Projects

Principal Investigator

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Abstract

Triggered by the reduction of fossil resources consumption and CO2 emissions, and by the need to reduce the ecological impact of oilbased plastics and industrial wastes, the PACK4COMPOST project proposes to explore new routes for the production of new biomaterials and for their processing into packages which can be composted together with the packed food. The current bottlenecks which hamper the delivery of such packages to the market are the high cost and low processability of existing biodegradable plastics, the empirical design (test and error method) of the package, the lack of knowledge of the structure-properties relationships of the package and of the structuring of materials during their process. PACK4COMPOST proposes to scientifically address these issues for the specific case of coffee packaging. Novadelta S.A. will first help the research team in targeting the packaging materials and process to be studied in this project. Conventional and non biodegradable materials and packages used by the industrial partner will be extensively characterized. The package production will be reproduced in the lab for a better characterization of the process. PHA (polyhydroxyalkanoates) are potential biodegradable alternatives to traditional packaging materials, but are still expensive since they are obtained from pure cultures of particular microorganisms. Team members at REQUIMTE propose to use a fully integrated 3-stage PHA production process previously designed [1-6] where mixed microbial cultures will be optimized to tailor the copolymer structure. PHA rheological properties (in shear and extension) will be systematically determined at IPC in order to establish new relationships between the macromolecular structure and the physical properties. An output from this fundamental study will be the delivery of PHA with optimized processing characteristics approaching those identified in the first task. The gas and water barrier properties of the PHA will be improved by mixing the bioplastic matrix with micro or nanofillers as shown recently by the research team [7-10]. The team at IBB has recently developed a technology to produce high added value cellulosebased fillers from wastes of the beer industry [11,12]. This work will be pursued to deliver a new set of fillers with different sizes and aspect ratios in order to tune the final barrier properties of the package, as such geometrical parameters will affect the package structuring during the processing. The compounding of these fillers with the optimized PHA and their transformation into films and sheets will then be studied using a mini compounding-extrusion line equipped with in-line structural and mechanical characterization dies. This unique set-up which is capable of processing tens of grams of material has been developed at IPC, and will critically contribute for achieving a successful formulation through the determination of structure-process parameters-product properties relationships without requiring large amounts of costly materials. Final films and sheets properties (thermal, mechanical, gas and water barriers) will be characterized at IPC and IBB. Materials provided by the industrial partner as well as commercial transparent plastics (for in-line structural and particle imaging characterization) will first be used to assess processing parameters effects on the packaging final properties and revisit the crucial issue of nano fillers used as processing aids [27]. The package (sheet plus film) functionality will be determined at IBB in terms of sensitivity to water and to microbial spoilage, degradation, and shelf life extension of the packed food. Correlations between such food properties, physico-chemical characteristics of packages and raw materials properties will be established, thus significantly contributing to a better understanding of food preservation mechanism. The multidisciplinary research team of PACK4COMPOST will demand a specific effort in project management to be addressed in a specific task. The merging of industrials, polymer processing experts, food scientists and chemical engineers, all focusing on the design of a tailored biodegradable package for a well targeted food application, is seen as the key to deliver a prototype. This integrated approach will bring novelty to the different fields connected by PACK4COMPOST, namely the unraveling of chemistrymechanical properties relationships in PHA, and the interplay between film properties, film formulation and processing conditions. The scientific contribution of PACK4COMPOST is mirrored in the 7 papers currently foreseen. The use of conventional processes (film/sheet extrusion, scalable fermentation processes) throughout the project is seen as a positive asset of the purposely proposed research strategy. Last, 2 students will be trained within this project, who can be seen as potential vectors of the direct transfer of the PACK4COMPOST outputs to the industrial partner.