Development of bio-composite filaments for drinking straw application

Lifestyle shifts and the pursuit of comfort have led to an increased reliance on straws for consuming beverages. This trend has contributed to the growing environmental concern related to plastic waste. Plastic straws and stirrers accounted for ~7% of the debris found in the ocean, with most being non-recyclable. This detrimental environmental impact has led to many countries banning single use plastics, which includes straws, stirrers and cutlery. The bans on single-use plastics have prompted initiatives to identify suitable alternatives, thereby creating new market opportunities for the development of biodegradable materials. This study investigates creating bio-composite material from locally available flax fibre and PLA as a filament and analyzing the properties for future manufacturing of drinking straws. Specifically, this proof-of-concept research focuses on manufacturing different bio-composite filaments and characterizing properties related to drinking straw’s functionality of strength and moisture absorption according to standardized material testing protocols. By deriving the mathematical models of these properties as a function of fibre composition, future optimization for production of value-added products will be possible. Various blends of PLA powder and flax fibre were extruded using a WellzoomTM filament extruder. Their moisture absorption, tensile properties, and flexural properties, based on ASTM D570, ASTM D638 and ASTM D790 protocols, were studied. Transfer of the rodlike filament analysis to hollow cylindrical drinking straws is possible. Moisture absorption on four specimens of each composition was completed in both distilled water and a carbonated beverage. During the initial 45 minutes, the highest rate of moisture absorption occurred ranging from 0.0006 g/min to 0.001 g/min. Minimal absorption occurred for the remaining 24hrs with distilled water, whereas the amount of absorption doubled for the carbonated beverage. The observed trends showed moisture absorption increased with increasing fibre content. No visible change in geometry or surface of the specimen occurred during the 24hrs. The tensile properties were analysed using six specimens from each composition. The filaments with 10% flax content sample exhibited superior tensile properties, and retained 63% and 82% of PLA’s tensile strength and Young’s Modulus, respectively. Samples with higher fibre content recorded lower tensile properties. Flexural properties were analysed using 5 specimens; the filaments with 7.5% fibre content had the highest flexural property and exhibited 87% of the flexural strength of PLA filament. The filament composted of 12.5% fibre (87.5P12.5F) had the lowest flexural properties. The trendline (third order polynomial) for the 8 data points had a correlation factor (R2) ranging from 0.73 to 0.9 for predicting composite material properties. By examining the manufacturing parameters and properties like water absorption, tensile and flexural, valuable insights have been gained into the behaviour and performance of these composites. Others have shown that PLA degrades at higher temperatures below PLA melting point in industrial biodigesters at rates that are in hours compared to years at temperatures near 60°C; the increase in flax fibre is expected to further increase the biodegradability. Using these results, future drinking straws may be manufactured by 3D printing or by extruding PLA-flax fibre blends. The latter requires developing an extrusion nozzle to form tubes. This could benefit many sectors, such as food and beverage, hospitality, and healthcare, which rely on straws for convenience and accessibility.

Name thesis:degree_name

Master of Applied Science (MASc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Engineering - Industrial Systems

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2023

Author dc:creator

• Annamalai Senthilnathan, Anaamalaai

Advisor dc:contributor.advisor

• Stilling, Denise

Committee member dc:contributor.committeemember

• Mehrandezh, Mehran

Language dc:language.iso

en

DOI

https://doi.org/10.82465/3881

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/16422