Rigid Packaging Bio-Alternative for HIPS Sheet By Volker Siebott JC Hagen GmbH Vienna, Austria bio-plast SHJ 700 thermoformed on Kiefel thermoformer Hips Sheet Grade - Supply Situation One might think that gas and oil exploration countries always have an ample supply of polymers. With a population of more than 71 million the supply situation is anything but balanced in the Islamic Republic of Iran. Besides a significant lack of refining capacities for petrol, Iran has also been a net importer of polystyrene resin in recent years. The country exports huge quantities of crude oil, in particular to Korea, and receives the refined products in return. Rather than expanding the refining capacities within the country a long term strategy led to the development of bio-plastics as an alternative industry. Based on corn starch and other renewable materials the plan will help to keep farmers employed and reduce the trend of urbanization which, at 68%, is already a major concern of the government. With an estimated population of 13.1 million the capital Tehran is the 21 st largest city in world. Development of a Biodegradable Alternative: SHJ 700 In 1999 the University of Tehran began developing a compound with the aim of replacing HIPS applications, in particular in sheet extrusion, with starch alternatives. The developments led to a compound called SHJ 700 with superior properties: the material is heat stable up to 120°C, microwaveable, dish washer proof and good for deep freezing. Yet the composition has a renewable content of 83%, primarily corn starch. Beeswax is a truly natural product but most likely never heard of as a plasticizer for sheet extruded products. The small content of non-renewable materials are calcium stearate, an ingredient of the food manufacturing industry (a hard surface coating for candies) and some biodegradable co-polyester. Other bio-polymer manufacturers are even working on this co-polyester to develop a bio-based version which would in future raise the renewable content of this composition even above 90%! The commercial compounding plant of SHJ 700 today has a nameplate capacity of 30,000 tpa. In total 12 decentralized factories operate sheet extrusion and thermoforming 12 bioplastics MAGAZINE [02/11] Vol. 6
Cellulose 6% Bees Wax E901 2% Co-Polyester 10-12% Renewable Resources 83% Nonrenewable Resocurces 17% Starch based on Corn 75% Calcium Stearate E572 5% machinery all over the country. A range of more than 40 standard finished articles can be found in the market today. The main focus is on disposable and catering products such as hot and cold drink cups, bowls for soups, all kinds of fast food containers, plates and trays. Lately yoghurt cups and meat trays were also added and these bio-degradable thermoformed containers can be found in supermarkets for day to day packaging applications as well. The clear intention to cover export markets with bioplast compound led to the decision to establish a modern compounding plant in the Jebel Ali Free Trade Zone in the United Arab Emirates. Construction of the plant is almost complete, adding another 15,000 tpa capacity for sheet extrusion compound. Further expansions are planned in Turkey and Eastern Europe. To penetrate the European market, direct food contact certification according to 2002/72/EEC has been successfully applied for. Of course the compostablility according to EN 13432 is considered to be essential; bioplast SHJ 700 has been tested by Organic Waste Systems in Belgium and consequently been given the OK COMPOST award by AIB-VINCOTTE under number O 10-441-A . In order to successfully introduce bio-plast in Europe it was essential to prove that the compound was easy to process on standard plastic machinery. For this reason extended sheet extrusion trials took place at SML Maschinengesellschaft mbH in Lenzing, Austria. Roll stock with different thicknesses was subsequently thermoformed into cups, as well as trays, on Kiefel thermoformers. Cycle times achieved were well above 30 cycles per minute using HIPS and APET moulding techniques. This ensured that processors will not face additional investment for new moulds when thermoforming sheet made out of SHJ 700. An injection moulding grade of the SHJ700 series is also available – applications are biodegradable cutlery, clips and hooks for horticulture, re-useable drinking cups, containers with lids, and others. www.bio-plast.com bioplastics MAGAZINE [02/11] Vol. 6 13
