Hemp is a non-drug variety of cannabis that is grown legally around the world. Although China has been the largest hemp producer over the years, other countries such as Australia and Canada are catching up. Plastic is broadly defined as “a substance that can be moulded or shaped”. In general, ‘plastic’ refers to petro-chemical based substances. Oil is the basis for most plastic production and is an unfortunately limited world resource. Hemp Plastic is therefore any mouldable material that contains hemp.
The first known hemp plastic was developed by Henry Ford. The famous pictures and film of Henry Ford striking a model-T with an axe and it bouncing away showing the potential strength of fibre-based composite plastics – with the exact nature of the material is not known.
Polypropylene (PP) is the most common plastic found in manufacturing today. Hemp plastic was used the first time to make the ‘High-Fly’ Frisbee. Global annual plastic consumption has grown from somewhere around 5 million tonnes in the 50′s, to a huge 100 million tonnes in recent years. One tonne of plastics is equivalent to 20,000 two litre drinks bottles or 120,000 carrier bags. A typical household dustbin includes about 7% plastic materials.
Although a significant proportion of PP is used in fibre production, the remainder is nearly all used in injection moulding. Blending PP with hemp fibres however – whilst improving the strength and heat resisting properties of the material – is a generally more expensive choice.
It is only recently (2011) that new and larger production facilities have paved the way for cost-efficient manufacture of hemp reinforced PP, Polyhydroxybutyrate (PHB) and PolyLactic acid (PLA). A 50% hemp content is usual in these plastics but up to 80% can be used in some materials. Using PLA to blend with hemp produces a 100% biodegradable material.
Hemp plastics in their various forms can be used to manufacture:
- GPS units
- Electrical points
- Cookware handles
- Railway industry
- Water supply materials
- Gardening Equipment
- Many other household items
If PC/ABS, PP reinforced glass-fibre and heat-resistant ABS materials are required, hemp is not only superior but more cost effective. Hemp plastics can be manufactured to a high flame-retardant standard using less of the toxic chemicals commonly used in regular plastics. Some types of hemp plastic can now be made from rice starch which are being investigated for blow-moulding applications. With the manufacture of plastic bags and bottles out of hemp plastic a prospect for the near future. Right now starch (from corn) is the best and most widely used source.
Granular forms of hemp plastics have only become available relatively recently, with rapid growth now expected in the hemp plastics industry – especially with oil reserves reducing and prices increasing every day – hemp crops are sustainable with production prices stable. New global policies for CO2 reduction and non-oil dependence support the use of these materials.
Machinery used to manufacture conventional plastic products (injection moulders) can be used to mould hemp plastics too. Check out www.hempplastic.com to see a didgeridoo made from 100% hemp! Without glues or resins, this material is extremely strong. The commercial potential for these patented innovative plastics has not yet been discovered. It is possible within the next decade the car you drive will be strong enough to withstand a bump, just like the demonstration on the model-T that Henry Ford showed over 80 years ago!