A synergy of technical sophistication and efficiency

 The stretch blow moulding machines from the Contiform series of Krones AG is one classic example of how a good combination of technical sophistication and long years of experience in mechanical engineering can create a superior package. In order to meet clients' specific requirements, the machines are available in a choice of different sizes and model variants. This enables Krones to cover the entire spectrum of bottles involved, from 0.1 all the way up to 5.0 litres. Depending on the container size concerned, the Contiform can reach a maximum output of 72,000 containers an hour.
The wide choice of Contiform models is aimed at providing the right solution to each and every requirement: standard or heat-set, stand-alone or monobloc layout, medium or high speed range, small, medium, normal or large cavities .
The Contiform S operates according to the two-stage process in which PET preforms are blown to form bottles. To do so, the prefabricated preforms are first carried through a modular linear oven which has been heated up to its optimum processing temperature. They are then transferred to the cam-controlled blowing wheel where compressed air and a particularly economic application of energy are used to blow mould them into bottles. The machine is ideal for the production of PET containers with a volume of 0.1 to 5 litres. Specific variants in this series include: Contiform S for containers up to 3 litres; Contiform S, K series for small containers up to 0.7 litre; Contiform S, M series for medium-sized containers up to 2 litres; Contiform S, G series for large containers up to 5 litres; and Contiform H for hot-filled containers up to 2 litres.
The series has a modular linear oven which can be configured in accordance with the speed and process. Depending on the requirements, units are available with a chain pitch of 40 or 50 mm. The preforms are heated whilst suspended, their neck finish facing upwards. To cool, the preform neck finish is cooled by a guided, adjustable current of cold air. The machine also features swing-out oven benches with quick-locking device for the heaters. Very light and compact heaters with integrated electrical plug-in connection are also integrated. The closed heating tunnel ensures long life along with maintenance-free ceramic reflectors.

Hot and economical
For still fruit and vegetable juices, coffee, tea and soya beverages to remain preserved for a long time without the use of preservatives and other additives, these must be hot filled.The temperature of the product is generally between 78 and 93 °C. To allow them to withstand such high temperatures, hot-filled PET containers must meet special requirements. They are produced in this way so that: no permanent deformations are created when the bottles are filled; the containers can absorb the vacuum pressure ; the volume does not shrink below 2%; and the screw thread is not deformed- meaning that the cap can seal the bottle tightly.

The PET bottle must withstand several stresses during hot filling and these include temperature rise during filling, pressure increase and bottle shrinking after closing by heating the air in the head space, and vacuum creation during cooling of the product. These requisites are met by Contiform H.
PET containers later used for hot filling are manufactured in the so-called heat-set procedure. Infrared emitters first heat the preforms to the required processing temperature which lies just below the PET crystallisation point. Subsequently, the preform is stretched in a heated blow mould and is then blow-moulded to form a bottleGirls Air Jordan 1