The following relates to display shrink films which are principally based on polyolefin structures.
The simple truth is that –
“Currently, there are no industrial technologies that result in the production of a biodegradable shrink film in the strictest sense – meaning a film compatible with the market requirements”.
The above statement is taken from the literature published by a manufacturer of oxo biodegradable film – which is held out, not by the manufacturer, it must be said, but rather by certain of the manufacturer’s distributors as being fully compliant.
There is a need to have to understand some definitions in this particular area.
The most valuable is EN 13432.
In simple terms, the above defines that which is biodegradable or not.
Simply, the EU Directive on Packaging and Packaging Waste (94/62/EC) defines requirements for packaging to be considered recoverable. The Harmonised Standard EN 13432 amplifies these requirements with respect to organic recovery and biodegradable packaging. The EN 13432 lays down laboratory test procedures for biodegradability and compostability and for the determination of potential harmful material constituents in packaging and packaging materials. Whenever a packaging product is placed on the market as degradable, conformance with the requirements of 94/62/EC is to be assessed through the use of EN 13432.
Again, simply, oxo biodegradable polyolefin shrink film does not comply with this fundamental standard EN 13432.
A great deal is made of the concept that some attempt is better than nothing at all and, in the same way, that which is being offered represents a valuable route towards the product being more environmentally friendly.
Once more, the truth is that the underlying technology is based on special additives which have indeed been available in the market for in excess of 20 years. Since their first appearance, many doubts have been expressed as to whether these products provide what they promise. Such doubts are still valid, today.
To summarise, a biodegradable Polyolefin Shrink Film must decompose in the presence of bacteria or other micro-organisms under natural conditions producing water, CO2 and biomass, as described by the European Standard EN 13432.
Biomass itself is defined as biological or organic material.
Degradable or oxo degradable materials are no more than polymers derived in the normal way from oil where an additive has been used which allows them to break down, although the basic molecular structure is still maintained.
The film degrades in that sense but there is no change whatsoever in its chemical composition and hence, there is no biodegradation in any meaningful sense at all.
It may well be that biodegradable shrink film is developed at some point in the future.