PETpla.net Insider 06 / 2015

BOTTLE MAKING 24 PET planet insider Vol. 16 No. 06/15 www.petpla.net The 1Blow PET reheat stretch blow moulding machine design combines rotary and linear functions for process flexibility and high production. Linear and rotary functions on new PET bottle machine The 1Blow PET blow moulding machine 2L shown at the NPE 2015 The two common types of PET reheat stretch blow moulding machines - rotary and linear - are cost- and/or performance-prohibitive at production rates of about 4.000 to 8.000bph, according to 1Blow, of Boissy-l’Aillerie, France. It offers a range of compact, all-electric stretch blow moulding machines that use both linear and rotary functions to produce PET bottles ranging in size from 200ml to 20l (5.3 US gallons), and with neck finishes from 20mm to 70mm. Production rates extend from 500 to 8000bph. It can use blow moulds from manufacturers such as KHS Corpoplast, Krones AG, Sidel and Sipa SpA. The rotary blow mould- ing units are offered with six technol- ogy kits, to expand bottle design and functional possibilities. The rotary wheel design’s effi- ciency claims are based on the con- tinuous preform-to-bottle operation. The primary mechanical component is the rotary union or blow wheel, which supports and indexes the blow moulds around its circumference. 1Blow says that it is a highly complex, high-pre- cision component that houses critical utilities such as low-pressure air, high- pressure air, cooling water, electri- When the preform exits the oven it is transferred to a proprietary gripper and pitch-changer. Inside the oven the preforms rotate on spindles and have a pitch (centre to centre) spacing of 60mm; in the mould the pitch dis- tance is typically 120mm to 160mm, depending on machine brand. The pincers on 1Blow’s grippers can open up 180 degrees, which allows them to completely clear the preform’s neck finish. They traverse a servo-driven linear system to transfer the preform from the pitch-change unit to the mould. 1Blow has offered one-cavity and two-cavity units for several years and added a four-cavity model in 2013. A six-cavity standard unit and a model for production of wide-mouth bottles are in development. Other standard features include a high-pressure air- recovery system, Internet-ready con- nectivity, an on-board technical and maintenance manual, and an internal voltage modulation/regulation system that eliminates the need for an electri- cal transformer. www.1blow.com cal controls, recovery air and hot oil. It becomes less efficient and more expensive at lower production levels and has to rotate without leaking. The potential inefficiencies of linear-type reheat stretch blow units lie in their operating motion, which includes a non-productive return stroke. 1Blow’s in-line rotary machine uses 11 key motions to move the process from PET preform to finished bottle; 16/17 production steps are required in competing SBM units. Nine of the 11 functions use rotary devices; the final two steps of the process, preform into the mould and blown bottle out of the mould, are linear. The 1Blow design does not include a rotary union so the moulds do not move through the machine; they are stationed at the clamping/ blowing point. PET preforms enter the system by elevating conveyor and are moved to the preform orien- tation device and static-rail preform feeder. A star-shaped in-feed wheel transfers the preform to a carousel- style rotary reheat oven; its three banks of adjustable infrared (IR) heating lamps are claimed to provide capacity 50% greater than competing machines.