Willowton switches to in-house PET bottle production for sunflower oil with Sidel blowers

After working for many years with local converters, Willowton in South Africa has increased its production volumes and revolutionised its sunflower oil brand, Sunfoil, with Sidel’s expertise in polyethylene terephthalate (PET) blowing and packaging design.

Founded in 1970, Willowton is a South African oil seed processor and edible oil packer. It is also a manufacturer of edible oil, and owns the sunflower oil brand, Sunfoil. With its in-house oil refinery that has been in operation for over four decades, Willowton also produces edible oil for retail brands.

To increase its yearly production volumes and differentiate its Sunfoil brand from traditional edible oil brands with generic container shapes, Willowton decided to partner with Sidel to produce its polyethylene terephthalate (PET) containers in-house. To achieve this, the company acquired two Sidel EvoBLOW blowers, and relied on Sidel’s packaging design skills and experience to help it develop customised family bottle shapes.

One of the advantages these new standalone blowers offer is a more independent bottle production set-up. The equipment also enables efficient production planning and reduces warehouse space. The SBO 16 EvoBLOW produces a two-litre format while the SBO 10 EvoBLOW produces all bottle formats up to one-litre. As the latter manages various bottle formats, Willowton also chose to install a mould Bottle Switch system to conduct bottle changeovers.

Faisal Modi, operations manager at Willowton, explained: “This easy way to adapt our oil production to the fast-moving market demands contribute to a great production flexibility.” The system is based on repeatable, tool-free operations that allow the operator to spend only 30 seconds per cavity, thereby increasing production flexibility, equipment availability and production uptime. Both machines can operate at an efficiency level of 99.5% due to the production buffer created by the storage silos located on the lines.

“With those two blowers, we already increased our yearly production volume by 50%, and we are ready to handle any future additional demand as well,” Modi added.

To meet consumer expectations on hygiene, the two Sidel blowers have been equipped with different options to ensure production integrity. These include preform dedusting, air filtration, air recovery, and automatic centralized greasing.

Starting from a series of modern designs that were developed using bottle drafts and digital mock-ups, technical designs and prototypes with 3D printed models, the new cylindrical Sunfoil silhouette with a drop logo engraved on the bottle shoulders was created. This bottle features a belt-inspired design, and reduced diameter to make it easier to handle.

The new shape has been applied to different family bottle sizes, including 375ml, 500ml, 750ml and two-litre rectangular bottle. The latter was most challenging because blowing a rectangular bottle without any specific preferential heating blowing process affects the structural rigidity of the container. Sidel therefore conducted various packaging evaluation and qualification tests on the two-litre bottle, including Finite Element Analysis (FEA) and feasibility trials to improve its strength and performance across supply chain simulations. The bottles are equipped with push fitting or screw closures.

To make the most of the blowers’ operation, Sidel also organised training courses for the Willowton operators before and after the equipment validation process. They were performed by Sidel local technical team on-site, and empowered the Willowton team enhancing their skills while reinforcing trust between Sidel and Willowton.