Very Thin Medium Density Fibreboards (MDF) with Paperboard-like Properties as Reusable Packaging Material Folie 1 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Current situation Market data for cardboards for packaging (Germany) ▫ growth for period 2008 – 2012 of 12 %, ▫ production in 2012 of 10.5 mill. t of paper, card- and paperboards for packaging purposes, ▫ assortments and shares: ‐ brown paper and paper for corrugated boards (69 %), ‐ cardboard (27 %), ‐ mill board (1 %), ‐ wrapping paper (3 %). Market of packaging material shows great potential! Also for wood based panel industry? Folie 2 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Current situation Calculation of production factors for 1 mm MDF in comparison to 1 mm cardboard. ▫ Thin MDF as substitute for cardboards as packaging material offers following advantages: ‐ savings in process water (¾ and more), ‐ lower energy consumption, ‐ omitting process chemicals, ‐ lower amortisation costs. production costs are possibly lower, very good carbon and water footprints. Folie 3 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Problem Thin MDF are not suitable for the same applications as conventional cardboards for packaging purposes. Problem: ▫ Product properties, ‐ inadequate foldability, ‐ lack of recyclability. ▫ Production technology, ‐ laying of fibre mat, ‐ accuracy and speed of hot-press. Folie 4 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Objective Development of “dry cardboard” ▫ possible to manufacture with state of the art MDF-technology, ▫ with grammages of 300 – 800 g/m², ▫ applicable as packaging material, ▫ guaranteed recyclability in waste-paper stream, ▫ acceptable foldability, ▫ comparable strength and stiffness in comparison to wet-process cardboard, ▫ ecological and economical advantages. Folie 5 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Approach Technological adaption ▫ pneumatic-mechanical mat laying, ▫ adapted press parameters (temperature, time, pressure). Raw material ▫ fibre pulp ‐ MDF fibres with modified pulping conditions, ‐ addition of differently conditioned recovered paper, ▫ additives ‐ omitting conventional thermosetting condensation resins, ‐ use of natural binders such as starch, proteins. Folie 6 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Materials Fibre pulp ▫ Raw material: Scots pine and recovered paper, ▫ Digester cond.: 160 °C for 3-4 min., ▫ Defibrator: 12 inch laboratory refiner, ▫ Grinding gap: 60 µm, ▫ Driving speed: 3,000 rpm, ▫ Flash dryer temp.: 90 °C. Folie 7 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Materials Application of additives ▫ additives: starch, protein, wheat flour, PVAc, ▫ application: blowline, ▫ content: 10 % to absolutely dry mass of fibres. Additive Recovered paper content / % 0 10 20 30 50 Starch St_0 St_10 Protein Pr_0 Pr_10 Pr_20 Pr_30 Pr_50 Wheat flour Wf_0 Wf_10 PVAc PV_0 PV_10 Folie 8 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Technology Mat laying with Airlaid technology Folie 9 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Technology Mat laying with Airlaid technology Folie 10 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Technology Production parameters ▫ grammages: 250 – 600 g/m², ▫ target density: 700 kg/m³, ▫ cardboard layer: single- and multilayer, ▫ MC fibre mat: rewetted to 13 %, ▫ spec. pressure: 5 – 10 bar, ▫ press temp.: 170 – 210 °C, ▫ press time factor: 10 – 15 sec/mm. Folie 11 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Characterisation Cardboard properties ▫ thickness DIN EN 20534 ▫ mass per unit area DIN EN ISO 536 ▫ burst index DIN 53141-1 ▫ bending stiffness DIN 53121 ▫ folding behavior DIN 55437-2 and DIN 55437-3 ▫ recyclability PTS-RH 021/97 and INGEDE-Methode 13 Folie 12 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Characterisation Folding behaviour ▫ according to standard only differentiated between pass / fail test, Method to assess folding behaviour was established. 10 very good (passed test) … … … … 1 very poor. Folie 13 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Results Burst index with respect to additive wet-process cardboard Folie 14 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Results Burst index with respect to recovered paper content / layering wet-process cardboard Folie 15 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Results Bending stiffness with respect to recovered paper / layering wet-process cardboard Folie 16 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Results Foldability with respect to recovered paper / layering wet-process cardboard Folie 17 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Conclusion Dry cardboards are feasible to manufacture with ▫ optimized raw material combination, ▫ adaptation of mat laying and optimising pressing process, ▫ excellent mechanical properties, ▫ fully given recyclability, ▫ acceptable foldability until now only in multilayer. Folie 18 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Acknowledgement The presented work was supported by the German Federal Ministry of Economics and Technology at the decision of the German Bundestag (IGF: 16911 BG). Folie 19 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Contact persons Institut für Holztechnologie Dresden gemeinnützige GmbH ▪ Tino Schulz [email protected] +49 351 4662 263 ▪ Christoph Wenderdel [email protected] +49 351 4662 256 ▪ Detlef Krug [email protected] +49 351 4662 342 Papiertechnische Stiftung Heidenau ▪ Alf-Mathias Strunz [email protected] +49 3529 551 684 Folie 20 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel Thank you! Folie 21 57th International Convention of Society of Wood Science and Technology, Zvolen, June 23-27, 2014 Christoph Wenderdel.