MDV’s experience in supplying speciality substrates to the label and tag industry and Tech Folien’s expertise in producing PE and PP blown films has led the company to define the requirements of an oxo-biodegradable film which could be used in the label industry.
It has to be resistant to tear; transparent, white or colored; degradable in a controlled fashion; printable by most conventional methods including thermal transfer; exhibit sufficient stiffness in higher microns for tag applications.
In other words, it should be a normal PE/PP film with the added advantage of a built-in ‘trigger’ which would start the degradation process according to the requirement of the customer. Hence BioStar, a family of polyolefine films available in thicknesses ranging from 10 micron to 400 micron, and which begins to degrade after a specified period, be it six, twelve, eighteen or twenty four months, after exposure to ordinary light.
The principle utilised in the production of BioStar is that the addition of certain Organo transition metal complexes to the polymer will catalyse the auto-oxidation of PE. The oxidation process results in a drastic reduction in molecular weight and introduction of carboxylic acid functional groups into the polymer chain.
As conventional biodegradable and compostable film have been around for much longer than oxo-biodegradables, there has been attention and time devoted to setting industry standards as well as obtaining environmental friendly classifications. However, their usage has been limited to food packaging applications, especially where there is certainty that the product will fly off–the-shelf (eg potato bags).