Plastic packaging today has two substantial sectors – shrink wrapping and vacuum wrapping. There are many other kinds of packaging used throughout the world including in them such as skin, blister, stretch and overwrapping methods of packaging to name but a few. Whilst both vacuum packaging and shrink wrapping require the use of either vacuum packaging or shrink wrapping machines, around which a large industry has grown up, it is interesting to consider the historical origins of the industry.
Plastic packaging became popular in the packaging industry at the invention of polypropylene in 1954 by Giulio Natta and Karl Rehn, who managed to polymerise propylene in it’s current form for use in commercial packaging. The Italian company Montecatini, a chemicals company, were among the first to use it in a mainstream format from 1957 onwards when it became more popular.
The invention of polypropylene came before regular cans and pop top aluminium cans became widely available, although the plastic wrapping material was at a premium due to the expensive production methods – such as the required packaging machinery – and time required to wrap objects in the plastic.
Before packaging machines were readily available to the industry, items that would today be shrink wrapped would have been packaged using alternative methods such as injection moulding or blow moulding.
These methods, although predating shrink wrapping, formed the principles that we still use in modern machines. Today packaging machines work on the principle of heating up the shrink plastic to activate a molecular memory which forces the film to return a pre-expanded form, so that it adheres tightly to the product and, when cooled, leaves a stable and secure packaging result.
Automated shrink wrapping machinery was unheard of in the UK and worldwide in the early 20th Century as there were no packaging machines that could conduct this physical process at a fast enough – or successful enough- rate to allow it to be industrialised, so for a long time other packaging methods were used such as cans or paper.
In 1982, when shrink plastic polypropylene was being widely used commercially and the first packaging machines were already in use, there were a series of deaths in Chicago due to packets of over-the-counter drug Tylenol. This drug had been tampered with by a member of the public who was never caught, which led to the demand for tamper proof packaging, in turn leading to the developments of better quality packaging machinery to apply the tamper-proof shrink plastic.
Another development in the journey of the packaging machine came in 2005, when the Producer Responsibility Obligations Regulations came into effect in the UK meaning that companies had to take more responsibility for their waste. These changes meant that any packaging machinery used had to be economical with the material as to minimise waste and save the company money of waste disposal. As well as the UK, these laws were applied to Northern Ireland in 2006.
The future of packaging machinery seems pretty stable, but with recent developments in edible food packaging by a company called WikiPearl – founded by Harvard Bioengineer David Edwards – the packaging machinery landscape may change again soon. WikiPearl uses a skin similar to grape skin or apple skin to package a product with, making it edible and more environmentally friendly than plastic packaging products, although this technology is not yet in regular use.