Nestlé Naturnes included a line of shelf-stable meals for babies and toddlers from 1998 – 2009, when it was discontinued due to the constraints caused by its packaging technology at the time. The company saw the potential of a range of microwave-ready meals for littlies, but packaging it was a stumbling block. Nestle was wrestling with two packaging options, glass jars vs. plastic pots, and in November 2009, it published a lifecycle assessment of the two, in which plastic was demonstrated to have three advantages – in production and end of life of packaging, in its reduced packaging weight leading to reduced transport impacts and in enabling the replacement of the retorting process with aseptic form-fill-seal.
Read the report in full here: Nestle Naturnes packaging report
According to Nestle, plastic pots deliver a 25% reduction in C02 emissions and energy consumption in production and transportation.
The company saw the potential of a range of microwave-ready meals for littlies, but the packaging technology of the day was a stumbling block. Nestlé engineers were given the task of working out a better way to automate the way the product was packaged. Eventually advancements in sensors, vision, and robotics systems made that possible.
Eventually, Nestle was able to introduce Naturnes microwave-ready meals in 250g (approximately, depending on variety) plastic pots made of four parts - a plate, flexible lidding material, and a footed overcap with an in-mould label. There are about 20 meals in the range, some for babies, some for toddlers.
This is how Nestle views the packaging: “The pack features light and stackable plastic bowls with re-closable lids for freshness. The design reflects consumer convenience and safety. Parents can hold the plastic bowl in their hand when feeding their baby; it has a solid base so it does not tip when children start to feed themselves. It can be heated easily in the microwave oven or in a bain-marie.”
And these are the highlights of the packaging capabilities that made Naturnes microwave-ready meals viable:
Packaging for the NatureNes line begins on the floor above the filling and retorting equipment where two custom-built systems from Del feed the plastic plates and overcaps to the floor below. The plates then ride a conveyor belt through three filling stations where cubed meat/poultry, vegetable mix, and sauce are fed onto the plates. At the third of these stations, the plates are heat sealed before they are picked up by another robotic system that begins the process of loading the units into trays and then into the retort crates, each of which holds 425 plates.
The retort crates move automatically onto a shuttle that moves to a large bank of retorts. An hour or so later, the shuttle removes the retort baskets from the cooking vessels and feeds them to secondary packaging, which is anchored by two more robots. Here, they receive 100% vision inspection, overcap application, and case packing on a pair of wraparound case packers.
On average, the plant, which is located in Werk Wieding, Germany, can produce 180 units of product per minute with just eight operators. Each element of this system wascarefully engineered and built or customised specifically for the packaging process and the system relies heavily on automation. New generation robotics play an important role.
The improved vision system, ThermoSecure L100 by Luceo, is a key component of the new capability. It examines the sealing area on all units of NatureNes. Should any product contamination be detected, the unit is rejected. The system also detects any unit that might have food product or sauce on the top of the lidding, which consumers may find unappealing or a sign of poor quality.
Nestlé and Luceo had to develop a graphic for the product that would be better suited for an automated process. Originally, the graphic was printed with a very dark blue ink, which was difficult for the camera system to see through to properly inspect the product. So a lighter blue was chosen, allowing the system to view through the ink and ensure product quality.
The small flap of material in the flexible film lidding that makes it easier for the consumer to peel the package open is still being perfected. Occasionally, it gets bent back during the retort process, so that when it is inspected the camera system will see something out of the norm and cause that package to be rejected even though there is no product contamination and the hermetic seal is fine. Although adjustments in software algorithms improved the problem, it is not yet removed entirely.
The intermittent-motion, volumetric pocket filler is a Waldner Dosomat 20. Its transport belt takes plates eight across through three filling stations. The third station is where roll-fed lidding material is heat-sealed in place. The lidding, supplied by Mondi, is a multi-layer co-extrusion of polyester/tie/OPA/tie/white peelable PP. The composition of the inner layer of white polypropylene is crucial because of the need to ensure a hermetic seal in the retort that still allowed the container to be easily opened in the home.
Kuka robots control the process of stacking and the lidded plates into pocketed metal trays so that they can advance to a Kruse + Sohn shuttle that runs on a railroad track embedded in the floor. It transports the retort crates automatically to a row of retorts.
The retorts and the shuttle system were already in place when the new plastic-plate-filling line was installed. These were used formerly for producing glass jars of baby food. (Glass-packaged product is still in production elsewhere at the Werk Weiding plant.) The engineers removed one glass line to put in the new plastic plate line and kept the shuttle system and retorts where they had been. A second shuttle was added to keep pace with the new plastic plate line.
The single-filed plates pass through a drier that blows off moisture to prepare them for overcapping and secondary packaging. They pass through the Luceo ThermoSecure L100 vision inspection system first.
The overcapped plates are fed to two downstream Meypack wraparound case packers where special tooling on the case packers collates the plates in groups of six and stands each one up on the footed portion that is part of the plastic overcap. This produces a retail-ready look. Batches of plates can range from 15,000 to 50,000.
