Lubrizol (Cleveland, Ohio; www.lubrizol.com) recently began producing chlorinated polyvinyl chloride (CPVC) resin in commercial reactors equipped with light-emitting diodes (LEDs) as the light source, instead of the conventional mercury lamps. The company’s LED reactor technology enhances the thermal stability of the product resin, allowing users of the resin the ability to run extrusion processes longer and to undertake more complex molds. The LEDs also reduce process energy costs.
In the manufacture of CPVC, light is used to generate reactive chlorine radicals, which add chlorine atoms to polyvinyl chloride (PVC) polymers. “Although mercury lamps have worked well in the past, they generate electromagnetic radiation across a range of wavelengths, including infrared, visible and ultraviolet, which can disrupt other bonds in the polymer,” explains Peter Kilburn, process improvement manager with Lubrizol. “The LED light allows us to be very selective with the wavelengths of light that are applied to the PVC polymers, and that minimizes the faults in the CPVC resin product and improves its thermal stability.”
Much of the CPVC resin Lubrizol produces ends up in the piping market. More thermally stable resins allow piping manufacturers to extend the run times of their extruding equipment and increase throughputs. In addition, maximizing thermal stability ensures meeting their customers’ high-performance application demands across their markets, says Griffin Rial, Vice President TempRite® CPVC.
The new full-scale LED chlorination reactor, which is installed at Lubrizol’s flagship facility in Louisville, Ky., adopts similar geometry to the conventional CPVC reactors, and the Lubrizol team engineered the LEDs to fit into the same space as that occupied by the original lamps in conventional reactors.
Lubrizol engineers are currently working on process optimization in the Louisville unit by establishing the correct conditions for pressures, temperatures and flowrates. The company is planning to expand the LED chlorination innovation to all its global manufacturing sites in the future.