Aluminium Packaging, an Almost Traditional Congress

Organized by the Italian Packaging Institute, the congress tackled the industry’s hot topics with the contribution of academics, Associations and companies within the aluminium packaging value chain

by Giuseppe Giordano

The success of a technical congress can be measured with the repetitions of the events. If the meeting becomes recurring and every year it grows, with increasingly diversified attendance, this means that the topics dealt with find a match in the life of companies. Papers presented and debates are not only words but study, elaboration and a desire to discover the different multidisciplinary aspects offered by the analysis of the complex relationship which characterizes packaging and its content. The “Aluminium packaging” congress held on February 13th, 2019, in Florence belongs to this class of specialized events. This is the third time that the Italian Packaging Institute promotes this event, always half way through the winter and in the Tuscan regional capital. And for the third time this event was guided by the competence and enthusiasm of Ciro Sinagra, R&D manager, Laminazione Sottile, and vice president of the Institute.
Mr Sinagra is today a reference point for studies on aluminium packaging. His activity has become a hinge between industry, universities and health authorities, combining scientific rigour and a pleasant Neapolitan good-natured and spontaneous spirit.
The ten memoirs presented concerned different topics, from norms to quality control tests to market data and the trend during the past few years of the various sub-segments of aluminium packaging, such as rigid, semi-rigid and flexible packaging. The speakers came from different segments: manufacturers of seals, cans and tubes and of rolled products, converters, trade associations and the academy.
The opening speech by Barbara Iascone of the Italian Packaging Institute presented the industry data included in the report “Packaging in figures – 2017”. The summary of the document (which may be obtained from the Institute) is provided in figure 1.
Providing summaries of all the memoirs is not the aim of this article, which focuses only on those presentations containing an innovative message and a greater commitment for the aluminium industry, for a greater encouragement to elaboration.
This aspect can be found in the remarkably interesting memoir presented by Maurizio Fancinelli from Pelliconi Spa, a manufacturer of seals with a long history of excellence. The company has been producing crown seals ever since 1939 and following a constant growth and careful diversification it is today one of the global leaders in the segment with a production and sales presence in several continents. The range of Pelliconi products which accompany the traditional steel crown seal are pilfer proof, flexible and pull-tab seals which can be opened without using utensils. The last two classes mentioned are based on the use of rolled products in Al-Mn and Al-Mg alloys. For instance, the Pelliconi MaxiP-26 pull-tab seal, an alternative to the classic 26 mm crown corks, is made using aluminium sheets in 5052 alloy, 210 µm, in the H39 extra raw physical state. Pelliconi is one of a numerous group of companies based in Emilia which gave rise to the so-called “Packaging Valley”. Revenues generated by the sale of packaging machines, capping machines, super-fast machines to pack tobacco, chocolate and pharmaceuticals represent a significant share of the national GDP, but above all the segment pursues the objective of being always in the top bracket of technological leaders on a global level.

Aluminium and contact with food
Raffaella Bonacina from Carcano Antonio Spa summarized data and properties of aluminium starting off from the clout of the packaging segment in aluminium consumption in Europe (roughly 17% of 14 million tons a year). Within these values, the production of sheet metal is estimated in about 850.000 tons per year, that is, about 35% of the share of aluminium. The presentation continued with a complete analysis of the different applications of sheet metal, from extra thin foil present in composites for milk and fruit juices to semi-thin sheet for lids and containers. In the second part of the presentation the norms and laws concerning the contact between aluminium and food were expanded.
Giampaolo Barbarossa, Secretary General of AITAL – the Italian Association of surface treatments for aluminium, presented an aspect of aluminium which is unusual for packaging, that is, the possibility of being anodized. If in the first part of his presentation Barbarossa chose to report the results of tests by the National Health Institute on coffee makers and other kitchen utensils, in the second part he outlined the main technical norms regarding anodized aluminium and particularly those which may concern the contact between the anodized oxide (both cold and heat bonded) and food. Anodizing and possibly colouring by impregnation or by electro-colouring are not typical surface treatments for objects or machines which come into contact with food. There is however a possibility for designers to use the versatility of the anodic oxide for objects which may come in touch with food. In this case the design criteria typical of packaging are valid to guarantee a controlled interaction between metal and food.

Innovative spectroscopy for the analysis of aluminium surfaces
Ciro Sinagra did not just act as chairman for the congress, but he also presented an interesting scientific memoir which describes a new investigation technique for the accurate identification of the chemical composition of the surface. This technique is called GD-OES -Fast (GD) Pulsed RF Plasma Source and it is the combination of Glow Discharge with the analysis using Optical Emission Spectroscopy. The GD-OES method provides rapidly the profile of the surface and the elementary chemical composition of solid materials, both of the overall mass of the sample and according to thin layers depending on the depth. Low pressure, high density plasma provides a fast (several nm/s) and uniform sputtering of solid materials. An equipment of this sort has been recently introduced in the laboratories at Laminazione Sottile. If the more than encouraging outlook will be confirmed, we shall be faced with the currently unthinkable results of a revolutionary investigation technique which will allow a better explanation of the behaviour of the metal’s surface with respect, for instance, to thermally sealing coatings or glues, besides defining better the reactions which may occur during contact between metal and food.
An interesting example was described by Sinagra (figure 2). The surface of a sheet made out f 8079 alloy was analysed using the new technique, showing that part of the alloy’s magnesium moved to the surface. The initial contact, for instance, with a liquid (including environmental humidity) in this case does not occur with a layer of aluminium oxide but magnesium oxide, known to be more sensitive to humidity and therefore more subject to volume changes which may affect the sheet’s adhesion to another material a typical situation for aluminium sheets which serve the purpose of providing a tight seal for a plastic container.

As mentioned in the premise, the Florentine congress was a success, no less than the first two editions. However, a shortcoming may be noted, which may not be ascribed to the organizers, but, in general, to the aluminium industry. Metallurgical research is lacking: product innovation almost never includes the technological aspects of the metal. Cans have been manufactured for the past sixty years or so with the same alloy and the same goes for trays and containers, always bound to the same composition and the same physical state. In future years, when aluminium will consolidate its position in the automotive industry even thanks to the development of heat treatment alloys having improved properties, we may hope for a positive contamination between industrial segments which could lead to improvement of the basic materials in an industry such as packaging, among the most sensitive to sustainable innovation.