Thermo-Mechanical Behaviour of the Raffinate Resulting from the Aqueous Extraction of Sunflower whole Plant in Twin-Screw Extruder: Manufacturing of Biodegradable Agromaterials by Thermo-Pressing

Biorefinery of sunflower whole plant can be realized using a twin-screw extruder. Thermo-mechanical fractionation and aqueous extraction are conducted simultaneously. A filter section is outfitted along the barrel to collect continuously an extract and a raffinate (cake meal). Oil yield obtained is 53%. Proteins are partly extracted at the same time, just as pectins and hemicelluloses. Protein yield is 46%. Cake meal is relatively moist (66% for the moisture content). It is first dried to make easier its conservation. It is largely composed of lignocellulosic fibres (59% of the dry matter) from depithed stalk. Lipid content is 13% of the dry matter or 35% of the oil in whole plant. Protein content is 7% of the dry matter or 45% of the proteins in whole plant. DSC measurements indicate that denaturation of proteins is almost complete in the cake meal. DMTA spectrum of its milled powder reveals a significant peak at high temperature (between 175 and 200°C). As already observed with industrial sunflower cake meal, it can be associated with the glass transition of proteins. As a mixture of fibres and proteins, the cake meal can be considered as a natural composite. It is successfully processed into biodegradable and value-added agromaterials by thermo-pressing. As for DMTA analysis, the glass transition of proteins in the cake meal is also observed with PVT analysis at around 180°C. It makes easier the choice of the best thermo-pressing conditions to produce panels with higher mechanical properties in bending. These properties increase simultaneously with temperature, pressure and time chosen for molding operation. The highest flexural strength at break (11.5 MPa) and the highest elastic modulus (2.22 GPa) are obtained for the next molding conditions: 200°C and 320 kgf/cm2 during 60 s. Drop angle measurements show that the corresponding panel is also the most resistant to water. No significant transition is observed inside this panel above 0°C and until 200°C with DMTA analysis. Proteins ensure the agromaterial cohesion without any phase change in this temperature range, and fibres entanglement also acts like reinforcement. This panel could be used as inter-layer sheets for pallets or for the manufacturing of biodegradable containers (composters, crates for vegetable gardening) by assembly of panels.

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Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽

10.3390/polym13071058 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1058

Author(s):

Hikaru Okubo ◽

Haruka Kaneyasu ◽

Tetsuya Kimura ◽

Patchiya Phanthong ◽

Shigeru Yao

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Value Added ◽

Industrial Applications ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Polymer Properties ◽

Wide Range ◽

Twin Screw ◽

Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

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Direct extraction of oil from sunflower seeds by twin-screw extruder according to an aqueous extraction process: Feasibility study and influence of operating conditions

Industrial Crops and Products ◽

10.1016/j.indcrop.2007.05.001 ◽

2007 ◽

Vol 26 (3) ◽

pp. 351-359 ◽

Cited By ~ 31

Author(s):

Ph. Evon ◽

V. Vandenbossche ◽

P.Y. Pontalier ◽

L. Rigal

Keyword(s):

Feasibility Study ◽

Extraction Process ◽

Aqueous Extraction ◽

Operating Conditions ◽

Twin Screw Extruder ◽

Sunflower Seeds ◽

Screw Extruder ◽

Direct Extraction ◽

Twin Screw ◽

Aqueous Extraction Process

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New thermal insulation fiberboards from cake generated during biorefinery of sunflower whole plant in a twin-screw extruder

Industrial Crops and Products ◽

10.1016/j.indcrop.2013.10.049 ◽

2014 ◽

Vol 52 ◽

pp. 354-362 ◽

Cited By ~ 36

Author(s):

Philippe Evon ◽

Virginie Vandenbossche ◽

Pierre-Yves Pontalier ◽

Luc Rigal

Keyword(s):

Thermal Insulation ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Whole Plant ◽

Twin Screw

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Aqueous extraction of residual oil from sunflower press cake using a twin-screw extruder: Feasibility study

Industrial Crops and Products ◽

10.1016/j.indcrop.2008.09.001 ◽

2009 ◽

Vol 29 (2-3) ◽

pp. 455-465 ◽

Cited By ~ 22

Author(s):

Ph. Evon ◽

V. Vandenbossche ◽

P.Y. Pontalier ◽

L. Rigal

Keyword(s):

Feasibility Study ◽

Press Cake ◽

Aqueous Extraction ◽

Twin Screw Extruder ◽

Residual Oil ◽

Screw Extruder ◽

Twin Screw

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Restoring mechanism of mechanical properties of recycled polyethylene pellet moldings by a repelletizing treatment using a twin-screw extruder

Journal of Material Cycles and Waste Management ◽

10.1007/s10163-021-01204-9 ◽

2021 ◽

Vol 23 (3) ◽

pp. 1152-1176

Author(s):

H. Okubo ◽

S. Yao

Keyword(s):

Mechanical Properties ◽

Value Added ◽

Polymer Materials ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Material Recycling ◽

Tensile Performance ◽

Recycled Polyethylene ◽

Twin Screw ◽

Plastic Products

AbstractTo develop material-recycling processes for used plastic products, it is necessary to design new material-recycling techniques to optimize the mechanical properties of the recycled plastics since the mechanical properties of recycled plastic products are normally deteriorated. In this study, we suggest one of the approaches that is a repelletizing treatment for improving the mechanical properties of recycled-polyethylene moldings using a twin-screw extruder. The results of the tensile test revealed the significant effect of the repelletizing treatment on the tensile performance of the recycled-polyethylene moldings. The tensile performance of the repelletized recycled-polyethylene moldings was significantly higher than that of the original recycled-polyethylene moldings under specific repelletizing conditions. The analysis of the polymeric structures revealed the significant effect of the repelletizing treatment on the secondary and higher-order structures such as the lamellar shape, aggregation of the crystal domains, amorphousness, and polyethylene chain conformation in the recycled-polyethylene moldings. The repelletizing treatment increased the tensile performances by optimizing the internal structure of the recycled-polyethylene moldings. The results confirmed the efficacy of the repelletizing treatment to optimize the mechanical performance of the recycled-polymer materials, thereby facilitating the reuse of waste plastics as value-added materials for various industrial applications.

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