How to Measure PTFE in an Electroless Nickel Bath

Описание: Electroless nickel with PTFE, or Teflon, is an advanced coating with low friction and release performance benefits on parts used in countless industries around the world.
One of the key parameters to ensure the optimal application of this coating is proper maintenance of the PTFE concentration in the electroless nickel plating bath.
This video shows a reliable method to measure the PTFE concentration for coating consistency, quality, and bath life.
The materials needed and specific procedure are included below.
For more information on this process or any aspect of electroless nickel with PTFE or other materials, please contact Surface Technology, Inc. and see:
www.surfacetechnology.com
www.one-plate-en.com
www.en-247.com

MATERIALS NEEDED

• Millipore filter paper, No. HVHP 047 00, pore size 0.45µ or equivalent
• S&S filtering apparatus, No. GV 050/0 or equivalent
• Vacuum flask using No. 8 rubber stopper
• 25cc pipette, or graduated cylinder
• Scale to weigh accurately to 0.1 mg
• Vacuum pump or water aspirating unit for spigot

PROCEDURE

1. Pre-weigh one piece of filter paper from above and record weight (W1).
2. Place filter paper in the S&S glassware and apparatus described above.
3. Attach filtering apparatus with filter paper to vacuum flask and turn on vacuum.
4. Pre-wet the filter paper with several ml of isopropanol.
5. Rinse with DI water
6. Using a 50ml volumetric pipette, pipette 50ml of the PTFE bath (while insuring that the bath is agitating so that the sample is representative of the entire bath, and the total quantity of PTFE is actually suspended in the bath.), into the above-mentioned apparatus.
7. Rinse particles on the filter paper with DI water.
8. Rinse the pipette and sides of all glassware into the vacuum funnel and onto the filter paper.
9. Rinse the filter paper with a small amount of isopropanol.
10. Carefully remove the filter paper from the apparatus and place it onto a glass petri dish and dry the substrate at about 75-80°C for at least 15 minutes or until weight loss ceases.
11. Cool in a desiccator.
12. Weigh the filter paper and PTFE residue (W2)

CALCULATIONS

ΔW = W2 – W1 = Weight of PTFE powder

Dispersion in bath (g/l) = ΔW x 33.3 (g/l)

Replenishment per gallon NiSlip or One-Plate bath

Replenish the bath as follows:

Grams of Dispersion to add to the bath = [5 – (ΔW x 126)] x number gallons of bath