Trivalent Chrome Silverish Blue Passivation for Zinc Plating process

 Trivalent Chrome Silverish Blue Passivation for Zinc Plating process

Tripass SB 200

 Introduction: 

■ Tripass SB 200 is a unique Tri-chrome passivation technology that produces “Blue-White finish 

on Zinc Plating. This passivation can produce bright, haze-free “blue-white” colors including 

blue, metallic and clear shades with a range of thickness from 50-100 nm. 

■ The color is determined by the thickness of the passivation and controlled by the chemical 

concentration, pH, temperature, solution agitation and immersion time in working bath. 

■ These parameters determine the reaction rate and thus the color and thickness of the passivate.

■ Tripass SB 200 has demonstrated good color control and corrosion resistance (NSS) as a function 

of bath aging. It is capable of meeting current automotive standards and ROHS directives. 

Key Features:

■ TRIPASS SB 200 is Tri-chrome passivation chemistry, free of hexavalent chrome

■ Excellent corrosion resistance

■ Blue-White Colors: Clear - Metallic, Blue

■ Good tolerance to Zinc and Fe contamination

■ Single Component System

■ Wide Operating Window

■ Suitable for both Barrel & Rack applications

■ Relatively low cost of ownership

Make Up Procedure: 

■ Add 60 Ltr of DM water and heat to 30°C. 

■ Add Slowly 5 Ltr of TRIPASS SB 200 while agitating the solution.

■ Add 35 Ltr of remaining D M water. Continue to heat and agitate the solution.

■ Measure pH value and in case not in within range, adjust to 2.2 by adding 10% sodium hydroxide 

solution or 30% diluted Nitric Acid until value reaches 2.2 or desired pH (adjust pH meter to 

compensate for temperature of 30⁰C).

■ Adjust volume to 100 Ltr with D M Water.

■ Once the pH value and volume are adjusted, The solution is ready for operation.

Impurity:

TRIPASS SB 200 is tolerant of zinc and iron impurities from bath operation, and thus extends the 

lifetime of working bath. The relatively low concentrations of chrome (III) and cobalt constituents, 

the low operating temperatures and long bath life result in low cost of ownership for the customer. 

TRIPASS SB 200 is also environmentally friendly because it is chromium (VI) free which facilitates 

wastewater treatment.

■ Zinc Changes in appearance and a decrease corrosion resistance can be expected at 10 - 15 

gm/Ltr Zinc in working bath. A new bath make-up is highly recommended

■ Iron Changes in appearance are expected at 100 to 200 ppm. 

■ Copper: Decrease in salt spray resistance can be expected ~5 ppm.

Replenishment:

TRIPASS SB 200 is replenished to approximately 0.15 ml/dm2

(0.12 - 0.18 ml/dm2)

Quantitative analysis of Chrome content by ICP/AAS should be made periodically to ensure

optimum working bath concentration. A mixture of TRIPASS SB 200 and 50% v/v of concentrated 

nitric acid to a ratio of 1:1 is added to adjust Chrome concentration. 

Note: The actual replenishment amount is affected by the total dm2 throughput and drag-out rate. 

This needs to be determined explicitly at each individual customer installation. 

Maintenance:

The higher concentration of TRIPASS SB 200 temperature, solution agitation and specific type of 

zinc deposit may increase the reaction rate and thickness of passivation films. The color will change 

from metallic blue-white / clear to blue.

pH value adjustment down by 30% v/v nitric acid solution. pH values <1.8 result in an overactive 

passivation solution and are not recommended. Too low pH value result in reduced bath life due to 

high amounts of zinc dissolution. pH adjustment up are made with a 10% NaOH solution.

Agitation:

■ The light air agitation required for the rack application. It should be uniform. The mechanical

agitation will be used along with the centrifugal circulation pump.

■ For Barrel application, the sufficient rotation of the barrel.

Equipment:

TRIPASS SB 200 is an acidic in nature, therefore we must use acid resistant material like as PVC, PP

or plasticized steel. The use of proper temperature controls and air agitation is suggested.

Waste Disposal & Handling:

The preparation, maintenance, and disposal of TRIPASS SB 200 solutions require the handling of

concentrated trivalent chrome containing chemicals. Additionally, concentrated alkali and/or acid

may be required for pH adjustment purposes. Avoid contact with the skin and eyes. Wear protective

clothing and safety gear. In the event of any contact, flush affected area with a large volume of cold

water and contact a physician, if necessary

First Aid:

After contact with skin, take off immediately all contaminated clothing, and wash immediately with

plenty of water. After contact with skin, wash immediately with plenty of water. In case of contact

with eyes, rinse immediately with plenty of water and seek medical advice. If swallowed, seek

medical advice immediately and show container or label.

Shelf Life:

The shelf life of the product is two year from the date of manufacturing.

Product Information:

Product Name

TRIPASS SB 200

Specific Gravity

1.22-1.24

Disclaimer of responsibility:

The data set forth in this bulletin is believed by SURCURE TECHNOLOGY  to be true, accurate, and complete, but is not guaranteed. Our

sole warranty is as stated in our Standard Terms and Conditions of Sale. We cannot warrant that our customers will achieve the 

same results from any process, chemical or product described in this bulletin because we do not have control over the conditions 

of use; nor can we assume any responsibility for our customer's use of any of our products in a manner which infringes the 

patents of third parties.