Injection Moulding
Injection Moulding Biodegradable materials for micro-irrigation systems FAO results published in the “World agriculture: towards 2015/2030” study, show the global increase of crops irrigated area. The study suggests that the irrigated area in the 1997 – 1999 period was 202 million hectares. This figure will rise up to 242 million hectares by 2030. Dripping irrigation systems (micro-irrigation systems) are required due to irrigation growing needs. These systems allow a more sustainable management of the water needed for crops maintenance. Current micro-irrigation pipes, manufactured with polyethylene, are taken to a recycling plant or incinerated in situ after use, depending on each country’s legislation. The amount of plastic waste generated in agriculture by the EU-27 countries, Norway and Sweden in 2008 was 1.243 million tonnes (Mt). 53.6 % of the total was thrown away. On the other hand, the remaining 46.4 % was recovered: 262.000 tonnes (21 %) were mechanically recycled and 315.000 tonnes (25.3 %) were energetically recycled. The amount of waste generated by irrigation pipes and accessories was 200.000 tonnes [1]. One alternative to agricultural plastic waste management is to use biodegradable plastics. Biodegradable plastics are for example in use already for mulch films, plant pots and many more applications. However, until now no materials suitable for manufacturing of compostable micro-irrigation systems have been available. DRIUS project: compostable micro-irrigation system The European project DRIUS Industrial implementation of a biodegradable and compostable flat micro-irrigation system for agriculture applications aims to produce new biodegradable and compostable drip irrigation systems and place them on the market. The developed irrigation systems will be especially used for plant cultivations, such as strawberries and tomatoes, which have shorter growing periods. The advantages of this new system will be: • An alternative to current incinerating and recycling processes. It has to be taken into account that uncontrolled incinerating in the EU is not permitted (The Incineration Directive (Directive 2000/76/EC) (EN. 2000)) and that the resulting recycling is a low quality product due to high contamination and degradation of pipes, which are in contact with soil, pesticides and fertilizers. • Economic saving: elimination of separation, removal and recycling costs, which entails an expenditure of approximately 1,050 €/hectare. Figure 1: Industrial line of micro-irrigation pipe extrusion. Figure 2: Biodegradable pipes coming out of the calibration and quenching baths. Figure 3: Flat and tubular drippers developed in DRIUS. 20 bioplastics MAGAZINE [03/15] Vol. 10
Injection Moulding • Energy saving during the elaboration process as the pipes made with these materials requires lower processing temperatures. • At the end of their lifetime, pipes would be managed as all organic wastes and they will biodegrade in less than 6 months. • A new compostable product will be obtained with an additional value at the micro-irrigation systems endof-life. Its development will allow its management in a composting plant without any need to separate. Project’s results During the project’s first year, the extrusion process was optimized in order to elaborate biodegradable pipes in conventional extrusion lines (see Figures 1 and 2). These pipes can be processed at a temperature 40º C lower than polyethylene, resulting in energy saving and a lower environmental impact. In order to develop these pipes, several commercial biodegradable materials were mixed through physical compatibilisation and chemical functionalisation. At the same time, the synergy effect of these mixtures was studied. The developed pipe consists mainly of PLA (polylactic acid), modified with other biopolymers and additives to achieve the properties required. The percentage of used material from renewable sources is higher than 70 %. During this same period, new moulds were designed to inject the developed biodegradable materials for drippers. Figure 3 shows that results were satisfactory and that the new developments present suitable physical features for its injection moulding processing, creating drippers with the required geometry. Drippers’ geometry is crucial for the micro-irrigation system so that they provide the necessary amount of water for different crops. The companies involved in this project are currently working on improving not only the demoulding process but also the insertion of drippers in the pipes. The DRIUS Project began on 1 st November, 2013 and will run for 24 months. It is funded by the European Commission within the “CIP-Eco-Innovation” Programme (contract number ECO/12/332883). The consortium is formed by Spain’s Technological Institute of Plastics (AIMPLAS); Extruline Systems SL of Goñar, Spain; Metzerplas Irrigation Systems of Kibbutz Metzer, Irael; and OWS NV of Gent, Belgium. Coauthors of this article are Oded Baras, Antonio Bayonas, Steven Verstichel, Chelo Escrig, Raquel Giner. More information / sources [1] Plastic Waste in the Environment, BioIntelligence Service, http://ec.europa.eu/environment/waste/studies/pdf/plastics.pdf By: Maria Pilar Villanueva Extrusion Department AIMPLAS (Technological Institute of Plastics) Paterna, Spain Celebrating 20 YEARS VINÇOTTE, PIONEER & WORLD LEADER IN BIOPLASTICS CERTIFICATION www.okcompost.be Since 1995 YOUR REPUTATION IS MINE. bioplastics MAGAZINE [03/15] Vol. 10 21
