Materials Sunflower
Materials Sunflower Power By Karen Laird Golden Compound creates innovative biocompounds from sunflower hulls “Why do we use sunflowers? Because they have proven to be an amazing source of natural fiber”, said Marcel Dartée, general manager of Golden Compound, a start-up company headquartered in Ladbergen, in northern Germany. “Although, to be more precise, it’s actually the fibers derived from ground sunflower hulls that are used in our plastic compounds.” As a side product of the sunflower oil industry, sunflower hulls have traditionally been regarded as a product with little to no value. For the most part, they are burned as fuel for the crushing plants or serve as low-quality roughage for cattle and sheep. Yet, as Dartée pointed out: “There is an infinite supply of sunflower hulls. They are a sustainable source of natural fiber that, moreover, in no way interferes with the food chain.” From pilot to plant The idea for using sunflower hulls to create a new type of biocompound originated with a German company called SPC, which had close ties with a sunflower oil mill. SPC specialized in the development and marketing of processes and technologies to produce biomaterials. Cargill saw the potential of the idea and the two companies, both of whom were already active in the sunflower business, established the 50/50 joint venture company Golden Compound GmbH in June, 2014. The description of the activities of the new company was relatively straightforward: based on technology provided by SPC, the object of the company was to develop, manufacture, and commercialize a range of biopolymers reinforced with natural fiber derived from sunflower seed hulls. The initial pilot plant was up and running by October 1st of last year, and has since been scaled up, to reach a production capacity of 2.5 tonnes/year today. The company is planning to construct an industrial-scale facility, the size and site of which still remain to be determined. The new compounds have been launched under the name S 2 PC, short for Sustainable Sunflower Plastic Compounds and are available as natural-fiber reinforced PP or PLA compounds. The company also offers compounds based on recycled post-consumer PP. The compounds currently on the market have been especially developed for injection molding; other grades are under development. While the natural color of the compounds is dark, with a visible fiber structure, the fibers are easily rendered invisible by adding regular carbon black to the formulation. At the Fakuma trade show in October (Friedrichshafen, Germany), which marked the first public appearance of Golden Compound, various products were on display at the stand, including a pure black desk tray made from the new compounds. 30 bioplastics MAGAZINE [06/15] Vol. 10
Materials Excellent processing properties According to Dartée, the materials, which the company has tested in various markets, have met with a positive response. “The results have been good,” he said. “The compounds have been successfully used in a number of office furniture applications, as well as in office supply products.” Part of the positive response is at least due to the fact that to date, all conversions have been made at equal or lower cost. Yet economics is not the only answer. “Sunflower seed hulls have inherent foaming properties,” explained Dartée. “This considerably enhances the filling behavior, especially in thick-walled products.” At the stand at the Fakuma, he displayed two identical products, one molded with S 2 PC, the other with conventional material. The difference was clearly visible: the product molded with conventional material showed sink marks; the S 2 PC product did not. “There is no need to overfill the part or for high back pressure. This is the result of the very slight foaming action that occurs. An additional benefit is that, due to the excellent heat dissipation properties of the material, the cycle times are also reduced for these thicker products.” Golden Compound’s S²PC materials also have a lower density and are lighter in weight compared to, for example, glass-filled compounds. According to Dartée, combinations are also possible. “Using a 30 % loading of sunflower hulls together with a 20 % glass fiber loading in PP, can replace 40 % glass fiber while retaining all mechanical properties. Not only does the density go down – so less weight – but the cycle time is also reduced,” he said. The proof of the pudding is in the eating The S 2 PC materials also provide the stiffness needed to replace materials, such as PS (in the case of the desk tray), or even PA. At the Fakuma, Golden Compound was showcasing examples of office furniture in which the new compounds have replaced the original nylon used in, for example the back support of an office chair. In fact, the company has partnered with Germany-based furniture manufacturer fm Büromöbel, which has now incorporated S 2 PC into various of its products. “fm Büromöbel wanted to improve the environmental footprint of its office furniture product range without sacrificing on quality,” said Ulrich Meyer, managing director of fm Büromöbel Franz Meyer GmbH & Co. KG, Böse. “S 2 PC, made with plant-based remnants, offers us both ecological and economic benefits”. The customer response has been extremely positive, he reported, as the products offer sustainable benefits at no additional cost. Next to the office furniture and supplies market, Golden Compound is also looking at the opportunities offered by the horticultural industry – and the automotive industry, where the new S 2 PC compounds could easily replace glass-filled PP in various non-visible components. Yet, the proof of the pudding is in the eating. As Dartée emphasized, what it ultimately comes down to is performance. If customers understand, and are convinced that the product offers superior benefits, at an affordable price, they will be prepared to make the switch. “Not because S 2 PC is a sustainable choice, but because it works.” www.golden-compound.com bioplastics MAGAZINE [06/15] Vol. 10 31
