German filling and packaging systems manufacturer KHS has developed a preferential heating system for bottlers dealing with a range of unusual bottle shapes.
Special bottle shapes make high demands of many stretch blow moulders during production, but the KHS system can product the right result, even with extremely oval bottles, as part of the InnoPET Blomax Series IV.
The stretch blow moulders in this series enable the energy-efficient manufacture of PET bottles through preferential heating fillers.
Compared to previous machines, the new ones use much less energy and a simpler design, especially when processing items such as cleaning agents, laundry detergents or personal care products which are often filled into oval PET bottles.
"Without preferential heating the preform is heated evenly in the stretch blow moulder," Marco Böhnke, product manager at KHS Corpoplast, says.
"This means the areas of the bottle which come into contact with the blow mould first cool down before the others."
As a result, the PVC hardens at these points so that the material is distributed unevenly in the ensuing bottle.
Preferential heating is made possible by a special heater section at the end of the heating segment.
Here, the system first rotates the PET preforms through the heater to obtain a basic heating profile.
In the downstream PH section rotation is stopped, giving the preform its selective heating profile.
The new heater box specially developed for this application plays a big role here, transferring the required heating energy to the preform through two opposite heater levels.
"We're generally improving quality, especially the material distribution and stability of the bottle," says Böhnke.
"Also, thanks to this intelligent technology we can realise material savings of up to several grams per bottle."
