Before the consumer can enjoy a glass of any soft drink, each sip has to complete an extensive journey down a production line that has been tailored to the product and the pack in which it is contained. In other words, process, package and filling method are directly related to each other.
It would be a mistake to assume that the pack alone is responsible for presenting a soft drink to the consumer that is fresh and appetising. The right processing and filling equipment is of equal importance. Get it wrong and one could be a spectator at the death of a famous brand.
Generally speaking, glass, plastics, aluminium, steel and carton packs are used to contain soft drinks. While the attributes of each material are well documented, it is worth noting that plastics decreases transport costs because it is almost unbreakable and light. The material also offers considerable freedom where shape and dimensions are concerned.
The filling system used – ranging from standard to aseptic systems – will depend on the processes used, the type of pack and the required shelf life. Hygienic systems fill containers in an atmosphere with HEPA-filtered air. Cleaning in place or sterilisation in place systems are also possible.
Ultra clean systems are specially adapted to minimise the size of the filling section. Such systems have special filler nozzles that increase filling speed and accuracy and an integrated CIP/SIP system. Aseptic fillers, of course, fill the product under in decontaminated containers.
For the sake of simplicity I will examine a series of production lines suited to freshly squeezed and pasteurised juice. All have been designed by the Dutch company, Stork. Freshly squeezed juice undergoes no treatment whatsoever. Therefore, it has a very limited shelf life so the product has to be stored under well controlled, refrigerated conditions.
Such a line is suitable for processing HDPE, PP, PET and glass bottles as well as cups with a capacity of 100ml-3litres. The production line transports the containers to the filler, where they are filled precisely with the pre-set quantity of juice so ‘give-away’ is minimal. The containers then arrive at the dosing station. Here, too, there are numerous possibilities such as heat or induction sealing, twist-off, and snap-on, screw cap closures. The bottles are subsequently labelled with self-adhesive labels or sleeves.
Needless to say, there are a number of inspection systems incorporated in the line that check whether the packaging has been correctly closed and whether the label is present.
At the next station, the bottles or cups are placed in the secondary package such as cases, trays or shrink foil. Lastly, the secondary package is collated and palletised or the loose bottles are loaded in roll-on, roll-off containers.
The line for pasteurised juices is comparable to the fresh juice line but the juice undergoes a heat treatment that gives the product an extended shelf life.
Depending upon the packaging and the filling method, the shelf life can vary from a few days to several weeks.
The pressurised juice has to flow through a tubular flow steriliser at a high speed before it is pasteurised at a temperature in excess of 70° C. The juice is then rapidly cooled to the filling temperature which is usually a few degrees Celsius.
This treatment ensures that a large proportion of the harmful organisms in the juice is eliminated without affecting the taste to any appreciable extent.
Such a line is suitable for processing glass and plastics bottles as well as cups and carton containers. Where cartons are concerned a carton-filling system is integrated in place of a rotary filler. The cartons can subsequently be packed in secondary packages or loaded on trolleys.
On a hot-fill line the juice is first heated and the containers are then filled with the juice without pre-cooling. The heat of the juice eliminates any harmful organisms that are either in the package or introduced during the filling process.
Once the juice has been heated to the pasteurisation temperature, it flows to the filling machine without being cooled, where it is filled in glass, HDPE, PP or PET bottles, cups or pouches.
Not all plastics can withstand the high filling temperature that causes the bottle material to become soft and may result in deformation. In this case, different packaging material will have to be used such as heat-set PET bottles.
The line can be configured to handle different container volumes. After filling, the package is closed at the closure station with a seal, a screw cap or another type of closure.
A pasteurising tunnel may be incorporated in the line. In this tunnel, the filled containers are kept at the filling temperature for some time to eliminate harmful organisms. Once containers have completed their journey through the tunnel, a label or sleeve can be applied before they undergo secondary packaging and palletisation.
An aseptic line will only be chosen when very high requirements, relating to shelf life and quality, are set for a product. Products, in which preserv-atives are undesirable but must nevertheless have a long shelf life, can also be filled on this type of line. Cost savings tend to be generated by lower packaging and processing costs.
HDPE, PP, PET bottles or cups are filled, ranging in volume from 20ml-4litres. The bottles can be of the mono-layer type but also three-layer with a light barrier or six-layer with both oxygen and a light barrier.
When a user opts to fabricate the bottles in line, this has the guaranteed advantage that the bottles are internally sterile and arrive at the filler closed and filled with sterile air or nitrogen. The closed bottles make internal decontamination unneces-sary.
Bottles that are blow-moulded with nitrogen help to minimise product exposure to oxygen during and after filling. When the filler/packer opts for open bottles, however, these will have to be thoroughly decontam-inated and/or rinsed before they are filled. This is done with the aid of a decon-tamination station integ-rated in the filler.
An in-container processing line is generally used for processing juice products and low acid drinks that are packed in cans, glass or plastics. These are products with a long shelf life that can be stored unrefrigerated and whose taste deteriorates only slightly, if at all, as a result of slightly more protracted heating.
Such a concept is suitable for a variety of containers, including pouches, both as regards to volume and shape. In principle, the product is filled and supplied to the line in closed containers.
On the line the containers are heated to the required sterilisation temperature for the required length of time. After this, the containers are cooled to room temperature.
Labels can then be applied as well as the barcode and any other required marking. The containers are then packed in their secondary package in the form of cases, trays or shrink film.
Lastly, the secondary packages are transported to a palletising station where they are collated on pallets and, if required, stretch-wrapped for transit stability and to protect the load from dust or water.
An aseptic line can be equipped with a choice of two heat treatment systems. The first consists of one or more retorts, while the second comprises a continuous steriliser. Both are complemented by a supply system.
In retorts, the treatment takes place in batches. In the second instance, the products are passed through the steriliser in a continuous process. Both in the retorts and in the continuous steriliser, the process can be finely adjusted.
In both systems, use can be made of a flexible system consisting of stainless steel cassettes in which the cans, pouches and other types of pack are placed. The cassettes can be configured to accept every type of packaging with the aid of inserts.
The packaging is firmly secured in the cassettes so that they cannot be damaged during the process. The products remain in the cassette until they reach the secondary packaging station. The cassette makes the packer/filler’s production facilities flexible in capacity and the use of different packages.
Obviously, every manufacturer wants to market easily distinguishable products. His product or range of products should command such an eye appeal that they stand out among those of other makes. A branded bottle shape, in conjunction with a label or sleeve offering additional brand identity, would serve as an excellent vehicle to achieve this goal.
A co-extrusion blow-moulding machine offers the packer/filler just that opportunity to provide his product with his own brand identity.
A high quality product demands high-quality handling. Careful treat-ment and packaging will give the product a substantial added value. The product should be in a perfect condition when it gets into the consumer’s hands.
Careful internal transport and effective secondary [shrink-wrapping, tray, outer case] and tertiary [stacked pallet] packs are indispensable aids to ensure that the product keeps its value.
The correct selection of conveyor systems for the internal transport of products and secondary and tertiary packs is of paramount importance and the control of these systems may be integrated with that of other line components to attain maximum logistical efficiency.