Fiber Reinforced Poly Lactic Acid Research Articles

Tribology Behavior of In-Situ FDM 3D Printed Glass Fibre-Reinforced Thermoplastic Composites

Fused deposition modeling (FDM) 3D-printed parts are generally weaker compared to injection-moulded parts. Fibre reinforcement is one of the techniques used to enhance the mechanical strength and the tribological behavior of the FDM-printed parts. Recently, a new method for creating FDM 3D-printed composites was developed. Current work focuses on the tribological behavior of the glass fibre-reinforced PLA, manufactured using this new composite manufacturing method. Experiments were conducted to investigate the effect of Glass Fibre (GF) reinforcement on FDM 3D-printed thermoplastic composites, specifically polylactic acid (PLA) under different linear sliding speed and directions. All 3D printed glass fibre-reinforced PLA (PLA-GF) composites exhibited a lower wear rate and a higher friction coefficient compared to 3D printed PLA. Increasing in disc’s linear speed or sliding speed of the pins resulted in a lower coefficient of friction and wear rate. In addition, a perpendicular raster direction towards the disc rotation or pin motion experienced greater friction and greater wear.

Tailoring the vibration characteristics of carbon fiber-reinforced polylactic acid in fused filament fabrication process

The Fused Filament Fabrication (FFF) process has gained significant attention for its ability to manufacture parts using advanced polymeric materials, such as carbon fiber-reinforced polylactic acid (CF-PLA). By adjusting the printing process parameters of the CF-PLA, the optimized mechanical properties can be achieved with less chances of flaws. Structural integrity of the components plays an important role in analyzing the durability of the product which can be analyzed using modal analysis. This research study focuses on analyzing the effect of process parameters on the vibration damping characteristics of CF-PLA components produced by the FFF process. The Taguchi method is used to model the relationship between process parameters and vibration performance metrics. Based on the vibration study, the optimal process parameters were determined as 60% infill density, 0.08 mm slice thickness, and hexagonal pattern. This study shows that the natural frequency and damping increases with increase in infill percent but decreases with increase in slice thickness. The closely aligned values between the predicted and experimental results suggest that the developed model is effective in predicting the vibration characteristics of CF-PLA composites. By accurately adjusting the process parameters, the study’s findings—such as frequencies and damping ratio—provide manufacturers with important and dependable CF-PLA Fused Deposition Modeling components.

Exploring the potential of agricultural waste enset fibers reinforced poly lactic acid biocomposites

This study explores the environmental sustainability of composite materials by reinforcing agricultural residue enset fiber as a potential reinforcement. Initially, enset fibers underwent a 5 wt% sodium hydroxide treatment to eliminate impurities and enhance fiber-matrix adhesion in the subsequent biocomposite fabrication process. Various enset fiber-to-polylactic acid ratios were blended and opened to enset/PLA fibers mat using a fiber carding machine, and the resulting biocomposite material was prepared through the hot press. A comprehensive assessment covering mechanical, thermal, dynamic mechanical, water absorption, and morphological properties was conducted on the enset/PLA biocomposites. The results showed increased mechanical (tensile strength of 24.12 MPa, bending stress of 33.02 MPa, flexural modulus of 2.01 GPa, the impact resistance of 12 kJ/m2) and thermomechanical properties with increased enset fiber loading, with optimum value at a 30 % weight percentage. The Differential scanning calorimetry results showed the addition of enset fiber increases the glass transition temperatures and degree of crystallinity. SEM images confirmed robust adhesion between enset fibers and PLA. This study highlights the potential applications of enset/PLA composites in automotive, furniture, packaging, and diverse industries, emphasizing their promising role in sustainable material development.

