Durability Evaluation of an Additive Manufactured Biodegradable Composite with Continuous Natural Fiber in Various Conditions Reproducing Usage Environment

Abstract

Recently, biodegradable plastic materials that can be decomposed by living organisms have attracted significant attention because of the great demand for the safe disposal of plastics. Recycling has failed to provide a practical solution for plastic waste disposal (60% of all plastics produced are discarded). It is difficult to achieve both durability and biodegradability in biodegradable plastics. In additive manufacturing processes, polylactic acid (PLA), one of the biodegradable plastics, is typically used, but it presents strength and durability problems. We developed novel additive manufactured biodegradable composite plastics by inserting continuous natural fibers (cotton, hemp, jute, etc.) into fabricated layers of PLA. The composite had a greater strength than normal additive manufactured PLA materials and could be used like a normal PLA filament in fused deposition modeling to create free-form three-dimensional objects. In this study, we performed experiments to evaluate the durability and biodegradability of the composite (PLA as matrix and hemp fibers as reinforcement). Specimens made from the composite were exposed to a normal indoor environment and to severe environments that products might encounter during use (presence of water and UV light (300–400 nm)). The decrease in strength over time was compared with that of PLA, and the durability was evaluated. The results indicated that the strength of the manufactured composite material exceeded that of PLA under all conditions. Whereas the stiffness of PLA exposed to UV light reduced significantly, that of the composite material remained constant, suggesting the significant effect of fiber reinforcement. In addition, test specimens were buried in a simulated soil environment, and their biodegradability was evaluated. The strength of the composite material decreased rapidly, and the biodegradability was confirmed to be at an acceptable level.

Colombian Sustainability Perspective on Fused Deposition Modeling Technology: Opportunity to Develop Recycled and Biobased 3D Printing Filaments

“…The main conclusion of this study was that even though carbon fiber composites have better mechanical performance than jute composites, the latter has better mechanical resistance than the neat PLA specimens. Hemp fiber was evaluated as PLA reinforcement by Yacuchi et al [ 150 ] According to the obtained results, hemp/PLA composites exhibited an increase in tensile strength from 46.8 MPa to 65.3 MPa compared to the neat PLA matrix. Meanwhile, They identified that the composite specimens deteriorate faster than the PLA.…”

Simulated Annealing Algorithm in Nature Conservation Environment and Historical Culture

“…The SA algorithm uses an alternate process to reach a state of quasi-thermodynamic equilibrium, and its main feature is that it allows hill-climbing (i.e., movement that worsens the value of the objective function), a process that makes it partial minima at higher temperatures, thus avoiding falling into a local optimum [7]. The main components of the SA algorithm are.…”

Natural Ecological and Environmental Protection Strategies Based on Biotechnology Analysis

“…Under this condition, the displaced ball filler of the displaced biochemical pond which has been successfully cultivated with biofilm and operated stably for 1 month is taken, and the bacteria film on the surface of the displaced ball shell and the surface of the internal volcanic rock particles are scraped off a little and transferred to the anaerobic medium for cultivation for a period of time. After a period of incubation, the microorganism survival in the medium was observed by microscopic examination; the total length of the displaced biochemical pond was about 50 cm, and a number of displaced ball fillers were taken every 10 cm from the inlet, totaling 5 sections, and the microorganism species in different flow sections of the displaced biochemical pond were analyzed by microscopic examination, so as to understand the operation mechanism of the displaced ball fillers in reducing sludge volume in the wastewater treatment process [14,15].…”