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1

A generic method to realize long fibers filled and large polymer parts in additive manufacturing

Hascoët Jean-Yves, Authelin Olivier, Rauch Matthieu

Journal of Machine Engineering

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2020

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Vol. 20, No. 1

107--116

EN

A general manufacturing methodology for long fibers filled and large polymer (LFFLP) parts will be proposed, which constitutes the major scientific contribution of the document. The input, output, control and analysis data at each step of the methodology will be specified. Experiments realized in the laboratory of Ecole Centrale de Nantes will demonstrate the relevance and effectiveness of this method applied to a 6-axis robot and the FFF process by showcasing two light and resistant lattice structures. The latter also highlight the capacity of 6-axis robots for orienting the deposition head in order to generate complex trajectories. Finally, perspectives and future research about this subject will be discussed such as the need to develop in-depth analyses of the manufacturing methodology. The possibility of using continuous fibres composites as material feedstock for robotized large dimensions FFF will also be covered.

2

Mechanical and electrical properties of mined coal filled polyethylene and polyamide

Rojek M., Stabik J.

Archives of Materials Science and Engineering

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2009

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Vol. 36, nr 1

34-40

EN

Purpose: The purpose of the present paper is to present results of basic mechanical properties research of high-density polyethylene and polyamide 6 filled with two kinds of mined coal particles. Because composites with carbon are expected to poses low electric resistance also surface resistivity was measured. Design/methodology/approach: Dependences of tensile strength, elongation at break, impact strength, ball hardness and surface resistivity on volume content of mined coal in polymeric matrix are measured and discussed. Findings: Introduction of mined coal fine particles to polyethylene did not cause significant changes in tensile strength, while the same property of polyamide composites decreased significantly. Brinell ball hardness of all polyethylene and polyamide composites increased almost proportionally to coal content. Pronounced lowering of deformability (elongation at break) with increasing coal content was observed for all formulations. Also impact strength significantly decreased after mined coal filling. Significant lowering of surface resistivity was noticed especially for coal-polyamide composites. Research limitations/implications: Obtained results showed that mined coal fine particles can be applied as a filler of thermoplastic polymers but poor adhesion between polymer matrix and filler particles was achieved. Additional research on mined coal fine particles modification by coupling agents is needed to develop better adhesion. Practical implications: Obtained results showed that mined coal fine particles can be applied as a filler of thermoplastic polymers but poor adhesion between polymer matrix and filler particles was achieved. Additional research on mined coal fine particles modification by coupling agents is needed to develop better adhesion. Originality/value: Polymer composites with carbon as a modifier has been used for many years but there have been only a few experiments on introducing fine particles of mined coal into thermoplastics.

3

Badania ruchu ziaren napełniaczy podczas przepływu polimerów

Stabik J.

Polimery

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2004

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T. 49, nr 10

712-718

PL

Omówiono dwa czynniki wpływające na zachowanie się ziaren napełniaczy W matrycy polimerowej podczas przepływu, mianowicie orientację w kierunku przepływu i migrację poprzeczna do tego kierunku. Odpowiednie zjawiska i zależności zbadano na przykładzie kompozycji PE-LD zawierających 2,5; 5 lub 10 % obj. napełniaczy mineralnych o ziarnach kulistych, płytkowych, igłopodobnych, włóknistych lub nieregularnych. Intensywność migracji zależy od cech geometrycznych (średnicy, powierzchni właściwej i współczynnika kształtu) ziaren jej podlegających. Opracowano modele empiryczne wiążące cechy geometryczne ziaren z intensywnością migracji. Największy wpływ na proces migracji wywiera średnica ziaren.

EN

Two factors influencing the behavior of fillers' grains in polymer matrix during the flow namely the orientation towards flow direction and migration perpendicular to this direction (Fig. 1 and 2) have been discussed. Adequate phenomena and dependences have been studied taking as examples PE-LD compositions containing 2.5, 5 or 10 vol. % of mineral fillers of spherical, lamellar, needle-shaped, fibrous or irregular grains (Table 1). Migration intensity depends on geometrical features of the grains submitted (diameter, specific surface and aspect ratio). Empirical models relating migration intensity and the grains' geometrical features have been developed [equation (8), Table 2]. Grain diameter shows the biggest effect on the migration process.