PETpla.net Insider 03 / 2020

BOTTLING / FILLING PET planet Insider Vol. 21 No. 03/20 www.petpla.net 33 TES STM Group’s Blueline machinery range From stretch blow moulding to hot filling TES STM’s Blueline range of PET preform to bottle linear stretch blow moulding machines includes machines with capacities of 3,000-18,000 bph, depending on the number of cavities. Output is up to 2,250 500ml bottles/hour/cavity. The machines can be equipped to produce oval PET bottles, using a preferential heating solution that allows optimisation of wall thickness; there are also options geared to production of very low volume (e.g., 10ml) bottles, and bottles that can be hot-filled. Blueline series machines are fully electric: all major movements are carried out by electric drives, most of which are servomotors. The control systems enable operators to conduct full, online diagnostics. Energy-efficient heating ovens are equipped with specially-designed ceramic panels that reflect infrared radiation and help to reduce con- sumption of electricity needed during preform heating, to less than two Watt-hours per 500ml bottle. Blueline HF series machines, which are designed to manufacture Hot Fill (HF) bottles, are equipped with four, six or eight cavities and have output capacity of up to 12,000 bph, depending on preform weight, material and filing tempera- ture. The HF production process is based on the application of a hot blow mould, which allows a higher degree of crystallisation and, con- sequently, have increased thermal resistance. After the blow moulding process, the bottle is cooled down by compressed air, delivered through holes located in the stretch rods. After leaving the blowing mould, bot- tles are further air-cooled, in order to stabilise contraction. The machines’ electric heaters are located in the blowing block and in the bottom part of the moulds, which are equipped with sensors that constantly monitor temperatures and thus provide full control over the process. These fea- tures help to ensure consistent high quality and dimensional repeatability of bottle production. Preform necks are protected against deformation by water cooling. The blowing moulds are water-cooled at the point of contact between the neck and mould. The cooled part of the blow mould is iso- lated from the heated part in order to minimise loss of energy. Reducing production costs The Blueline series stretch blow moulding machines incorporate a number of features aimed at reduc- ing production costs, including a system that recovers compressed air from the blowing process, in two ways. The first diverts a part of com- pressed air from the blowing process to the stretch blow moulding machine control system. This means there is no need for a separate supply of compressed air for the pneumatic control system. A second solution allows recovery of compressed air used in the blowing process, in order to supply other devices down the line, such as the filling machine, labeller, etc. The company says that this solution is currently unique to Blueline blow moulding machines. These two features help to reduce compressed air consumption by as much as 50%. TES STM has patented a method of using hot air from the heating ovens to pre-heat preforms. The heating oven, which is equipped with NIR lamps, is cooled with air drawn from outside the machine, which is circu- lated by a fan. The air that has been heated during the cooling process is then circulated to provide initial heat- ing of preforms. This solution helps to reduce electricity consumption for preform heating by 4-5%, depending on weight and shape. The Multiflex option, available on the HF series, is designed to speed up changeovers. Retooling for produc- tion of bottles with different preform necks is cut to around 30 minutes, which means that bottles with various threads can be made on the same blow moulding machine. Blueline series stretch blow mould- ing machines are designed as a solu- tion for small and medium producers. www.tes.com.pl The machines’ electric heaters are located in the blowing block and in the bottom part of the moulds. FILLING Stretch blow moulding machine from the Blueline series of TES STM