Declining purchasing power encourages consumers and manufacturers to save on product packaging, especially in cases when branding and advertising do not have a sufficient impact on sales. As a result, the share of unpacked goods in Russia in various categories varies from 5 to 45%, and numerous stores, markets and even large hypermarkets sell meat products, fruit and vegetables as well as dry and granulated (grocery and confectionery) goods by weight rather actively, and consumers actively buy them as well. However, when it comes to liquid and viscous products, it is virtually impossible to deliver them to consumers without a package. Consumers’ suspicion of kvass or milk sold from barrels is not unfounded. Milk vending did not take root in Russia for reasons worthy of a separate discussion. Craft beer sales in specialized outlets are perhaps the only example of successful sales of draft beverages in the segment that are classified as retail trade rather than belong to HoReCa. And even though said category is characterized by rather high growth rates against the current crisis in the beer industry as a whole, on the scale of the whole market the trend is rather modest, satisfying demands of only a small share of the target audience. Given the above, almost all liquid and viscous goods produced by the domestic food industry today are sold to consumers in packaged form. Beyond doubt, packaged liquid foods are hygienic and convenient to consume, and therefore filling equipment for liquid foods is an integral part of any production line at companies manufacturing beverages (alcoholic and soft drinks, drinking water, juices and others); vegetable oils; sauces (soy sauce, mayonnaise, ketchup and others); liquid dairy goods (milk, kefir, yogurt and others); or confectionery syrups and toppings.
Filling equipment comes in direct contact with both packaging containers and the goods themselves. The process and results of packing largely depend on the features of a given product, and requirements for said equipment, materials for its manufacture, and maintenance (regular washing in particular) are always high.
The following factors are taken into account in selecting equipment for packing liquid and viscous products:
* the product’s individual properties;
* product mix width;
* container type and sealing method;
* technologies of product manufacture and their specifics;
* temperature of the product arriving at the packing line;
* product shelf life before packing and requirements for shelf life upon being packed;
* production scale;
* marketing strategies used by the company;
* the company’s requirements for hygiene in the packing zone.
Containers used for packing liquid and viscous foods can be produced from various materials, and these have their advantages and disadvantages. Liquid and viscous products are packed in either finished containers (packets, bottles, cans, cups and buckets) or in packaging formed from preforms in the process (e.g. doypack solutions; 3-side seal rectangular or triangular pouches from polyethylene or combined materials).
Each category of liquid products is characterized by its specific standards and preferences in terms of packaging, but there is one universal trend which can be observed across them all – growing demand for polymer (PET and HDPE) packaging when it is legal and appropriate given the product properties and consumption stereotypes.
The main varieties of packaging for viscous and liquid goods are as follows:
* PET and HDPE containers (bottles, cans and buckets);
* glass containers (cans and bottles);
* aluminum cans (for beer and other beverages);
* polyethylene or hybrid (paperboard plus polyethylene) 3-side seal pouches (for dairy goods);
* hybrid (polyethylene, foil and paperboard) containers such as Tetra Pak, Pure-Pak, Tetra Rex or Tetra Brik;
* Ecolean bags;
* doypack bag varieties (preforms with an inserted nozzle or those formed on the line);
* aluminum and laminate tubes.
Packaging costs are typically directly proportional to product value. The most expensive, premium type of packaging for liquid and viscous foods are bottles and cans made of glass. Bottles are the most popular type of glass package. Despite evident growth in the segment of canned food and jam production, the share of glass bottles in the total volume of glass containers is less than 15%. Aggregated demand for colored and clear glass containers depends on a number of parameters and can vary across different product categories. Demand for colored glass can be observed primarily in manufacturers of alcoholic beverages produced from natural raw materials – namely beer and wine, which are particularly susceptible to sunlight and contact with oxygen. Non-alcoholic drinks in the premium segment as well as liqueurs and spirits are mainly packed in transparent bottles in order to attract consumers with the product’s color and to demonstrate the crystal clear texture of the drink. Manufacturers of juices in the premium segment are prone to using glass containers as well, aiming to highlight the products’ naturalness and also having to adapt to specifics of technologies used and production limits. Companies producing juices for the mass market, on the contrary, opt for more efficient lines packing juices in containers such as Tetra Pak and Pure-Pak.
The bulk of aluminum packaging produced finds its application in the segment of beverages. The main product type packed in said containers is beer – however, manufacturers often use this type of packaging for other low-alcohol or non-alcoholic beverages from their range on the same line.
Combined packaging and packing technologies such as Tetra Pak, Tetra Rex, Tetra Brik and Pure-Pak are in demand in categories of liquid foods with a short shelf life. Tetra Pak and Ecolean equipment is strictly tied to container production. Pure-Pak technologies are more flexible and make it possible to choose an equipment supplier, but the shelf life of products in this packaging is usually shorter. The main type of container for drinking water and soft beverages are PET bottles with the volume between 0.33 and 2.5 liters.