Synergistic preparation of a straw fiber/polylactic acid composite with high toughness and strength through interfacial compatibility enhancement and elastomer toughening

Plant fiber-reinforced polylactic acid (PLA) composites are extensively utilized in eco-friendly packaging, sports equipment, and various other applications due to their environmental benefits and cost-effectiveness. However, PLA suffers from brittleness and poor toughness, which restricts its use in scenarios demanding high toughness. To expand the application range of plant fiber-reinforced PLA-based composites and enhance their poor toughness, this study employed a two-step process involving wheat straw fiber (WF) to improve the interfacial compatibility between WF and PLA. Additionally, four elastomeric materials—poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), polycaprolactone (PCL), and polyhydroxyalkanoate (PHA)—were incorporated to achieve a mutual reactive interface enhancement and elastomeric toughening. The results demonstrated that Fe3+/TsWF/PLA/PBS exhibited a tensile strength, elongation at break, and impact strength of 34.01 MPa, 14.23 %, and 16.2 kJ/m2, respectively. These values represented a 2.4 %, 86.7 %, and 119 % increase compared to the unmodified composites. Scanning electron microscopy analysis revealed no fiber exposure in the cross-section, indicating excellent interfacial compatibility. Furthermore, X-ray diffraction and differential scanning calorimetry tests confirmed improvements in the crystalline properties of the composites. This work introduces a novel approach for preparing fiber-reinforced PLA-based composites with exceptional toughness and strength.

Physical and thermomechanical characterization of unidirectional Helicteres isora fiber-reinforced polylactic acid bio-composites

Identifying novel cellulose fiber bio-composites has become a vital initiative in the exploration of sustainable materials due to increased global concern for the environment. This growing focus on eco-friendly materials has gathered significant attention in recent years. The current investigation deals with one such material, Helicteres isora reinforced Polylactic acid composites. Surface chemical treatment of fiber is one of the most effective methods to modify the hydrophilic fiber to increase its compatibility with the polymer matrix. Sodium hydroxide was used as a pre-treatment chemical to remove any impurities from the fiber surface. Pre-treated fibers were treated with Methacryl silane and Potassium permanganate solution to chemically modify the fiber surface. Density, void content and water absorption behavior of the composites were analyzed as per the standard procedure. Tensile and flexural tests were conducted to evaluate the mechanical strength, modulus, and flexibility of the unidirectional composites. Thermogravimetric and differential thermal analyses were performed to investigate the thermal stability, melting behavior and degradation profiles of prepared composites. A study of failure mechanisms and morphology of the fractured surface through photographs and SEM images revealed fiber splitting and delamination as the dominant reasons behind the failure of composites under tensile loading. Silane-treated Helicteres isora fiber-reinforced Polylactic acid composite exhibited lower water absorption and higher tensile strength than its counterparts. Untreated fiber composite showed maximum flexural strength among the tested composites. By collectively evaluating the results of the tests and properties of the composites, silane-treated fiber-reinforced Polylactic acid composites stands out as the most favorable choice.

FDM 3D printed MXene/Recycled carbon fibre reinforced polylactic acid composites: Interface optimization, toughening and enhanced electromagnetic shielding performance

Polylactic acid (PLA), a rapidly emerging bio-based plastic, faces challenges in reinforcement due to its weak mechanical properties and poor interface adhesion with carbon fibre surfaces. This study introduces an MXene/recycled carbon fibre (rCF) reinforced PLA 3D printing material, prepared through electrostatic self-assembly of MXene and recycled carbon fibre. MXene addition significantly enhances the fibre-substrate interface bonding in fibre-reinforced PLA filaments. This results in the printed parts displaying enhanced toughness, the flexural strength achieved of 105.45 MPa, modules of 5.98Gpa, and notched impact strength of 7.12 kJ/m2, realizing 15.6 %, 112.1 %, and 31.8 % improvements, respectively in comparison to pure PLA. Additionally, the modified PLA demonstrates absorption-dominated superior electromagnetic shielding performance. This research offers a viable approach for enhancing recycled carbon fibre-reinforced thermoplastic PLA and insights into designing sustainable, structurally, and functionally integrated composites.

Sustainability of Existing Phase of Extruded Fiber-Reinforced Polylactic Acid under Dynamic Shock Loading Conditions

Sustainability of Existing Phase of Extruded Fiber-Reinforced Polylactic Acid under Dynamic Shock Loading Conditions

Effect of Mechanical Fastening Versus Adhesively Bonded Joints of Polymer Composites on Lap Joint Strength

To examine the viability of combining pine needle fiber-reinforced polylactic acid composites, galvanized iron sheet and aluminum sheet via the use of mechanical fastening and adhesive bonding methods was investigated. The study included the preparation of three distinct kinds of joints, namely, adhesive, nut-bolt, and rivet joints, with the purpose of assessing their tensile and flexural strength. The findings indicated that the use of both mechanical fastening and adhesive bonding methods yielded successful outcomes in the bonding of these materials, with the strength of the joints changing based on the approach employed. The adhesive bonding approach exhibited superior tensile and flexural strength in comparison to the mechanical fastening technique. The microstructural examination demonstrated that the adhesive bonding approach yielded a consistent and uninterrupted contact between the materials, while the mechanical fastening technique exhibited some surface imperfections and deformations. The results indicated that both approaches were effective in producing robust and long-lasting joints.

