U. Gohs (gohs@ipfdd.de), H. Dorschner, G. Heinrich, M. Stephan, U. Wagenknecht (Leibniz Institute of Polymer Research) R. Bartel, O. Röder (Fraunhofer Institute of Electron Beam and Plasma Technology) Requirements on Electron Accelerators for Innovative Applications in Polymer Industry
Contents 1. Introduction 2. Interaction of electrons with matter 3. Electron treatment of polymers 4. Trends 5. Requirements on electron accelerators 6. Conclusion
1. Introduction well established for about 50 years uses energy input of accelerated electrons for generation of ions and excited particles (nonthermal applications) local and temporal precise heat generation (thermal applications)
2. Interaction of electrons with matter
3. Electron treatment of polymers cross-linking transformation of polymers into three-dimensional network (C - C) changed chemical, mechanical and thermal properties product quality is controlled via dose applications - cables, pipes and tubes, form parts Studer HARD (Switzerland): 10 MeV / 200 kw
3. Electron treatment of polymers electron beam curing fast transformation of reactive organic liquids into a solid polymer network applications - coatings on glass, metal, paper, wood industrial floor at VW in Dresden Scannery Holztechnik (Germany): 280 kv/ 20 kw
4. Trends compact powerful electron accelerators for: in-line modification of new and recycled plastic pellets and powders continuously modification of thermoplastics during plastic processing AEB (USA) 150 kv / 25 ma size: 30 x 30 x 40 cm FEP (Germany) 120 kv / 160 ma size: 40 x 70 x 1500 cm LINAC (France) 3-10 MeV size: 80 x 80 x 1600 cm
4. Trends new technological effects on polymers via: electron treatment in reactive gas atmosphere generation of different functional groups in polymers electron treatment at elevated temperature higher yield of cross-linking or polymerization coupling of electron accelerator, reactive gas system and plastic processing technology
4. Trends modification of new and recycled plastic pellets and powders Polypropylene and rubber meal from recycled tires production of thermoplastic elastomers
4. Trends modification of new and recycled plastic pellets and powders - result 350 Comparison of material data relative values [%] 300 250 200 150 100 50 0 untreated-pp/rubber meal blend treated PP/rubber meal elastomer alloy E-modulus tensile strength break stretching
4. Trends electron treatment at elevated temperature: cross-linking of polyethylene
4. Trends electron treatment at elevated temperature - result Scanner of ELV-2 (0,6-1,5 MeV; 20 kw) single screw plastic extruder on conveyor system inclusive water bath, granulator and sampling system
5. Requirements on electron accelerators compact electron accelerators due to future in-line application compact electron exit window with shaped beam geometry due to direct modification of strands and form parts special oxide layer coating on titanium foil to withstand reactive gas atmosphere at elevated temperature water cooled electron exit window without any air cooling to avoid cooling of melted polymers and influence on particle flow under electron exit window maximum area density of electron current: about 0,25 ma/cm² results from single path product treatment working time without any interruption: 4000 5000 hours due to established maintenances cycles in polymer processing
6. Conclusion compact and powerful electron accelerators are available innovative technological effects have been tested new future applications in polymer processing increased spread of electron accelerators
Ladies and Gentlemen, Thank You for Your Attention! Leibniz-Institut für Polymerforschung Dresden e.v. (Leibniz Institute of Polymer Research Dresden) Hohe Str. 6 D-01069 Dresden P.O. Box 120 411 D-01005 Dresden Phone: + 49 351 4658-0 Fax: + 49 351 4658-284 Internet: www.ipfdd.de e-mail: ipf@ipfdd.de