The customer is one of a growing number of companies taking a shine to SIPA’s linear SFL 2/2 twin-cavity system. That’s because not only is it very good at stretch-blowing big PET bottles, but also because it can be quickly and easily converted from making one size to another, minimizing valuable downtime. This trend is particularly marked in South America, where large PET bottles are particularly popular for drinking water.
In this case, the bottling company, located in Chile, wanted to make PET bottles sized 6.5 liters and 5 gallons (almost 19 liters). The 6.5-L bottles are single-use types, while the 5-gal bottles are returnable. It had been using polycarbonate bottles in these sizes – buying in the bigger ones and blowing the smaller ones on an old machine in-house -- but it decided to switch to PET, and bring all production in-house.
The new set-up allows the company to run the SFL 2/2 on-line and off-line, so that it can match the speed of its filling line with the speed of bottles coming in. The 5-gall bottles are produced off-line, enabling the company to build up a stock, integrating bottles blown in-house with others coming back from the market after use, before it starts to fill them on the filling line. Then, when it wants to produce and fill 6.5-L bottles, it switches to in-line blowing and filling.
The SIPA system is now producing up to 500 5-gal bottles per hour, each weighing 680g, and with a 55-mm neck. When producing the 6.5-L bottles, weighing 85g and with 48-mm necks, output is close to 1500 bottles per hour.
Format changes are fast on the SFL 2/2, partly because the unit has a twin system for unscrambling and loading preforms, according to their size: one that orients the preforms using a roller (for standard preforms), and one that uses a robotic manipulator (for special preforms with body diameters larger than the support ring diameter) . Only a few components actually need to be changed: star wheel, plates, preform guides, and that’s it. Two operators working together can have the system back up and running inside 50 minutes.
For customers wanting to blow even bigger PET bottles, SIPA also offers the SFL 1 XL. This can produce containers anywhere from 15 to 30 liters in size, and answers calls from the market for low unit costs. The SFL 1 XL is ideal for production of returnable containers at a rate of around 250-300 units per hour, or as many as 700 stackable/one-way containers in the same period.
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(Photo credit: SIPA)
