Chinaplas: Titanium-based additive reduces PET reheat blow energy by 38%

An independent comparative study carried out by stretch blowmolding machine vendor Sidel (Le Havre, France) has shown that Joule RHB titanium nitride-based PET reheat additive from ColorMatrix (Knowsley, UK), offers the largest carbon footprint reduction in PET preform processing, while maintaining superior performance and aesthetic qualities.

Joule RHB is compounded into PET resin by the supplier during the polymerization process. ColorMatrix also offers a similar product known as SmartHeat, which can be added by the processor to the PET melt at the preform injection stage.

The study compared resin containing 5 ppm Joule RHB-2, an inert blue-shaded inorganic particulate, with a typical 5-ppm carbon black commercial reheat resin and a commercial non-reheat resin. Joule RHB-2 outperformed the other materials in terms of near infrared absorption, L* luminance (an indication of container clarity), reheat efficiency and energy use. These reductions in energy use, energy cost and CO₂ emissions coupled with superb recycling credentials reportedly make Joule RHB-2 the natural choice for PET processors wishing to improve the sustainability and environmental credentials of their products.

Sidel tested the three materials in the form of 18.8g, 500-ml carbonated soft drink (CSD) bottles and compared various qualitative characteristics. Examining preform temperatures at constant power levels showed Joule RHB-2 was significantly more effective at increasing infrared absorption than the current commercial alternative: its temperature was 125°C, compared to 114°C and 96°C in the untreated resin. At 5.8°C reheat per ppm additive, Joule RHB-2 was 60% more efficient in terms of reheat than the commercial alternative (3.6°C per ppm).

Using data from the Sidel study, ColorMatrix determined the energy required to blow one metric ton of PET. With no reheat additive, this was 221 kWh. 19% energy savings were enabled with the commercial carbon black reheat resin (179 kWh) but a reduction of 38% (to just 138 kWh) was made possible by Joule RHB.

The energy reduction enabled by ColorMatrix's technology was then translated into financial savings and cuts in carbon footprint. Assuming a cost of €0.07/kWh (9¢), Joule RHB-2 offered almost double the cost savings and twice the CO₂ reduction of the alternative reheat agent. At the same time, inspection of container clarity (L* luminance) showed these notable processing benefits were accompanied by good container clarity.

ColorMatrix has built on the results of the Sidel study and developed a simple but representative PET resin calculator, which is now available as an app via the Apple ITunes at this link. Processors just need to specify their annual PET tonnage and energy cost per kWh, and the calculator shows them what energy, CO₂ and financial savings they might expect to achieve using ColorMatrix technologies."

Joule RHB is available as a 10% liquid dispersion in ethylene glycol and is suitable for use in all PET process technologies. FDA and EU food contact approved for use in PET bottle resins, it is used at 2-10 ppm depending on container type, size and thickness.

ColorMatrix also notes that Joule RHB and SmartHeat continue to function perfectly in terms of thermal properties and clarity over multiple resin recycling cycles.-[email protected]