KHS Corpoplast’s new stretch blow molding process recycles up to 40% of compressed air
KHS Corpoplast has introduced a new stretch blow molding process for the manufacture of PET bottles. The new Airback Plus is said to recycle up to 40% of the compressed air used during the process in the blowing wheel instead of the previous 10%. Airback Plus is used in conjunction with the Airback I process, says the German machinery supplier. With Airback I, the quantity of compressed air which is present in a newly produced bottle and which is required for blow molding the next bottle is fed into a ring line located at the center of the blowing wheel. From here it passes directly to the preform, enabling savings in compressed air of around 10% to be made.
The pre-blowing phase (PI phase) is followed by the blow molding of the bottles at high pressure (PII phase). In the Airback Plus process more compressed air which can still be used is extracted from the manufactured bottle. This is supplied to the pre-blown container at a higher pressure (interim pressure stage), achieving an additional saving in compressed air of up to 30%.
Another advantage of using Airback Plus, according to KHS Corpoplast, is that less energy and a lower volume of high-pressure air are required for the stretch blow molding process than was previously the case. The compressor can therefore be smaller, resulting in reduced investment costs and ongoing cost savings through fewer spare parts and reduced maintenance costs and effort being required. The system can also be retrofitted into existing InnoPET Blomax Series IV and InnoPET Blomax Series III stretch blow molders.