SEALER 700 W PHYSICAL PROPERTIES: Clear, colourless, ph neutral liquid DESCRIPTION: SEALER 700 W is a water dilutable, inorganic sealing system based on silicon. SEALER 700 W contains no chromates in the dry film and does not produce hydrogen embrittlement into the coated material. The layer is transparent. SEALER 700 W is an inorganic sealing system which reacts with all our passivations on top of zinc or zinc alloys. Corrosion protection of more than 1000 hours in salt spray test according to DIN 50021-SS or ASTM B 117 without base metal corrosion can be reached. SEALER 700 W improves corrosion resistance according to VDA 621-415 alternating atmosphere test compared to unsealed and conventionally sealed products. SEALER 700 W achieves a coating thickness between 0.5 and 1 microns on rack parts. SEALER 700 W improves significantly corrosion protection according to condensed water containing climate DIN 50017 and out door exposure (weathering). SEALER 700 W increases temperature resistance up to 200 C depending on use. J. Unger Rev 2 21.12.2005 1/6
DELIVERY CONDITIONS: Density 1.07-1.15 g/cm³ Solid content 18-22 % ph value 6-8 Theoretical coverage rate Stability 150 300 m²/kg at 0.5-1 µm coating thickness depending on concentration and drag out. 6 months in original sealed drums at 20 C. Frost-free storage recommended. APPLICATION METHODS FOR CENTRIFUGE PARTS: Make-up 50-100 % Dip time 5-30 s Temperature 20-30 C Thinner Demineralised water, conductivity max. 20 µs APPLICATION METHODS FOR RACK PARTS: Make-up 30 % 20-50 % Dip time 60 s 60-120 s Temperature 50 C 40-60 C Thinner Demineralised water, conductivity max. 20 µs ph value 5-7 The. ph value should be adjusted by partial new make-up from sealer concentration. J. Unger Rev 2 21.12.2005 2/6
EQUIPMENT FOR RACK PARTS: Filtration Circulation Heaters Movement Dosage Hang over time Fade equipment 5 10 µm filter approx. 1 times per hour Necessary Not necessary, avoid air blowing Depending on cycles, according to drag in and drag out. Concentration should be determined by analysis of solid content. 30-90 s Depending on parts and requirements RINSING Optimum rinsing maintaining constant quality of sealer requires a rinse criterion of 1000 between passivation and sealer. After passivation 2 or 3 flow rinses should be used before racks are dipped into sealing tank with. A spray rinse as final rinsing also avoids drag out and passivation components affecting corrosion protection of the sealing. BATH CONTROL / CONCENTRATION Solid content can be determined following details on page 6 or according to DIN EN ISO 3251 or DIN 53216. A quick and easy determination can also be made with the Halogen Moisture Analyzer (e.g. Mettler Toledo HB 43). The sealer concentration should be checked regularly. To increase the sealer concentration add 10 ml/l SEALER 700 W for 1%. Analysis of chrome content can be made by atomic absorption spectroscopy. J. Unger Rev 2 21.12.2005 3/6
CURING CONDITIONS: Air circulated Box Oven 25 min at 50 C object temperature 18 min at 80 C object temperature 10 min at 120 C object temperature Object temperature should be controlled by oven curves with data log. WASTE DISPOSAL: Liquid should be further diluted before discharge to meet local authority laws. SAFETY PRECAUTIONS: See Material Safety Data Sheet GUARANTEE: Above instructions and recommendations are the results of intensive testing and shop experiences. They are for your information, only. Our guarantee extends to the continuous quality of our products as they leave our factory and not to their usage in the field which is a factor beyond the control of a supplier. J. Unger Rev 2 21.12.2005 4/6
TROUBLESHOOTING: PROBLEM CAUSES CORRECTIONS Excessive drying deposits Insufficient corrosion protection Heterogeneous or matt sealer surface Concentration too high Temperature of sealer too high Unfavorable hanging position of parts Insufficient fade equipment Concentrat too low Temperature too low Contamination of sealer Low ph value by drag in of passivation Dip/hang over time too short Fade equipment too strong Incorrect passivation Poor drying quality Precipitation of sealer by ph displacement due to insufficient rinsing High drag in of passivation Adjust concentration Reduce temperature Adjust hanger to parts size Improve fade equipment Adjust concentration Increase temperature Analyse foreign metal Improve rinsing and raise ph by partial new make-up Extend dip/hang over time Reduce fade pression Adjust passivation Check object temperature and increase drying temperature and time Improve rinsing and raise ph by partial new make-up Improve rinsing J. Unger Rev 2 21.12.2005 5/6
DETERMINATION OF SOLID CONTENT OF SEALER 700 W Description of Test Method: At all times a double weight determination has to be done. The determination of the solid content of the has to be done at a temperature of 180 C for 30 minutes in an oven. Required Equipment: Analytical balance 0.001 g sensitivity Oven to work at 180 C Petri capsule 20 cm² surface, approx. 50 mm diameter Desiccator Test Method: Adjust the balance to zero. Check the weight of the Petri capsule. Weigh an amount of 1 5 g of onto the Petri capsule. (The value of the weight should be determined with accuracy.) Put the Petri capsule with the directly into the oven at 180 C for 30 minutes. Transfer the capsule to the desiccator and let it cool down until it reaches 20 25 C. Weigh the capsule with the dry extract correctly. Calculation: % Sealer = Factor = 5,0 Weight of extract of Weight of x 100 x Factor J. Unger Rev 2 21.12.2005 6/6