Initial results of German efficiency research show PET promise
The government-sponsored research is being undertaken at the Research Centre of Karlsruhe, in association with industry partners such as filling and packaging giant KHS Corpoplast and AdPhos Innovative Technologies.
The study is being conducted at one of Okertaler Mineralbrunnen’s mineral water bottling plants in Germany, using KHS Corpoplast’s InnoPET Blomax Series III stretch blow moulder.
The project is monitoring the three specific consumption criteria involved in the PET bottle production process: raw PET usage, electricity and compressed air.
Material reduction
Denis Uluturk from KHS Corpoplast, an engineer involved in the study, said: “As a rule, 70 per cent of the cost for a PET bottle is attributable to the material used. Preform manufacture and actual production of the bottle account for a further 15 per cent of costs respectively.”
Initial published results from tests at the facility show that faster stretching of PET bottles leads to less material wastage and savings of around three per cent, meaning that PET weight for the 1.5l bottles produced at Okertaler Mineralbrunnen could be reduced from 31g to 30g.
According to Uluturk , even a one gram reduction in PET material usage would save 100,000kg per annum, assuming that the Okertaler factory produced 100m PET bottles a year. Factor in a market price of €1.2 per kg for PET, and €120,000 a year would be saved.
Electricity savings
Uluturk added that other tests at the facility showed that energy savings of up to 20 per cent were possible during the perform preheating process for the given 1.5l bottles, with the electricity required dropping from 0.15kw hours per kg to 0.12kw.
Usage of compressed air, the remaining resource input, could also be reduced by around 31 per cent for the given bottle size, with a further five per cent saving possible due to a redesigned shape for the bottle. Given these savings, the engineer said that electricity costs could be cut by €26,000 a year, presuming a rate of €0.10kw an hour.
With full results of the project pending in 2011, the research group plans to investigate further efficiencies with the given criteria, as well as conduct research into new heating technologies.
Uluturk said the implications for resource savings as a result of the project were massive, given that 25bn PET bottles are made in Germany alone, and 500bn worldwide each year.
“The enourmous number of PET bottles that pass through the hands of consumers every year shows just how important this project is,” he said.
“The data collected…could form the basis for optimised PET bottle systems at any number of similar companies, and used to generally classify stretch blow moulders that are particularly economic in terms of energy consumption.”
