Higher Fiber Loading Research Articles

Feasibility of incorporating leaf date palm fibers in geopolymer composites made from mining waste

This study explores the potential of developing novel high performance geopolymer composite (GPC) materials utilizing mining waste (MW) as an aluminosilicate precursor for the geopolymer matrix and reinforcing it with leaf date palm fibers (LDPFs). Specifically, we examined the effects of incorporating varying amounts of LDPF fibers on the mechanical, physical, and morphological properties of the formulated GPC. The explored range of the incorporated fibers was from 0% to 4% (wt/wt). Mechanical properties were evaluated using modulus of rupture (MOR) and modulus of elasticity (MOE), while physical properties were assessed through water absorption (WA) and thickness swelling (TS). Additionally, X-ray diffraction (XRD), FTIR spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) were employed to visualize matrix phases and analyze the composition, elucidate changes in the structure, and examine the interfacial failure morphology, respectively. The results revealed that the MOR and MOE nearly doubled in the formulation reinforced with 2% (wt/wt) LDPF fibers compared to the geopolymer matrix, confirming the efficacy of these fibers as reinforcing element enhancing the strength and stiffness of the geopolymer matrix. The physical properties exhibited an increase with higher fiber loading, though they remained lower compared to those of other composites found in literature, confirming the suitability of LDPF fibers for geopolymer composite formulations. The structural and morphological analyses of the geopolymer composites indicated an acceptable degree of geopolymerisation and the fibers displayed good interfacial bonding with the geopolymer matrix, respectively. The research findings suggest that leaf date palm fibers are well-suited for reinforcing geopolymer matrix derived from mining waste, presenting a cost-effective option for construction materials.

Mechanical and Thermal Analysis of Nito Fiber Reinforced Composites

Fiber optimization is one of the key factors in fabricating fiber-reinforced composites. A higher amount of fiber loading does not correspond to improved mechanical and thermal properties of composites. Consequences such as poor fiber wetting, formation of voids, and delamination may arise due to the lower amount of matrix at higher fiber loading. In this study, the loading percentage of nito fibers were varied from 5, 10, and 15 wt%. The mechanical and thermal analysis showed that the composite with the lowest fiber loading percentage showed a better performance compared to the two composites with higher fiber loading. The tensile strength of the said composite increased by 3 MPa while the onset of degradation temperature increased by 30.91°C. The SEM micrographs confirmed that the composites with higher fiber loading percentage suffered poor wettability which resulted in poor adhesion of the fiber to the matrix. The micrographs of the composite with 5 wt% showed a superb fiber-matrix bonding which resulted in a more seamless transfer of heat and stress upon heat and load application. These results proved that optimization of fiber loading percentage is an integral step to fabricate an improved composite material.

Effect of fibre loading on mechanical properties of jute fibre bundle reinforced gypsum composites

Gypsum plasterboards are widely used in interior decoration like false ceilings, wall partitioning etc. The main component of this plasterboard is gypsum, which is a mineral material. These boards contain poor mechanical strength with lower durability. The addition of natural fibres in these plasterboards can be useful to achieve better mechanical properties. Since Jute fibre is abundant in Bangladesh and its usability in reinforced composites is well established, for this reason, jute fibre was selected to do the research. The aim of this study was to evaluate the impact of jute fibre on the mechanical properties of the gypsum plasterboard. To make this board, Plaster of Paris and water were thoroughly mixed to make a suspension first. Different fibre loadings of 2, 4, 6, and 8% were incorporated into gypsum composites. Reinforcement of 6% fibre provided the highest tensile properties, but 8% fibre loading showed inferior tensile and flexural properties. Impact test results showed a gradually improving nature with fibre loading, and hardness values showed a decreasing trend in hardness with higher fibre loading. FTIR results and SEM images confirmed that no significant chemical bonding took place in the composites, instead, the composite depended mainly on the mechanical bonding among the reins crystals and between the fibre and gypsum matrix.

