We originally reported last July on Sidel’s launch of the base for still drinks – StarLite used two patented innovations therein that reduces the amount of PET used, for a thinner bottle with (Sidel claims) the optimum strength-to-weight ratio.
Using the same principles, Sidel researched a carbonated option – where PET bottles are clearly under greater pressure – analysing different base designs and running computer simulations prior to real world testing.
Patent-protected technology
StarLite for CSDs is protected by four patents that cover the slopes, ridges and truncations of the bottle base, and Sidel claims it is easier to blow than previous bases for fizzy soft drinks.
Sidel says several of its customers have trialled the base with carbonated soft drinks (CSDs) using test protocols drawn up by the International Society of Beverage Technologists (ISBT).
The company claims that the new base lasts 30% longer than standard bases for 500ml bottles, 50% longer for 1.5 liter bottles and 60% longer for 2 liter bottles.
Base weights, Sidel asserts, can be cut by up to 20% for 500ml bottle (down to 4g), 19% for 1.5 liter bottles (9g to 7.3g) and 17% for 2-liter bottles (12g to 10g).
Upon this basis, Sidel estimates line savings of up to €331,000/year for 500ml lines, €563,000/year for 1.5 liter lines and €662,000/year for 2-liter lines due to lower material usage alone
Less manufacturing pressure
These statistics are based on Sidel’s SBO 20 Universal 2 blow molder running for 6,000 hours/year at 2,000 bottle/hour output and PET costs of €1,600/tonne (2000kg: Sidel uses the metric system).
Since the new CSD bases can be blown using 20 bars of air pressure compared with 28-30 bars (on average) for 2-liter bottles, for instance, Sidel insists that further savings of €78,700 are possible using this bottle size alone, given lower electricity usage.
Together with material savings this means possible savings, on a 2-liter PET line, of $1m+, according to Sidel’s calculations; the French company says that high line speeds of up to 2,800 bottles per mold, per hour (for 500ml bottles) are also possible using its Matrix system, rolled out from 2013.
The base completed the ISBT’s 24-hour creeping test at 45C, Sidel said, compared with 38C under standard testing procedures – showing its good resistance and reduced likelihood of bursting during production or deforming during transit, as well as its allowance for more stable pallets.