One of the biggest challenges facing local governments involves providing safe and clean drinking water to residents. This proves particularly challenging for a place like Florida, situated between saltwater bodies and on top of swamps. For as long as I’ve been in Florida, I’ve always used filters to remove excess contaminants from drinking water. However, the city of Tampa ranks among the state’s best at providing contaminant-free water to its residents. Now, Tampa aims to provide even higher quality water, teaming up with a Dutch company, PWNT Water Technology. PWNT employs an ion exchange water system that also happens to provide a patent cautionary tale for inventors.

PWNT’s system, named the SIX®, or Suspended Ion Exchange, dissolves organic carbon molecules in water. The system employs resin to bind to the carbon molecules, which then settle at the bottom of a reservoir. The carbon then detaches from the resin and flushes from the reservoir. Importantly, the resin can be reused for multiple binding and removal processes; as such, the SIX® improves the efficiency of removing carbon-based contaminants.

Cautionary Tale – Prior Publication Can Doom Patent Application

What makes PWNT a patent cautionary tale, though, is found in its United States patent application. The company filed the US application in 2014 and claimed benefit to a Netherlands-based application from 2012. After over two years of prosecution, receiving and overcoming rejections, the path to patentability looked promising. However, the USPTO examiner found a publication that disclosed almost every aspect of the invention. The publication happened to be from the company itself, years before it filed the Netherlands patent application. Since the company previously disclosed the majority of the invention well before the priority date, the patent application didn’t stand a chance.


As such, the SIX® patent application serves as a cautionary tale for inventors. Any publication can serve to block a future patent from issuing; this particularly includes an inventor disclosing his/her own work. Often, waiting on publication until figuring out the patent landscape is the optimal plan to preserve patent rights.

Do I have to get a patent to sell my product?

No – you can sell products without patent protection, but others can make and sell the same product.

Did PWNT obtain any intellectual property protection?

Yes – SIX is a registered trademark.