A New Innovation in Coatings

摘要

For a number of decades the de-ionization of water has been accomplished with polishing and mixed beds vessels lined with rubber or some type of elastomeric lining. These linings, though inexpensive and widely used, suffer from a number of difficulties and challenges. They have relatively short life spans and high levels of extractables and TOC levels. Joint failure, blistering and disbonding of the elastomeric lining is not uncommon. Because of these challenges device manufacturers and their suppliers seeking higher purity water began using fluoropolymer sheet linings. Though the water quality improved exponentially the linings were expensive and difficult to install. The next development in lining technology was thick electrostatically applied fluoropolymer coatings. Though slightly less expensive and much more efficient than sheet linings the relative cost is still significantly higher than traditional rubber or elastomeric linings. The goal was to find a substitute thermoplastic resin, probably non-fluorinated because of raw material costs, to be a viable replacement for traditional rubber and synthetic rubber linings. After some testing and evaluation over a period of years, a replacement coating for elastomeric linings has been found. It is a copolymer of polyethylene and polypropylene and offers the industry a number of advantages. First of all, it is competitive in price to an elastomeric lining. Extraction studies were done and confirmed the relative cleanliness of this type of lining. This new coating makes rubber and elastomeric linings obsolete by offering greater service life, lower extractables, smoother surface and greater adhesion to the metal substrate.