Fixing Excessive Brightener Consumption From Dull Work In Alkaline Non-Cyanide Zinc

As published in Products Finishing Magazine, October 2019 issue.

Q. During the summer months as the temperatures have risen in the plant, we’ve been seeing an ever increasing dropoff in brightness of our alkaline zinc line. Even adding significantly more product than normally prescribed dosages has been somewhat ineffective in restoring overall quality. How do we maintain process performance and achieve the finish our customers expect while staying cost effective?

A. Although great strides have been made over the last 30 years in the development of alkaline non-cyanide zinc processes that deliver a bright and ductile deposit, yet remain robust, durable and easy to operate, the truth is that not all “modern” systems are created equal. Many still utilize volatile chemistries that, while relatively low cost, have much narrower operating windows. These materials can be consumed at exponentially higher rates at elevated temperatures and may also cause these chemistries to produce breakdown products that become a nuisance to remove from the plating solution and tank walls. The most common of these particular brightening agents are aldehyde and/or derivatives. It is from this group that the aforementioned complications arise. Read more.