Effect of Hygrothermal Conditioning on the Machining Behavior of Biocomposites

Abstract This work aims to study the cutting behavior of biocomposites under different controlled hygrothermal conditions. This investigation choice is motivated by the fact that natural plant fibers such as flax are characterized by their hydrophilicity which makes them able to absorb water from a humid environment. This absorption ability is intensified by increasing the conditioning temperature. The moisture diffusion process affects considerably the mechanical properties of the resulting composite, which causes many issues during the machining operations. In this paper, moisture diffusion, chip form, cutting and thrust forces, and scanning electron microscope (SEM) observations are considered to explore the cutting behavior of flax fiber-reinforced polylactic acid (PLA) depending on the hygrothermal conditioning time. Results reveal that moisture content in the biocomposite is significantly influenced by the conditioning temperature and the fiber orientation. Moisture content and fiber orientation affect both the curling behavior of the removed chip as well as the tool/chip interaction in terms of friction. The machinability of flax fiber-reinforced PLA biocomposites depending on hygrothermal conditioning time is then investigated using SEM analysis in addition to analytical modeling. An analysis of variance is used finally to quantify the observed results.

A study of the mechanical, thermal and rheological properties of sisal fiber-reinforced polylactic acid bio-composites with tributyl 2-acetylcitrate as a plasticizer

In this study, bio-composites were developed using polylactic acid (PLA) as the matrix and sisal fibers (SFs) derived from agave sisalana leaves as the reinforcement. The bio-composites were prepared through injection molding with the addition of tributyl 2-acetylcitrate (ATBC) plasticizer. The mechanical, thermal, and rheological properties of these bio-composites were investigated to understand the effects of fiber and plasticizer contents. The results showed that the addition of SFs improved the tensile and flexural moduli of the bio-composites but led to a decrease in tensile strength compared to neat PLA. The flexural strength initially decreased with low fiber content but recovered to the level of neat PLA as the fiber content increased. The impact strength increased with the incorporation of SFs and ATBC. However, the presence of ATBC had a negative impact on the tensile and flexural properties of the bio-composites. The thermal conductivity of the materials was influenced by the fiber content and processing temperature, increasing with SFs inclusion but decreasing with temperature. Differential scanning calorimetry analysis revealed increased crystallinity of PLA with the presence of SFs and ATBC. The specific heat capacity increased with ATBC but decreased with increasing SFs. Dynamic mechanical property testing showed variations in storage and loss moduli of the bio-composites at different temperatures. The storage modulus increased with higher fiber content and abruptly dropped around glass transition temperature. Rheological characterization demonstrated effective interactions between the fibers and matrix with good fiber dispersion, resulting in uniform shear viscosity versus shear rate for different capillary dimensions. The shear viscosity of the SFs/PLA mixture increased with increasing fiber content but decreased with the addition of plasticizer. Furthermore, the compounding and molding processes had a notable impact on the microstructure of the fibers, specifically resulting in fiber breakage and fiber separation during processing.

Determination of shear strength of additively manufactured poly lactic acid/flax fibre bio-composite via the iosipescu test

