Novel biobased thermoplastic foams

Transcription

1 Novel biobased thermoplastic foams BIOMATERIALS Towards Industrial Applications Startup Sauna, Espoo Otaniemi Tero Malm VTT Technical Research Centre of Finland

2 2 Outline Motivation Introduction - Thermoplastic foams PROFOAM - project Future work

3 3 Motivation Why biobased thermoplastics? Need to decrease our dependency on fossil oil Biobased polymers are sustainable Why to foam? With microcellular foaming technology it is possible to: - Reduce weight - Reduce material usage - Reduce cost - Enhance some properties e.g. impact resistance, ductility, fatigue and insulation (thermal and sound) Thermal insulation saves heating/cooling energy. Lighter vehicles consumes less fuel etc. Using CO 2 as physical blowing agent is safer, cheaper and sustainable compared to HC or CFC related gases

4 4 Foaming phenomena Introduction - Thermoplastic foams BA Polymer One phase system Diffusion and dissolution Foam density Fast change in thermodynamic stability (P, T) High density > 700 kg/m 3 Nucleation Cell growth and stabilization 200 kg/m 3 < Medium density < 700 kg/m 3 Low density < 200 kg/m 3 Cell density Conventional Cell size > 300 µm Cell density < 10 6 cells/cm 3 Fine-celled 10 µm< cell size < 300 µm 10 6 < cell density < 10 9 cells/cm 3 Microcellular Cell size 1 µm - 10µm 10 9 < cell density < cells/cm 3 Nanocellular Cell size < 1 µm Cell density > cells/cm 3

5 5 Introduction - Thermoplastic foams Examples of use Packaging: food, consumer goods Construction: thermal and sound insulation Automobile: bumpers, structural parts Sporting goods, soles, floats Which are categorized EPS = Expandable polystyrene EPP, EPE = Expanded polypropylene or polyethylene XPS = Extruded polystyrene Injection foam molded parts termisol.fi ford.com artekno.fi epsira.fi finnfoam.fi arpro.com crocs.fi

6 6 Introduction - Thermoplastic foams What is needed to make thermoplastic foams? Right material(s): Polymer (foam grade good melt strength) Blowing agent: Chemical Blowing Agent (CBA) or Physical Blowing Agent (PBA) Nucleating agents Other additives Right equipment Use of PBAs needs special pumps and good sealing Right processing conditions Optimum foaming temperature can be very narrow Large pressure drop rate at die is favorable in extrusion foaming

7 7 PROFOAM Promoting Functional Biobased Foams PROFOAM project aims at promoting the implementation of fully bio-based foams in current synthetic foam applications Tekes funded project

8 8 PROFOAM Promoting Functional Biobased Foams Implementation of foaming equipment from batch to pilot - Batch foaming. Overall foamability of biopolymers with CO 2 can be evaluated with less than 10 g of sample - Laboratory scale extrusion foaming. Foaming conditions in continuous process can be evaluated with 2-5 kg of biopolymer - Pilot scale tandem extrusion foaming. Foamed sheet and board can be produced for industrial testing purposes with kg of biopolymer

9 9 PROFOAM Promoting Functional Biobased Foams Extrusion foaming of polylactic acid (XPLA) PLA = Biobased, compostable and readily available Disadvantages: High density 1,25 g/cm 3 Brittleness, low ductility and service temperature Poor melt strength Sensitive to hydrolytic and thermal degradation Slow crystallization rate Results: Batch: foamable with CO 2, lowest density ~80 kg/m 3 without additives Lab scale: With filament die lowest density ~35 kg/m 3 Pilot scale: foamed sheet with density 45 kg/m 3. Chain extender to increase melt stength, talc to help nucleation (PS with CO 2 and EtOH 35 kg/m 3 )

10 10 PROFOAM Promoting Functional Biobased Foams Particle foam process Expandable Polylactic Acid (EPLA) Micropelletized PLA Impregnated with CO 2 Lowest density 24 kg/m 3 Traditional steam chest molding machine needs to be modified for PLA molding

11 11 Future Work VTT have facilities for: Extrusion foaming Particle foaming And we are ready to help in any foam application. Biobased or traditional thermoplastics Any additional questions. Please contact: Tero Malm Mobile:

12 12 VTT creates business from technology