Evaluation of tensile strength of cattle horn reinforced RLDPE composite

ABSTRACT Investigating novel natural fiber (NF) in developing and producing advanced composite materials (ACMs) is becoming most recent research domain among the material’s scientists and engineers. This occurred as a result of serious and unavoidable request to switch over from synthetic fibers which are non-renewable, decomposable and recyclable at their end of life and likewise costly. Treated cattle horn fiber (TCHF) was employed in this study to reinforce water sachet plastic waste using compounding and compression method. The disposed water sachet plastics acted as the source of recycled low density polyethylene (RLDPE) used in the research. Likewise, the cattle horns were picked randomly, cleaned and machined into fibers with the lengths of 6mm, 12mm and 18mm and then modified with 0.1, 0.2 and 0.3 Normality of NaOH. Moreover, the proportions of matrix materials (RLDPE) were varied by 10% interval ranging from 70% to 90% and fiber loading from 10-30%. L-9 Taguchi array method was used to design and analyses the results in order to find the best combination of fiber length, fiber and matrix volume fraction, and proportion of NaOH that would give the optimum tensile strength. The result revealed that Sample with 0.1N, 6mm fiber length (CHFL) and 10% fiber loading (CHFV) has maximum tensile strength. This means that tensile property of cattle horn reinforced RLDPE did not depend on the higher fiber loading. Also NaOH contributed highest percent of 47.08% to the tensile strength while CHFV contributed 11.71% but tensile strength decreases with increment in fiber length. Keywords: cattle horn fiber; composite; plastic; recycling; and tensile strength

Effect of Water Absorption on the Mechanical Properties of Wheat Straw Fibre Reinforced Polystyrene Composites

The present work deals with the effect of water absorption on the mechanical properties of alkali plus silane treated wheat straw reinforced polystyrene composites. Wheat straw polystyrene composite was prepared with different fibre loading (5%, 10%, 15%, 20%, 25%) by compounding process using twin screw extruder. Samples were prepared by the compression moulding process. There was a decrease in the tensile strength initially at 5% fibre loading followed by an increase in it with higher fibre loading. There is an increase in flexural strength up to 15% fibre loading followed by decrease in it with higher fibre loading. There is an increase in the hardness initially at 5% fibre loading followed by decrease in it with higher fibre loading. There is an increase in water absorption with percentage increase in fibre loading. Tensile strength, flexural strength, and hardness of alkali plus silane treated wheat straw reinforced polystyrene composites with water absorption is always less than alkali plus silane treated wheat straw reinforced polystyrene composites without water absorption.

Oxidative delignification: The roles of lignin reactivity and accessibility

This study compared oxidative delignification of birch kraft pulp fibers to pulp fibers from acid hydrotropic fractionation (AHF) using p-toluenesulfonic acid (p-TsOH). Under oxygen delignification at 20% consistency, AHF pulps with lower hemicellulose content showed higher delignification than kraft pulps with similar lignin content despite its residual lignin (cellulosic enzymatic lignin, CEL) being less reactive with fewer β-O-4 ether aryl linkages based on 2D13C-1H nuclear magnetic resonance (NMR) spectroscopy. The water retention value (WRV) of AHF pulp fibers, a measure of fiber accessibility to water or oxidative chemicals, was substantially greater than that of kraft pulp fibers. Similar comparison of various AHF pulps further suggested that fibers with lower hemicellulose content were easier to delignify (bleach) despite having more lignin with lower reactivity (fewer β-O-4 linkages). Additionally, the present study also indicated that oxygen delignification was more effective at high fiber consistency, which can be attributed to thinner water films on the fiber surfaces at higher fiber loadings. These results indicated that mass transfer was the rate controlling process in oxidative delignification of wood fibers.

Continuous Fiber-Reinforced Aramid/PETG 3D-Printed Composites with High Fiber Loading through Fused Filament Fabrication

Recent development in the field of additive manufacturing, also known as three-dimensional (3D) printing, has allowed for the incorporation of continuous fiber reinforcement into 3D-printed polymer parts. These fiber reinforcements allow for the improvement of the mechanical properties, but compared to traditionally produced composite materials, the fiber volume fraction often remains low. This study aims to evaluate the in-nozzle impregnation of continuous aramid fiber reinforcement with glycol-modified polyethylene terephthalate (PETG) using a modified, low-cost, tabletop 3D printer. We analyze how dimensional printing parameters such as layer height and line width affect the fiber volume fraction and fiber dispersion in printed composites. By varying these parameters, unidirectional specimens are printed that have an inner structure going from an array-like to a continuous layered-like structure with fiber loading between 20 and 45 vol%. The inner structure was analyzed by optical microscopy and Computed Tomography (µCT), achieving new insights into the structural composition of printed composites. The printed composites show good fiber alignment and the tensile modulus in the fiber direction increased from 2.2 GPa (non-reinforced) to 33 GPa (45 vol%), while the flexural modulus in the fiber direction increased from 1.6 GPa (non-reinforced) to 27 GPa (45 vol%). The continuous 3D reinforced specimens have quality and properties in the range of traditional composite materials produced by hand lay-up techniques, far exceeding the performance of typical bulk 3D-printed polymers. Hence, this technique has potential for the low-cost additive manufacturing of small, intricate parts with substantial mechanical performance, or parts of which only a small number is needed.