Dairy products with the shelf life of 5–14 days are mainly packed in PET bottles and rarely in HDPE bottles.
Polyethylene and hybrid (polyethylene plus paperboard) 3-side seal pouches, including rectangular pyramid-shaped bags, are used exclusively in the dairy industry and are being gradually replaced by packaging types more convenient for consumers and manufacturers. The main disadvantage of these containers in the context of consumption is the lack of possibility to open and close them multiple times, which affects the shelf life and convenience of storage of the product opened, which does not fit well with consumers’ active lifestyle. In addition, packing in 3-side seal pouches is characterized by larger amounts of rejects compared with packing in PET containers and hybrid packages such as Tetra Pak or Pure-Pak. Rejects do not only occur in materials, but in products as well, and result in the need to stop and wash the equipment, which lowers performance. For this reason PET and HDPE bottles steal the spotlight as packaging solutions, as they have a number of advantages:
* Convenience and ease. The mass of a glass bottle is 200–300 grams, whereas the mass of a PET bottle of the same volume can be as low as 17 grams and less. A PET bottle can be comfortably held in the hand; it does not make the product and the product bag heavier and is demanded by the audience with an active lifestyle.
* Durability and resistance to external impact. PET bottles filled with fluids can withstand static vertical load of up to 140 kilograms and do not break even upon falling from the height of 1.5 meters. They are safe to be used by children. Moreover, the strength of extra light PET bottles containing non-carbonated beverages can be further enhanced and deformation prevented with the use of nitrogen dosing technologies (a drop of liquid nitrogen is added to the container before it is sealed, which results in the PET bottle feeling almost as firm as a glass bottle, although warmer).
* High tightness and the possibility of opening and closing multiple times, as well as reusability as a household item. An interesting example of reused PET container application would be using it for dry food storage.
* High thermoplasticity and shape diversity. This can be important in the context of promotion of packaged liquid goods in the market.
* High level of hygiene of new PET containers, which can be manufactured through extrusion molding from preforms at the enterprise right before packing.
* Low cost of containers, packing equipment and transportation of packaged products. This makes the product more affordable to the consumer, thus stimulating sales. A PET bottle 6 pack is optimal in terms of costs and spaciousness, which decreases the costs of PET container transportation approximately tenfold compared with glass packaging.
* Recycling potential. This field is not developed enough in our country yet and requires special consideration and promotion.
* Transparency allowing the product to be clearly demonstrated to the consumer. This feature of PET containers makes them comparable to glass containers in this aspect and is actively used by beverage manufacturers as a way to draw consumers’ attention.
At the same time, PET containers are far from being ideal and universal as a packaging solution for all liquid and viscous product varieties. Depending on the packaging composition, ethylene glycol, dimethyl phthalate, formaldehyde and various alcohols may be released into the liquid if the container is not properly stored, and so can catalyst residues which include chemicals such as acetates of manganese, zinc, cobalt, antimony etc. It is important to consider that in case storage conditions and shelf life of drinks packaged in plastic are not taken into account and followed, the migration of toxic chemicals into the liquid increases over time. If the temperature reaches 28°С, the rate at which chemical compounds present in the plastic container are released into the product rockets by a factor of 10. Even a PET container produced right before packing must undergo hygienic treatment – namely rinsing with ozonated water – so that the remains of vapors produced in the process of extrusion can be eliminated. Albeit in small quantities, toxic substances present in plastic, despite not dissolving in cold drinks assuming their proper storage, dissolve in alcohol after a while – who would want a tint of plastic in their drink? PET containers have another unpleasant property – unlike glass, polymers are permeable to gases to some degree, thus letting oxygen pass through the container, accelerating oxidation processes inside it and reducing the shelf life of the product. For the aforementioned reasons, PET containers can be suitable for fast-moving consumer goods with the shelf life of up to 12 months, but cannot be used for aged alcoholic beverages.
Given the above, glass remains the ideal packaging material for food products, especially those with a long shelf life, preserving proper flavor, purity and hygienic characteristics of the product packed. Glass containers with lowered mass are becoming increasingly relevant today. Manufacturers also send to pay particular attention to uniformity of container sides and bottom – sealing, for example twist off capping, involves the possibility of uneven pressure being applied to package sides with variable thickness and the risk of their deformation (cracks, breakage etc.), product loss or the need to stop and wash the equipment. It should be noted that the quality of PET containers is a sophisticated matter on its own: not only does proper placement of stiffening ribs (in particular on lightweight packaging) attract consumers with the container’s original shape, but also determines its stability in the process of packing and on store shelves, and minimizes deformation during transportation.
(End of the article will be published in the next issue.)
Strategic Marketing Specialist
in the food and drinks industry