Development and characterisation of injection moulded, all-polypropylene composites

In this work, all-polypropylene composites (all-PP composites) were manufactured by injection moulding. Prior to injection moulding, pre-impregnated pellets were prepared by a three-step process (filament winding, compression moulding and pelletizing). A highly oriented polypropylene multifilament was used as the reinforcement material, and a random polypropylene copolymer (with ethylene) was used as the matrix material. Plaque specimens were injection moulded from the pellets with either a film gate or a fan gate. The compression moulded sheets and injection moulding plaques were characterised by shrinkage tests, static tensile tests, dynamic mechanical analysis and falling weight impact tests; the fibre distribution and fibre/matrix adhesion were analysed with light microscopy and scanning electron microscopy. The results showed that with increasing fibre content, both the yield stress and the perforation energy significantly increased. Of the two types of gates used, the fan gate caused the mechanical properties of the plaque specimens to become more homogeneous (i.e., the differences in behaviour parallel and perpendicular to the flow direction became negligible)

Development of natural fibre reinforced poly(lactic acid) biocomposites

In our work, different natural fiber reinforced PLA biocomposites were prepared by film - stacking. The effect of the fiber reinforcement and the compression molding pressure on the mechanical properties were analyzed and it was found that, the tensile and flexural strength and modulus of neat Poly(Lactic Acid) (PLA) increased by using 30wt% natural fibre reinforcement up to 80 - 90 MPa and 7 GPa respectively. The investigation of the mechanical properties of the biocomposites revealed that the pressing parameters have significant effect, due to the increased pressure and the 4 step method further improvements were reache d with a flexural strength of 110 MPa and a flexural modulus of 11,4 GPa. The best combination of the tensile and flexural properties was reached with PLA/Flax126 composites

Háromfázisú bioműanyag keverékek vizsgálata = Investigation of Three-Phase Bioplastic Blends

Napjainkban a bioműanyagok (biopolimerek) közül a politejsav (PLA – PolyLactic Acid) a legelterjedtebb, amely egy rideg polimer. Azért, hogy a PLA bioműanyag képes legyen helyettesíteni hagyományos műanyagokat, úgy mindenképpen a módosítására van szükség. Munkámban a PLA-hoz többféle bioműanyagot adtam (szívós gumiszerű, valamint rugalmas) és vizsgáltam a háromfázisú bioműanyag keverékből fröccsöntéssel előállított próbatestek tulajdonságait. Today, among the bioplastics (biopolymers), polylactic acid (PLA), which is a brittle polymer, is the most common. In order for the PLA bioplastic to be able to replace traditional plastics, it definitely needs to be modified. In my work, I added several types of bioplastics to PLA (tough rubber-like and flexible) and examined the properties of test specimens produced by injection molding from a three-phase bioplastic blend

Eltérő szerszámanyagok hatása a fröccsöntött darabok tulajdonságaira

In our work the effect of different mould material was investigated on the properties of injection moulded parts. A mould was designed and manufactured by using conventional and additive technologies. Injection moulding tests were performed using these moulds. The temperature of the moulds was determined as well as its effect on the thermal properties of the parts

Effect of different mould material on the properties of injection moulded parts = Eltérő szerszámanyagok hatása a fröccsöntött darabok tulajdonságaira

In our work the effect of different mould material was investigated on the properties of injection moulded parts. A mould was designed and manufactured by using conventional and additive technologies. Injection moulding tests were performed using these moulds. The temperature of the moulds was determined as well as its effect on the thermal properties of the parts