Electrical Conductivity Modeling of Polymer Composite Bipolar Plates

Polymer composites offer the potential for manufacturing lightweight, low-cost, fuel cell bipolar plates [1]. In this work, we develop a micromechanical model to predict the electrical conductivity of these composites. Using the Fiber Contact Model, conductivity was predicted based upon direction in the material, fiber alignment, fiber length and diameter, fiber concentration, and fiber conductivity [2]. Fiber alignment was determined experimentally by imaging cross sections of injection-molded nylon/carbon fiber composites. In addition to modeling electrical properties, the Halpin-Tsai equations are used to model the elastic modulus and ultimate strain of the composite. Conductivity and elastic modulus are predicted to increase in the injection direction of the composite with higher fiber loadings as well as with improved alignment of the fibers [3]. Development of an objective function for optimizing cost, ultimate strain, and conductivity, leads to optimal fiber volume fractions in the longitudinal and transverse directions of the composite.In addition to modeling efforts, electrical conductivity measurements were also performed on injection-molded nylon/carbon fiber composites. Modeling predictions are compared to experimental conductivity data for nylon composites with carbon fiber loadings of 10, 20, 30, and 40 wt%. The analytical predictions show good correlation within 10% of the experimental results. For 20, 30, and 40 wt% samples, conductivities were above the United States DOE technical target for bipolar plate conductivity (> 100 S/cm), reaching 250 S/cm. While higher carbon fiber loadings would further increase conductivity, beyond 50 wt%, the increased viscosity of the polymer blends can inhibit proper injection molding. Mighri, F.; Huneault, M. A.; Champagne, M. F., Electrically conductive thermoplastic blends for injection and compression molding of bipolar plates in the fuel cell application. Polymer Engineering and Science 2004, 44 (9), 1755-1765.Weber, M.; Kamal, M. R., Estimation of the volume resistivity of electrically conductive composites. Polymer Composites 1997, 18 (6), 711-725.Zameroski, R.; Kypta, C. J.; Young, B. A.; Sanei, S. H. R.; Hollinger, A. S., Mechanical and Electrical Properties of Injection-Molded MWCNT-Reinforced Polyamide 66 Hybrid Composites. Journal of Composites Science 2020, 4 (4), 14. Figure 1

Investigation of Fibre Orientation and Void Content in Bagasse Fibre Composites Using an Image Analysis Technique

In this research work, a nondestructive technique of image analysis was explored to determine the fibre orientation and void content in Bagasse fibre reinforced composites. Fibre length, alkali treatment and fibre loading were studied as variables. The fibre orientation was irrespective of the fibre length, fibre loading and alkali treatment variables. The void content and size decreased with increases in fibre length and alkali treatment. The alkali treatment resulted in the removal of lignin, making the surface of the fibres rough. It also led to making the fibre count fine i.e. reducing the diameter of the fibres and thus presenting more fibres for interaction with resin. Both these phenomena resulted in a slower flow of resin. The void content of bagasse fibre composites decreased with higher fibre loading because a higher number of fibres slows the resin flow. However, the size i.e. area of the voids increased with the fibre loading from 20 to 30%, probably due to increased wetting difficulty.

Study on Temperature-Dependent Properties and Fire Resistance of Metakaolin-Based Geopolymer Foams.

This paper presents temperature-dependent properties and fire resistance of geopolymer foams made of ground basalt fibers, aluminum foaming agents, and potassium-activated metakaolin-based geopolymers. Temperature-dependent properties of basalt-reinforced geopolymer foams (BGFs) were investigated by a series of measurements, including apparent density, water absorption, mass loss, drying shrinkage, compressive and flexural strengths, XRD, and SEM. Results showed that the apparent density and drying shrinkage of the BGFs increase with increasing the treated temperature from 400 to 1200 °C. Below 600 °C the mass loss is enhanced while the water absorption is reduced and they both vary slightly between 600 and 1000 °C. Above 1000 °C the mass loss is decreased rapidly, whereas the water absorption is increased. The compressive and flexural strengths of the BGFs with high fiber content are improved significantly at temperatures over 600 °C and achieved the maximum at 1200 °C. The BGF with high fiber loading at 1200 °C exhibited a substantial increase in compressive strength by 108% and flexural strength by 116% compared to that at room temperature. The enhancement in the BGF strengths at high temperatures is attributed to the development of crystalline phases and structural densification. Therefore, the BGFs with high fiber loading have extraordinary mechanical stability at high temperatures. The fire resistance of wood and steel plates has been considerably improved after coating a BGF layer on their surface. The coated BGF remained its structural integrity without any considerable macroscopic damage after fire resistance test. The longest fire-resistant times for the wood and steel plates were 99 and 134 min, respectively. In general, the BGFs with excellent fire resistance have great potential for fire protection applications.