The need to reduce CO2 emissions is leading to the search for alternatives to the manufacture of products from petrochemical sources. One of these alternatives is polylactic acid a bio-sourced, and biodegradable material, which is expected to be one of the most widely used materials in the forthcoming years. Recently, the feasibility of enhancing the mechanical characteristics of the PLA, by adding the flax fibre was demonstrated. Flax fibers are becoming an ideal alternative in reinforced polymer composites, thanks to the energy-intensive processing required to elaborate synthetic fibers. Flax fibers are not only recyclable and bio-degradable but also have excellent mechanical characteristics. However, the mechanical properties of flax fibre-reinforced polylactic acid composites, obtained by additive manufacturing techniques, are not well known. In the first part of this study, the quality of the Iosipescu shear experiment is examined with full-field strain measurements. In the second part, the in-plane shear response of manufactured flax fibre reinforced polylactic acid composites notched with the machining process and additive manufacturing technique are compared. This last makes it possible to evaluate the influence of the printing conditions and in particular the shell layers (contour) on the mechanical characteristics. It was perceived that the fully 3D printed specimens had a greater shear strength (+50.47%) and shear modulus (+44.68 %) than machined notch specimens. The fully 3D printed specimens count with the presence of a contour that rounds the vertices of the notches, reducing the stress-concentration factor, whereas in machined notch specimens, such contour was removed.

A correlation study on piezo-embedded carbon fibre reinforced polylactic acid composite: Experimental and numerical modelling

In this research work, a piezoelectric sensor and actuator model was designed. Carbon fibre-reinforced polylactic acid (CF/PLA) composites were fabricated using the fused deposition modelling (FDM) technique using many parameters to achieve this goal. For instance, the primary key parameters were 0.1 mm (layer height) and 25 mm/s (print head). Besides, the fabricated samples were subjected to a tensile study. Besides, MATLAB® Partial Differential Equation (PDE) tool was used to develop a finite element analysis (FEA) model for the piezoelectric actuator using the experimentally tested results. The MATLAB® was also used to examine the geometry and tip deflection. The experimental works were carried out to measure the sample’s strain using piezoelectric sensors. This approach could be used to establish the accuracy of the model. The CF/PLA composites were fabricated using 20 wt.% of reinforcements. The experimental results and finite element simulation were good agreement on results. Results reported that the deflections of 6.5765 mm, 5.197 mm, and 7.6328 mm, respectively embedded with PZT 5J, PZT 5H, and PZT 5A.

Development of fiber-reinforced polylactic acid filaments using untreated/silane-treated trichosanthes cucumerina fibers for additive manufacturing

Multi-material additive manufacturing is gaining importance due to the enhancement of properties by utilizing different materials in a single additive process, especially in 3D printing. The prime motive is the need for eco-friendly materials, with the waste-to-wealth concept being the current global trend. Trichosanthes Cucumerina stem fiber, which is obtained from the discarded stem of Trichosanthes Cucumerina plant, is used in this work; the treatment of the Trichosanthes Cucumerina fibers was done using silane. Six filaments were developed with varying untreated/silane-treated Trichosanthes Cucumerina contents (3, 6, and 9%) compared with pure PLA filaments for 3D printing. Developed filaments were assessed for ultimate tensile strength, diameter variation, differential scanning calorimetry, water absorption, morphological and surface roughness. The test results elucidated that the 6% silane-treated Trichosanthes Cucumerina fiber-reinforced/PLA filament had the highest tensile strength of 63.5 MPa with better fiber distribution. The 3% silane-treated Trichosanthes Cucumerina fiber-reinforced/PLA filament had the least diameter deviation of 0.0015 mm. Based on the test data, the 6% silane-treated Trichosanthes Cucumerina fiber-reinforced/PLA filament can be utilized to prepare biodegradable components.

Mechanical performances of printed carbon fiber-reinforced PLA and PETG composites

In this study, the 3D printing technology was adopted to produce carbon fiber-reinforced polylactic acid and polyethylene terephthalate glycol composites. Fused deposition modeling process was conducted at different settings of printing parameters, specifically, raster angle, printing speed, and extrusion temperature. Each of the selected printing parameters has a key role in making the best-printed part in terms of layer-by-layer deposition quality and mechanical performance. To examine how these process parameters affect the behavior of the printed parts, tensile tests were performed and mechanical properties were assessed. It was reported that the printing orientation, characterized by the raster angle, can be identified as the determining factor to define the fracture mode. Composite parts printed with 0° raster angle, aligning with the tensile loading path, exhibit the highest levels of stiffness and ductility. Ductile and brittle fractures corresponding to 0° and 90° raster angles, respectively, were illustrated through optical observations of failure profiles. Furthermore, the tensile test indicates that higher printing speed leads to a significant deterioration in mechanical performances, notably reducing the stiffness of the printed structures. Scanning electron microscopy analysis confirmed that increasing the printing speed results in greater porosity within the structure, thereby weakening its mechanical strength. Regarding the extrusion temperature, it was shown that elevating it enhances the mechanical characteristics of the printed parts, particularly in terms of strength and ductility. Referring to microstructural observations, this outcome is attributed to the improved adhesion between the deposited layers and the reduction in porosity at high extrusion temperature.

