For cold water grade temperature 20°C.

Moisture content of manufactured PVOH rolls is controlled. The produced rolls are packed using vapour proof barrier foil. Once the film is removed from the packaging the moisture content of the film will vary depending on both humidity and air temperature.

Cold water soluble grade at 20°C after 72 hours.

PVOH is a hydrophilic film and has little static electricity when compared with normal plastic polymer film such as polyethylene. When using PVOH there is no degradation of the workability of the film caused by static build up during packaging. In addition, no dust sticks to the rolled film.

Cold water film: 20°C 65% RH: 1 ~ 8 x 108   20°C 45% RH: 1 X 1011

Polyethylene: 23°C 50% RH: 1 x 1014 ~ 1016

Plastics have almost exclusively been derived from the products produced by the petrochemical industry based on crude oil feed stocks. Over the last 25 years the world has seen an inexorable rise in the use of plastic materials, which is broadly utilised in all areas of the human living environment. Over this time period plastic packaging has seen the largest growth within the industry.

The development of non-petroleum based commercial plastic products that to all intents and purposes act like traditional plastic but are capable of breaking down into their original organic components are being looked at with increasing commercial promise. Most biodegradable plastic takes weeks, months and even years to break down into their original organic components. Indeed the lifecycle of a biodegradable plastic may be inherently built in to the manufacturing process so that, for example, a plastic can be engineered to last for many years before biological breakdown takes place.

Major companies are currently involved in a global market that is now estimated to be worth approximately $25 billion per year. In recent times a key testing ground for biodegradable packaging was seen in the 2000 Sydney Summer Olympics. The food vendors for the Games were only allowed to use biodegradable and re-cyclable packaging. This meant that more than three-quarters of the 660 m/t of waste generated each day at the Games was capable of being composted instead of sent to landfills So from here the main driver to public acceptance would be through Government legislation. For without Government mandates, the price differential seen at two to one, will slow down acceptance and usage in the short term.

It is believed that over time a biodegradable packaging industry offering competitive prices, based on true environmental costs such as greenhouse gas emissions, energy usage in production and total lifecycle costs are taken into account more accurately. Some corn-derived food packaging plastics require almost one-third less non-renewable energy to produce, than packaging made from more conventional sources such as petroleum-based polypropylene. Biodegradable packaging represents a major step forward when compared to the synthetic alternatives currently available.

The two main areas for the use of biodegradable plastics are:

1.composting
2.agriculture

The composting route includes household and commercial food waste, garden waste, horticultural packaging and disposable cutlery. Agricultural use seen in, so called, crop over-mulch film.

These applications are identified as the most suitable for biodegradable products, since after their use it is not practical or hygienically and environmentally safe to recycle them conventionally. Biodegradable plastics are not suitable for all applications where recycling and landfill are seen as the final route for these products.

Recycling

Under current conditions biodegradable plastic is unsuitable for products that can otherwise be recycled at the end of its life. Recycled products cost nothing or little to the consumer, whereas biodegradable products do. Any form of impurities in a product, whether it’s a paper label or a biodegradable additive, will increase the environmental and economical cost of recycling and reduce the value of the recyclate.

Recyclable/Degradable

Biodegradable formulations contain products that act as the trigger mechanism for the degradation of the biodegradable plastic. This is normally activated after recycling, therefore causing the second life product to continually weaken or degrade throughout its life. It is therefore doubtful that a product can be both degradable and recyclable. Indeed all recycled plastic and plastic utilised for recycling must be kept completely free of biodegradable plastic to ensure the continued success of recycling.

Landfill

The current view is that biodegradable plastic is unsuitable for any products that are sent to landfill.

Ideas claiming that biodegradability extends the life of a landfill site have yet to be proven. Landfill site conditions are not often suitable for the degradation to occur as exampled by some landfill sites containing newsprint, which is more than 30 years old and has been recovered from landfill sites still in tact. Introducing biodegradable products into landfill sites may lead to instability of the landfill site, causing potential problems after the landfill had been capped and sealed and used for other purposes. If, for example, most of the packaging of a landfill site, of which 4% is polythene, and this polythene was biodegradable, then over a 20 or 30 year period, the disappearance of this biodegradable polythene from a capped landfill site would create a void of some 10 – 15% of the total landfill. The consequences of such a site that had been capped and subsequently developed into a housing estate are clear to imagine.

Currently biodegradable plastic is suitable for products that will be composted and not go into landfill or being recycled where the effects of biodegradability on the recyclate are unknown. Biodegradability is expensive but acceptable environmentally for some specific applications. The overall situation at present is that it is generally undesirable.