Previous studies have shown favourable properties for papaya bast fibres, with a Young's modulus of up to 10 GPa and a tensile strength of up to 100 MPa. Because the fibres remain as residues on papaya plantations across the tropics in large quantities, their use in the making of green composites would seem to be worthy of consideration. This study aims to show that such composites can have very suitable mechanical properties, comparable to or even better than the common wood plastic composites (WPCs), and as such, represent a promising raw material for composites and a low-cost alternative to wood.

Previous studies have shown favourable properties for papaya bast fibres, with a Young's modulus of up to 10 GPa and a tensile strength of up to 100 MPa. Because the fibres remain as residues on papaya plantations across the tropics in large quantities, their use in the making of green composites would seem to be worthy of consideration. This study aims to show that such composites can have very suitable mechanical properties, comparable to or even better than the common wood plastic composites (WPCs), and as such, represent a promising raw material for composites and a low-cost alternative to wood.

This study has its background in the EU directive, the ‘Single-Use Plastics Directive’. The directive was initiated due to the environmental impacts that the oceans suffer due to plastic waste. The directive presents the most common single-use products found as waste in the oceans, including wipes and cloths. In collaboration with Essity, a global hygiene and health company, this study aims to find a replacement fibre for the currently used polyester fibre in Essity’s industrial cleaning cloths. To this end, we have evaluated the applicability of an agricultural fibre in the aspects of processability and sustainability. A theoretical part including a literature study of agricultural fibres is combined with a practical experimental part to evaluate a manufactured prototype. The theoretical part includes a compilation of the relevant parameters per fibre and the experimental part consists of laboratory tests and a panel test. On this basis, it was concluded that the first agricultural fibre, hemp, did not function adequately in the process due to the variations in fibre length and coarseness. A solution to this problem may be pre-treatments of the fibres. The second fibre, flax, functioned well in the process and may then be considered applicable in the aspect of process. The applicability of an agricultural fibre is possible in industrial cleaning cloths, but the geographical location of cultivation, transport, the chemicals used and irrigation should also be taken into account in the aspects of sustainability. / Bakgrunden till denna studie är EU-direktivet, ‘Single-Use Plastics Directive’. Direktivet har sitt ursprung i de miljöproblem som våra hav lider av på grund av nedskräpningen medplastavfall. Direktivet redovisar de engångsartiklar som återfinns allra mest i haven idag, däribland rengöringsdukar. På förekommen anledningen ska därför denna studie i samarbete med Essity, ett globalt hygien- och hälsoföretag, undersöka möjligheten att ersätta den befintliga polyesterfibern i deras industriella rengöringsdukar. Studien har utvärderat möjligheten att använda en naturlig fiber med avseende på tillverkningsprocess och hållbarhet. För att möjliggöra en utvärdering av en tillverkad prototyp, så har en teoretisk del med en litteraturstudie i kombination med en praktisk experimentell del genomförts. Den teoretiska delen består av en sammanställning av relevanta parametrar för varje fiber och den experimentella delen består av laboratorietester och ett paneltest. Slutsatserna från ett förstaförsök var att hampafibrer inte fungerade i processen på grund av variationer i hampansfiberlängd och grovlek. Att göra en förbehandling skulle kunna vara lösningen. I det andraförsöket med linfibrer, visade det sig att linfibrer fungerar i processen och därför kan vara applicerbar med avseende på tillverkningsprocess. En naturlig fiber kan användas i industriella rengöringsdukar, ur ett hållbarhetsperspektiv är det viktigt att beakta den geografiska platsen för odling, transporter, användning av kemikalier och konstbevattning.