Fabrication and Performance of Continuous 316 Stainless Steel Fibre-Reinforced 3D-Printed PLA Composites.

This study investigates the feasibility of 3D printing continuous stainless steel fibre-reinforced polymer composites. The printing study was carried out using 316L stainless steel fibre (SSF) bundles with an approximate diameter of 0.15 mm. This bundle was composed of 90 fibres with a 14 μm diameter. This fibre bundle was first coated with polylactic acid (PLA) in order to produce a polymer-coated continuous stainless steel filament, with diameters tailored in the range from 0.5 to 0.9 mm. These filaments were then used to print composite parts using the material extrusion (MEX) technique. The SSF's volume fraction (Vf) was controlled in the printed composite structures in the range from 4 to 30 Vf%. This was facilitated by incorporating a novel polymer pressure vent into the printer nozzle, which allowed the removal of excess polymer. This thus enabled the control of the metal fibre content within the printed composites as the print layer height was varied in the range from 0.22 to 0.48 mm. It was demonstrated that a lower layer height yielded a more homogeneous distribution of steel fibres within the PLA polymer matrix. The PLA-SSF composites were assessed to evaluate their mechanical performance, volume fraction, morphology and porosity. Composite porosities in the range of 2-21% were obtained. Mechanical testing demonstrated that the stainless steel composites exhibited a twofold increase in interlaminar shear strength (ILSS) and a fourfold increase in its tensile strength compared with the PLA-only polymer prints. When comparing the 4 and 30 Vf% composites, the latter exhibited a significant increase in both the tensile strength and modulus. The ILSS values obtained for the steel composites were up to 28.5 MPa, which is significantly higher than the approximately 13.8 MPa reported for glass fibre-reinforced PLA composites.

Design and Optimization of 4D Printed Carbon Fiber Reinforced Poly Lactic Acid Parts Using Fused Deposition Modeling for Shape Memory Applications: A Taguchi Approach

The manufacturing industry has witnessed substantial interest in the advancement of 4D printing technology in recent years. This technology has enabled the production of complex structures with enhanced functionality and adaptability. Fused Deposition Modeling (FDM) has become a preferred technique for 4D printing due to its ease of use, affordability, and versatile nature. To achieve efficient and effective 4D printing, the process parameters must be optimised to ensure the desired shape recovery behaviour of the printed parts. The main objective of this study is to optimize the process parameters for the production of 4D printed components using FDM technology and Carbon Fiber reinforced Poly Lactic Acid (CF/PLA) Shape Memory Polymer Composites (SMPCs). This study examines the shape recovery properties of the printed components by modifying the process parameters, including Infill Density (ID), Geometrical Thickness (GT), and Bending Angle (BA), through the implementation of Design of Experiments (DOE) L9 Orthogonal Array (OA). Utilizing Analysis of Variance (ANOVA) to determine the significant factors and their optimum levels, the process parameters are statistically analysed. The results indicate that ID and GT are the statistically significant parameters, and the optimum levels for parameters includes 20% ID, 1.5mm GT, and 300 BA led to faster shape recovery. This study demonstrates the effectiveness of the Taguchi approach in the design and optimization of the process parameters for 4D printed parts using FDM.

Sound absorption and transmission loss of 3D printed wood fibre reinforced poly lactic acid with functionally graded perforations

ABSTRACT The effect of wood fibre reinforcement on acoustic properties of 3D printed poly lactic acid samples having varying cross-section perforation and functionally graded spherical perforations is presented. Acoustic characteristics like sound absorption as well as transmission loss are obtained using an impedance tube setup. Results revealed the benefits due to the addition of wood fibres in PLA improved samples’ sound transmission loss characteristics significantly. The sound absorption curve peaks shifted to low-frequency regions which are favourable to living beings. The material can be used in acoustic insulation for structural and transportation applications, especially where eco-friendliness and aesthetics are of major concern.