Characterization Study of Empty Fruit Bunch (EFB) Fibers Reinforcement in Poly(Butylene) Succinate (PBS)/Starch/Glycerol Composite Sheet.

In this study, a mixture of thermoplastic polybutylene succinate (PBS), tapioca starch, glycerol and empty fruit bunch fiber was prepared by a melt compounding method using an industrial extruder. Generally, insertion of starch/glycerol has provided better strength performance, but worse thermal and water uptake to all specimens. The effect of fiber loading on mechanical, morphological, thermal and physical properties was studied in focus. Low interfacial bonding between fiber and matrix revealed a poor mechanical performance. However, higher fiber loadings have improved the strength values. This is because fibers regulate good load transfer mechanisms, as confirmed from SEM micrographs. Tensile and flexural strengths have increased 6.0% and 12.2%, respectively, for 20 wt% empty fruit bunch (EFB) fiber reinforcements. There was a slightly higher mass loss for early stage thermal decomposition, whereas regardless of EFB contents, insignificant changes on decomposition temperature were recorded. A higher lignin constituent in the composite (for high natural fiber volume) resulted in a higher mass residue, which would turn into char at high temperature. This observation indirectly proves the dimensional integrity of the composite. However, as expected, with higher EFB fiber contents in the composite, higher values in both the moisture uptake and moisture loss analyses were found. The hydroxyl groups in the EFB absorbed water moisture through formation of hydrogen bonding.

3D Printing of Carbon Fiber Composite: The Future of Composite Industry?

Fabricating composite parts with high fiber loading and design flexibility has always been a challenge. In the recent issue of Matter, Shi and co-workers showed that high fiber loading can be achieved using localized in-plane thermal assisted (LITA) 3D printing. Coupled with robotic arm, it provides a promising way to fabricate lightweight and high-performance continuous fiber reinforced thermoset composites with great design flexibility. Is 3D Printing of carbon fiber composite the inevitable revolution for the composite industry? We discuss the challenges and potentials briefly here toward the future of composite manufacturing.

Enhancing Mechanical Performance of Bagasse Fiber-Epoxy Composite by Surface Treatment

Surface treatment is one of the method used to enhance the mechanical performance of natural fiber composite by improving the compatibility of fiber and matrix. Nevertheless, no proof can be shown on which surface treatment is the absolute solution in improving the mechanical properties of natural fiber composite. Different surface treatments might have needed for different kinds of natural fiber composites. In this research work, water, alkaline, permanganate, bleaching and acetylation treatment on bagasse fiber are evaluated and the effect of soaking temperature as well as the effect of fiber loading are investigated. The mechanical performance of bagasse fiber-epoxy composite was studied by carrying out three-point bending test and optical microscopy test. Among 0w/w% and 5w/w% fiber loading, composite with 1w/w% and 2w/w% fiber loading possessed the highest flexural strength and modulus respectively. However, poor wettability between fiber and matrix was observed at higher fiber loading. Water, bleaching, permanganate and acetylation treatment have minor positive effect on the mechanical performance of the composite, yet a great increment in flexural properties of alkali treated fiber composite was noticed such that 21.48% and 23.95% of improvement was made on flexural strength and flexural modulus respectively. Optical microscopy test indicated that alkali treatment is responsible for roughening the fiber surface, and improving the fiber wettability and dispersion. Depend on the surface treatment, effect of soaking temperature may vary. In some treatments, hotter soaking temperature led to faster rate of reaction, which resulted in greater surface roughening and greater cleansing effect. Despite of that, over reaction can be happened in some cases, which will result in lower flexural properties due to over damaged fiber. Hence, it was concluded that the alkaline treatment at room temperature could be the most effective surface treatment to enhance the mechanical performance of bagasse fiber-epoxy composite.

Improving the oil sorption capability of porous polyurethane composites by the incorporation of cellulose fibers extracted from water hyacinth

Cellulose fibers were successfully extracted from water hyacinth (Eichhornia crassipes) and incorporated into porous polyurethane composites at fiber loadings of 1–7 wt%. As expected, the polyurethane composites became more hydrophilic as the cellulose loading was increased. The porosity of the composite structure was also affected by the addition of fiber. Composites with higher fiber loadings had greater macropore volumes. Preliminary investigation of oil sorption was conducted, and the addition of water hyacinth-derived fiber was demonstrated to significantly improve oil sorption by the porous composites. This was attributed to the greater porosity of composites with higher fiber loadings.

