INFLUENCE OF THE PET MATERIAL GRADE ON THE ENERGY EFFICIENCY OF THE REHEAT PHASE IN THE TWO-STAGE STRETCH BLOW MOULDING PROCESS

摘要

From a cost perspective about 7% of the total production costs of a stretch blow moulded bottle are spent for energy in order to reheat and blow the preform to the later bottle. Due to this significant share and due to the increasing energy costs over recent years, the industry is interested in increasing the energy efficiency of the stretch blow moulding process. At the Institute of Plastics Processing (IKV), the influence of the PET material grade on the energy efficiency of the reheat processes was investigated. Six materials were tested by spectroscopic, caloric and temperature measurements. In experimental trials on a laboratory stretch blow moulding machine, differences in energy consumption of 26% and differences in heating time of 33% were verified. Furthermore, an approach was adopted to account for varying absorption properties of the examined materials in a reheat simulation. It was shown that the reheat simulation is qualitatively able to characterise the specific reheat characteristics of different PET grades.