UK-based GR8 Engineering has developed EcoForm, a machine for producing rigid plastic food packaging within the filling hall.
According to the Chichester-based company, EcoForm “makes shapes no other process can”, in a hybrid stretch blow moulding process using injection moulded preforms, said to be very similar to two-stage SBM for PET bottles.
The Ecoform process starts with a mainly flat preform moulded by GR8’s own patented VDM injection compression moulding technology, to produce preforms that have very low stress, fast cycle times, and can be profiled to give the best material distribution.
The preforms are reheated in the EcoForm machine using a patented very low energy conductive heating stage, then the preform is transferred to a hybrid stretch blow moulding station, which also in part uses thermoforming.
“GR8 have found that this combination achieves the best material distribution together with very high biaxial orientation, giving the products greater strength and rigidity than can ever be achieved by thermoforming,” the company says.
Into the cauldron
Produced using a pair of blow cavities and manufactured from aPET with a stretch ratio of 10:1, the first container produced using GR8’s prototype system is known as a ‘cauldron’ – hitherto said to be an extremely challenging shape to replicate in plastic.
“During rigorous product testing the container continually survived a 5-metre drop onto concrete when filled with frozen water, without any splitting, cracking or splintering,” GR8 Engineering says.
Other testing has seen the cauldron containers filled with ice cream, frozen down to -25°C, and dropped 2 metres onto concrete, with equally successful results.
EcoForm machines can also be configured using a one-piece cavity, or a cavity comprising four segments, allowing a product to be embossed all the way around.
The systems are designed to be situated within the food filling hall, meaning that nesting of empty containers is “no longer an issue”.
“This gives designers virtually a free rein to come up with new and innovative packaging designs that have up until now been impossible to bring to reality,” the company says.
Compact
Machine outputs will be from 10 million units per annum for a single lane system, up to 55 million for a four-lane machine.
The machine itself will be compact in comparison to existing thermoforming systems, with a single lane system being around 2.5m x1.5m x 2m high, while a four-lane system will only be a 2.5m cube.
GR8 Engineering anticipates the first commercial EcoForm system will be in the market in 2015.
