NaOH Concentration Measurement in Aluminum Extrusion

When extruding aluminum, the dies used for forming will collect residual material and other contaminants that build up over time. Too much build-up can cause imperfections in future extrusions and lead to non-conforming finished product. To correct this issue, the dies are periodically removed from the extrusion line and cleaned in a NaOH bath. Regularly, operators pump NaOH at 50% or higher concentration into a storage tank and then add it to the bath to start the cleaning process. End users can typically reuse NaOH to about 15-20% concentration. After that, they will need to dispose of the spent Sodium hydroxide.

Conductivity sensors are typically used for concentration measurement. Without a conductivity measurement, the operator could inadvertently use NaOH that’s too weak and not clean the dies properly. Also, without accurate concentration information, it’s possible they could dispose of NaOH that is still effective. Whether due to lost product or overuse of cleaning solutions, the user will lose production time and money.

Our Concentration Solution

M4 Knick achieves accurate and reliable conductivity measurements utilizing the Knick SE 655 Memosens conductivity sensor in applications ranging from pure water up to 2,000 mS/cm. The SE 655 is a corrosion-resistant, toroidal-style conductivity sensor, with smooth, easy-to-clean construction. The SE 655 is highly accurate due to the use of the inductive measurement principle. The large sensor opening ensures a low risk of contamination. The sensor is suitable for hazardous locations. A Knick Stratos or Protos transmitter displays the conductivity measurement as % Concentration of NaOH when paired with the SE 655 sensor. This is a well-established industry practice.

Using a Knick conductivity loop gives the end-user the ability to confirm that NaOHs suppliers are meeting product specifications of 50% or higher concentration. Additionally, they can verify the effectiveness of the NaOH used for die cleaning and get the maximum use out of their NaOH before disposal.

Other industries NaOH concentration measurements:

  • Power generation
  • Steel Manufacturing
  • Pulp & paper
  • Food & beverage
  • Refining
  • Petrochemical & specialty chemical

What was this Customer’s Return on Investment?

Eliminates weak NaOH in the System: Prevents the use of weak NaOH for cleaning ensuring there are no quality inspection failures or product loss.

 Reduces Maintenance Costs: The SE 655 toroidal conductivity sensor performs well in difficult process conditions and requires fewer calibrations due to the all PEEK inductive design and construction.

Improves NaOH Vendor Quality Control: Eliminates returned shipments of NaOH due to being out of specification. The customer can identify out of spec NaOH deliveries and take action to reduce downtime as a result.

Products Featured in this Application

Stay in the loop and join our newsletter

Join the Loop, M4 Knick’s exclusive newsletter, for access to content regarding industry trends, product highlights, and more!

NaOH Concentration Measurement in Aluminum Extrusion