED WATER.
2) ADD 3-5 ML CONC.SULPHURIC ACID, 2GMS AMMONIUM PERSULPHATE AND IF CHLORIDE IS PRESSENT IN THE SOLUTION ADD 10 ML OF 10% SILVER NITRATE SOLUTION.
3) BOIL GENTLY FOR 20-30 MINUTS UNTIL THE SOLUTION COLOUR SHOULD CHANGES TO YELLOW WITHOUT ANY TRACES OF GREEN OR BLUE COLOUR.
4) COOL THE SOLUTION TO ROOM TEMPERATURE AND ADD 20-30 ML OF 10% POTASSIUM IODIDE SOLUTION TO THE FLASK.
5) TITRATE WITH 0.1 N SODIUM THIOSULPHATE SOLUTION TO A LIGHT YELLOW COLOUR AND FEW ML OF STARCH INDICATER AND CONTINUE TITRATING WITH THE SOLUTION CHANGES TO LIGHT GREEN COLOUR.CALCULATION :
ZINCPAS-BL-160 G/LIT = V X N X 25.5WHERE V = ML OF THIOSULPHATE USED FOR TRITRATING.N = NORMALITY OF THE SODIUM THIOSULPHATE SOLUTION