The materials for food packaging on the market have different characteristics, quality, disposal costs and recyclability

In the world of food packaging we find extremely different raw materials, some of them, such as paper and glass, have a thousand-year history, while plastic and aluminum have a more recent history.

We do not want to deliberately enter into a marketing duel on the preference between one material or the other, but we would like to analyze some aspects concerning the conservation of the contained assets, the durability of the packaging, recyclability.

In truth, to these analyzes we should add that relating to the compared production costs and the environmental impact on logistics, which will be addressed elsewhere.

If we take a look at the past we can say that glass was the main material of the packaging with which liquid foods, milk, wine, spirits, oil were contained and other foodstuffs, while starting from the economic boom of the 1960s, mineral water and soft drinks had also found their share of the market through packaging in bottles.

As far as metal food boxes are concerned, we can refer to the 19th century as the beginning in America and England of the first industrial productions, although the costs to make them were very high and canned food was therefore a luxury for the few.

To push their diffusion, however, came the world wars, as the armies found it convenient and logistically useful to entrust the soldiers' rations to this type of packaging.

With the advent of aluminum cans, a widespread diffusion of food and drinks packaged in soft metal began in the mid-50s of the last century .

As far as the use of paper packaging is concerned, we have to get to the mid-50s of the last century to see the start, in Sweden, of the first packaging for food liquids in cardboard and plastic film packages.

Since 1973, when the Du Pont company patents PET, we can say that large-scale food packaging was born, with the intention of eroding quotas market to glass ones.

If we want to make a comparison of the physical and chemical qualities of the main food packaging, we can list some general comparisons:

Possible transfers of packaging substances

• Glass: sodium and calcium already present in food

• Plastic: components of additives especially if there is fat or alcohol

• Paper or Cardboard: additives and colorants

• Metal: Tin and lead within the legal limits. Toxic substances from paints (at high temperature)

Impermeability to liquids, gases and microbiological agents

• Glass: 100%

• Plastic: variable depending on the polymer

• Paper or Cardboard: only if there are no surface abrasions

• Matallo: only if there are no surface abrasions

Corrosion of the packaging

• Glass: Only hydrofluoric acid and alkaline solutions with a Ph higher than 8

• Plastic: can release microplastics at the bends

• Paper or Cardboard: attackable by insects and mice

• Metal: generated by any imperfections of the structure

Sterilisability

• Glass: 100% dry and wet

• Plastic: with special bacteriostatic additives

• Paper or Cardboard: during packaging with hydrogen peroxide or UV or chemical agents

• Metal: 100% even at high temperatures

Transparency

• Glass: perfect with clear glass

• Plastic: depends on the polymer, difficult with recycled HDPE polymers

• Paper and Cardboard: no

• Metal: no

Actinic light protection

• Glass: good in the colored vertices

• Plastic: good with specific additives

• Paper or Cardboard: opaque

• Metal: opaque

Sanitization

• Glass: excellent

• Plastic: disposable to be recycled

• Paper or Cardboard: disposable to be recycled

• Metal: disposable to be recycled

Recyclability

• Glass: continuous and without degradation. Economical only with returnable vacuum

• Plastic: possible a certain number of times with some qualitative degradation. The recycling of polylaminates is difficult

• Paper and Cardboard: recyclable with degradation. The recycling of paper-plastic polylaminates is difficult

• Metal: good

In conclusion, an economic comparison of food packaging will be added to this analysis according to the durability of the product on the shelves and the cost of recycling or disposal of packaging at the end of its life, as well as the environmental impact of both production, logistics and the circularity or otherwise of the waste.

Automatic translation. We apologize for any inaccuracies. Original article in Italian.