Enhanced Dynamic Impact Resistance of 3D-Printed Continuous Optical Fiber-Reinforced Helicoidal Polylactic Acid Composites.

Characterized by light weight and high strength, composites are widely used as protective materials in dynamic impact loading under extreme conditions, such as high strain rates. Therefore, based on the excellent tensile properties of continuous fiber and the good flexibility and toughness of the bionic spiral structure, this study uses a multi-material 3D printer to incorporate continuous fiber, and then modifies the G-CODE file to control the printing path to achieve the production of a continuous fiber-reinforced Polylactic Acid composite helicoidal (spiral angle 60°) structure (COF-HP). Dynamic behavior under high-strain-rate impact experiments have been conducted using the Split Hopkinson Pressure Bar (SHPB). Stress-strain curves, impact energy curves and high-speed camera photographs with different strain rates at 680 s-1 and 890 s-1 have been analyzed to explore the dynamic process and illustrate the damage evolution. In addition, some detailed simulation models considering the incorporation of continuous optical fiber (COF) and different strain rates have been established and verified for deeper investigations. The results show that the COF does enhance the impact resistance of the laminates. When the porosity is reduced, the maximum stress of the continuous fiber-reinforced composite material is 4~7% higher than that of the pure PLA material. Our findings here expand the application of COF and provide a new method for designing protective materials, which have broad application prospects in the aerospace and automotive industries.

The flexural and compressive properties of sandwich composites with different 3D-printed core structures

In this study, different core structures are produced with polylactic acid (PLA) and carbon fiber reinforced PLA (CFR-PLA) filaments using a 3D printer with fused deposition modeling (FDM) technique. An alternative new core structure is proposed to the honeycomb and square core structures commonly used in the literature. Then, sandwich composites are produced by bonding carbon fiber-epoxy plates to the lower and upper surfaces of these core structures. The effect of carbon fiber reinforcement and core types on the mechanical properties of sandwich composites was investigated. The core structures produced with carbon fiber-reinforced PLA showed lower compressive strength but higher compressive modulus than those produced with pure PLA. Among the core structures, the designed structure showed the highest compressive strength with a value of 9.867 MPa, which is 32.18% and 54.36% higher than the honeycomb and square structure. While the flexural strength and flexural stiffness of the sandwich composites increased with carbon fiber reinforcement, the designed sandwich composite showed approximately 1.40 and 3.15 times the flexural strength of the honeycomb and square sandwich composites, respectively.

Experimental investigation on fatigue life and tensile strength of carbon fiber-reinforced PLA composites based on fused deposition modeling

Fused deposition modeling (FDM) is a widely used additive manufacturing (AM) method that offers great flexibility in fabricating complex geometries without requiring expensive equipment. However, compared to other manufacturing methods, FDM-produced parts generally exhibit lower strength and fatigue life. To overcome this limitation, researchers have explored the use of fibers and reinforcements to enhance the mechanical properties of FDM parts. Nevertheless, the performance of FDM-produced parts can be significantly affected by various manufacturing parameters, including infill density, which is a key factor in balancing time and cost. In this study, the tensile strength and fatigue life of carbon fiber-reinforced polylactic acid (PLA) composites produced by FDM were investigated by varying the infill density (50 and 75%) and raster angle (0°, 45°, and 90°). The effects of 100% filling density, raster width, and nozzle diameter on mechanical properties were also examined. The experimental results demonstrated that increasing the infill density and decreasing the raster angle can enhance the tensile strength, although the fatigue behavior was found to be more complex and dependent on the infill density. The optimal parameters for producing FDM parts with improved mechanical properties were identified based on the analysis of the tensile strength and fatigue life data. This research has yielded significant findings concerning the diverse fatigue behavior associated with the raster angle at different infill densities. Specifically, noteworthy observations reveal that a raster angle of 45 degrees at 50% infill density, and a raster angle of 0 degrees at 75% infill density, exhibited the most prolonged fatigue life. This outcome can be ascribed to the specific loading conditions and the inherent strength of the sediment layer at the critical point of stress concentration.