With biodegradable becoming less of a buzzword and more of a reality in the packaging business, a machine maker has adapted a blow molder for use with corn-based plastics.
Over the past year packaging suppliers have been introducing various forms of biodegradable plastics made from a variety of plants, in the main corn, based on projections that there will be a growing demand for environmentally-friendly packaging.
The switch to biodegradable packaging is driven by environmentally-conscious consumers and recycling regulations. Some companies are predicting that the market will grow by about 20 per cent a year. The development is also being pushed by the recent escalation in the price of oil, which is bringing traditional petroleum based polymers into the same range as the previously more expensive non-oil based packaging.
Lincoln-based Norland Int'l said its Freedom series of small-bottle blow molders can be used with preforms made of polylactide (PLA), a corn-based plastic developed by NatureWorks, a wholly-owned subsidiary of Cargill.
The blow moulder is specially designed for use by small to medium-sized bottled water operations. PLA is compostible.
The Freedom series can produce up to 4500 bottles per hour, depending on bottle size and blow molder model used. Water bottling companies that produce their own bottles can save from 25 per cent to 50 per cent on the cost of bottles, compared to buying pre-blown bottles.
The preforms are manufactured at the NatureWorks plant in Blair, Nebraska.
The Norland blow molders were designed originally for blowing petroleum-based plastics. They have been specifically adapted to handle the PLA plastics.
Preforms made of PET and PLA have different characteristics. For PET, preforms must be preheated to 100C, while PLA preforms must be heated to 75C, saving on energy costs.
While scientists estimate that petroleum-based plastic products require thousands of years to decompose, PLA products are compostible within 45 to 90 days. The compost can then be used to fertilize the next year's crop of corn, completing the cycle of a totally renewable resource.
NatureWorks has said over the past three years it has had a "dramatic" increase in the number of commercial successes of its PLA used to make one form of biodegradable packaging.
NatureWorks, a Cargill unit, developed and produces PLA. Companies such as Treofan in Germany use the PLA to make a packaging film for foods or other products.
Food packagers last year faced price hikes of between 30 per cent to 80 per cent for conventional plastics due to the increased cost of petroleum. With the increases some bioplastics products reached full price competitiveness with the traditional oil-based packaging.