Lankhorst Yarns has been supplying the compostable horticultural twine Elite Bio Twine, made from the organic raw material PLA, a lactic acid and in this case, plant sugars, since 2009. The company started the development of the compostable twine in 2005 after the company had done previous research in 1993 and 1998. "What is unique about this product besides being compostable is the manner of production," says Joris. "The twine is made in the same way as 'normal' polypropylene twine."
The Elite Bio Twine, dependent on the circumstances, breaks down in industrial compost in 5 to 8 weeks into an unrecognisable, hummus like substance. If there are remains of string left in the soil after the compost phase, these will break down without leaving behind toxins. At the moment there is global scientific research into supporting this with facts.
Growth of Elite Bio Twine
Elite Bio Twine is distributed globally. Since its introduction the sales of organic twine have risen, but it hasn't taken real flight, especially in the Dutch horticulture. If there is no financial advantage for a grower, they won't pay more for it. However, there are various tests this year in large greenhouses in the Netherlands that should provide good results.
Waste processing costs
An extra stimulation could be if waste processing costs go up due to the plastics in the waste. "This would mean the higher price for our PLA twine would be made back in the process. The grower will still have to get used to the manner of calculation, as they generally just look at the purchasing price, not what it provides in the end. Even the string that holds up the entire capital of the growers is only viewed in terms of the purchasing price. We already have enough evidence that composting costs money and the costs for the waste with PLA is lower than the polluted waste with PP twine."
Although Lankhorst Yarns also produces plastic twine, Lankhorst sees Elite® Bio Twine as the twine of the future. "Plastic twine can never be fully separated from your green waste. The plastic you can get out is contaminated with green materials. And there are often still remains of plastic twine in the compost. Maybe just a few percent, but if plastic is being put in the ground year on year the total percentage will increase."
The company will be at the HortiContact in Gorinchem to promote the Elite® Bio Twine and to support the dealers. They can also be found at the GreenTech in Amsterdam.