Zinc
MAR ZINC TRIBLACK PASS
The MAR ZINC TRIBLACK PASS is a unique easy to use all trivalent black passivation coating that can be applied to electrodeposited barrel or rack zinc/nickel. MAR ZINC TRIBLACK PASS produces a comparable finish to hexavalent black conversion coatings when used in conjunction with newly developed sealer such as the MAR ZINC PRO SEAL BLK. This system complies with the European ELV directive and further environmental RoHS and WEEE directives. The finish further meets the RoHS requirements of China. The passivated coatings generated with MAR ZINC TRIBLACK PASS are temperature stable up to 200°C, so all parts can be coated before treatment for hydrogen embitterment.
The MAR ZINC TRIBLACK PASS is two-part system with long bath life and easy control. When sealed properly, it will exceed 96 hours of 5% neutral salt spray before the appearance of white corrosion products. MAR ZINC TRIBLACK PASS can be operated at ambient temperatures.
OPERATING PARAMETERS
| RANGE | RECOMMENDED | |
| MAR ZINC TRIBLACK PASS PART A | 40 – 60 ml/litre | 50 ml/litre |
| MAR ZINC TRIBLACK PASS PART B | 40 – 50 ml/litre | 50 ml/litre |
| pH | 1.6 - 2.4 | 1.8 |
| IMMERSION TIME | 30 - 1200 seconds | 40 Seconds |
| TEMPERATURE | 18 - 30°C | >= °C |
pH should be determined via calibrated pH meter. pH papers are not usually accurate
WARRANTY AND DISCLAIMER: This information is based on our experience and is, to the best of our knowledge, true and accurate. MAR-Tech Holdings Inc. gives no warranty, expressed or implied and the products are sold upon condition that the purchasers will make their own tests to determine the quality and suitability of the product. Any information or suggestions are given without warranty of any kind and the purchasers are solely responsible for any loss arising from the use of such information.
SOLUTION MAKE UP
- Be sure the tank being used is leached of all hexavalent chromium products before charging.
- Fill tank to approximately 60% of final volume preferably with deionized water.
- Add the required amount of MAR ZINC TRIBLACK PASS PART A.
- Add the required amount of MAR ZINC TRIBLACK PASS PART B.
- Bring tank to final working volume and check pH of the solution.
- To raise the pH, use dilute Sodium Hydroxide, and to lower the pH use Sulphuric Acid.
PROCESSING CYCLE
- ZINC/NICKEL PLATE
- RINSE.
- RINSE
- MAR ZINC TRIBLACK PASS
- RINSE
- RINSE
- RINSE
- SEALER
- DRY AT 160 OF – 180 OF.
Routine additions via metering pump or regular "over the side" tank additions should be incorporated into the operating procedures. It is not wise to allow the solution to become almost depleted and "recharged" with large amounts of chemistry. Addition rate should be determined empirically through analysis of the passivation bath with a correlation of the amount of work going through the line. Typical replenishment rate of 1 litre MAR ZINC TRIBLACK PASS PART A for every 100 – 150 square feet of work being processed should be used as a guide. Part configuration and drag out should be taken into consideration when determining the exact add back rate.
| Tank material: | Steel with rubber coating or liner made of polyethylene or polypropylene, PVC, PVC / polyester composite |
| Heating: | A heater is required in some cases. Suitable heating elements are made of tempered glass, Porcelain, PTFE or exchanger from stainless steel or tantalum |
| Cooling: | In some cases, cooling is required. |
| Temperature control: | This is necessary in some cases. In the case of thick layer passivation the quality of the coating is depending on the bath temperature. |
| Electrolyte movement: | It is important to ensure that the goods are well washed with the passivation solution. Therefore, an air or goods movement is recommended. |
| Exhausting: | Recommended. |
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