Vaahtorainauksen tutkimus VTT:n tutkimusympäristöissä

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1 Vaahtorainauksen tutkimus VTT:n tutkimusympäristöissä Metsäteollisuuspäivät Savonlinna Harri Kiiskinen, VTT Phone: VTT beyond the obvious 1

2 Foamed water A disaster? VTT beyond the obvious

3 Foamed water A disaster? An opportunity VTT beyond the obvious

4 Why foam technology Two major benefits compared to traditional papermaking 1) Formation sheet uniformity. Practically always good for all fibers Good formation with long fibers. 2) Possibility to highly porous structures a method for raw-material efficiency & new fiber based products. Widens the product property window New product possibilities for wood fibres Insulation, filtering, absorbing, packaging, Material combinations Mixture of high & low density materials

5 Historical perspective on foam forming s Wiggins Teape Radfoam 80 s Piloting & small, full scale production machines 90 s Oblivion / secrecy 2008 New emergence 2015 Preparing for commercial ization Entering production Foam forming is in industrial use for specialty products

6 Fiber foam Multi-phase system Water, air, solid material Fiber suspension + air Surface active agent Typical air content 40 70% Foam stability can be controlled Typical bubble diameter ~100 µm No fiber flocculation Small bubbles fill the free space There is no scientific literature related to fibrous foams

7 Foam Generation Simulations by Topi Kähärä, JyU

8 Experimental Lab Studies

9 From Water-laid to Foam-laid Process Running concepts Generation of foam Piloting On-line foam measurements Vacuum system Pumping of foam Headbox

10 VTT Foam Forming Pilots SAMPO Pilot-scale research environment for nonpressed materials Foam Forming Technology Vertical headbox Horizontal geometry Impingement and TAD dryers D=600 mm, max speed 200 m/min Start-up 2017 SUORA Pilot-scale research environment for papermaking board manufacturing processes and product development Water-laid and Foam-laid webs Stratified foam forming Small amounts of raw material <100 kg abs dry D=300 mm, max speed 2000 m/min Built 2006, rebuild 2010, foam start-up 2013

11 Aqueous cellulose-based foams Average bubble size was shown to correlate well with fiber foam stability (Salminen et al. 2014). Bubble size distribution derives to the pore structure of fiber network (Al-Quararah et al. 2015, Ketoja, ACS meeting 2016). Density of fiber foam affects fiber network strength, bulk, formation and dryness after wet pressing (Torvinen et al.2015). Flocculation tendency of fibers is proportional to rr N (Kiiskinen et al. 2016). Wate r High density foam High density foam Water Low density foam Low density foam VTT beyond the obvious

12 Strength Foam forming in the field of nonwovens Wet-laid - Strong webs - Limited fiber length - High densities 300 kg/m kg/m 3 Foam forming provides means of handling long fibers in wet conditions and to produce high porosity web Air-laid - High porosity - Limited strength Porosity

13 Compression stress (50 % compression), kpa Recovery (after 50 % compression), % Compression strength and Recovery 50% compression CTMP +SDS 85 CTMP +SDS BSKP +SDS EPS 80 BSKP +SDS EPS Density, kg/m Density, kg/m3 No strength additives Compression strength EN 826 standard (at 10% strain) CTMP (Chemithermomechanical Pulp) BSKP (Bleached Softwood Kraft Pulp) SDS (Sodium Dodecyl Sulphate)

14 Foam forming as a manufacturing platform for future fiber products Packaging and cushioning Lightweight, mouldable board Replacement for plastic Sound insulation Nonwovens Construction Growth media

15 Technology Platform for Fibre Products Towards increased value for fibre products Funding: European Regional Development Fund, participating companies and VTT Budget 4.4 M Duration 06/ / companies, coordinated by VTT Contact: harri.kiiskinen@vtt.fi erkki.hellen@vtt.fi

16 KIITOS! Phone: VTT beyond the obvious