Study on flexural performance of fabricated natural fiber hybrid polypropylene composite: an experimental investigation through designed experiments

PurposeThis paper aims to investigate the flexural properties i.e. the flexural strength and the flexural modulus under the influence of selected input variables, namely; fiber type, fiber loading and fiber size in fabricated natural fiber polymeric composites through using Taguchi’s design of experiment methodology.Design/methodology/approachThe Taguchi’s design of experiment approach has been used to scheme a suitable combination to fabricate the polymeric composites. Pure polypropylene (PP) has been chosen as a matrix material, whereas two types of fibers, namely; wood powder (WP) i.e. sawdust and rice husk powder (RHP), have been used as a reinforcement in the matrix. Microstructure analysis of fabricated and tested samples has also been evaluated and analyzed using a scanning electron microscope. This analysis has divulged that at moderate fiber size and higher fiber loading, no gap or cavities presented between the fillers and matrix particles, which illustrates the good interfacial bonding between the materials.FindingsThe flexural strength of the wood powder pure polypropylene (WPPP) composite decreases if the fiber content gets increased beyond 20 Wt.%. In addition, the flexural strength of hybrid composite (WPRHPPP) has been revealed to get improved more in comparison to composites with single fiber as reinforcement. Furthermore, the flexural modulus of WPPP composite has also increased with the increase in fiber loading. It has been concluded that reinforcement size plays an imperative role in influencing the flexural modulus. The optimum parametric setting for the flexural strength and the flexural modulus has been devised as; fiber type – WPRHP, fiber loading – 10 Wt.% and fiber size – 600 µm; and fiber type – WP, fiber loading – 30 Wt.% and fiber size – 1,180 µm, respectively. The microstructure images clearly revealed that during conducted flexural tests, some particles get disturbed from their bonded position that mainly represents the plastic deformation.Social implicationsThe fabricated polymer materials proposed in the research work are green and environmentally friendly.Originality/valueThe natural fiber-based composites are possessing wide-spread requirements in today’s competitive structure of manufacturing and industrial applications. The fabrication of the natural fiber-based composites has also been planned through the designed experiments (namely; Taguchi Methodology- L9 orthogonal array matrix), which, further, makes the analysis more fruitful and qualitative too. The fabricated polymer materials proposed in the research work are green and environmentally friendly. Shisham WP has been rarely used in the past researches; therefore, this factor has been included for the present work. The injection molding process is used to fabricate the three different polymer composite by varying the fiber weight percentage and fiber size.

Extrusion processing of a high fibre loading of agrowaste in recycled polyolefin biocomposite

A high loading rice husk fibre (RHF) incorporated polyolefin blend of recycled polyethylene high-density/poly(ethylene terephthalate) (rPEHD/rPET) biocomposite was produced through extrusion and hot/cold press process. Interfacial modification of biocomposites was conducted through alkalization (sodium hydroxide solution) of fibres, compatibilization (using E-GMA) and/or coupling agent (MA -g-PE) to improve the interaction between components and the homogeneity of materials blending. Alkalization of fibres had improved the impact strength of biocomposites. The compatibilization and coupling effects on immiscible rPEHD/rPET blend and recycled polymer/RH filler, respectively, had led to an enhancement of mechanical performance and morphological stability. Scanning electron microscope micrograph revealed the improved matrix–matrix and filler–matrix interaction through interfacial modification. This investigation had shown that RHF mixed well with rPEHD/rPET/RHF to produce eco-friendly biocomposite products.

Effect of Alkali Treatment on Mechanical and Morphological Properties of Pineapple Leaf Fibre/Polyester Composites

In this study, our aim is to analyze the influence of fibre treatments and different fibre loading on mechanical, physical and chemical properties of pineapple leaf fibre reinforced polyester composites (PALF/PE). Fibre treatments were carried out with 1 N NaOH and KOH for 1 h. The untreated and treated PALF/PE composites were fabricated with 25 wt%, 35 wt% and 45 wt% fibre loadings by compression molding technique. Fourier Transform Infrared Spectroscopy (FTIR) was used to understand the effects of chemical treatment on PALF mechanical test results revealed that 45 wt% of PALF/PE composites treated with NaOH showed a 35% increase in tensile strength compared to untreated PALF/PE composites. The tensile modulus and the flexural module are also the highest at 45 wt% of KOH treated composites. The highest impact strength of 70 J/m was obtained for PALF/PE composites with NaOH treated fibres at 25% fibre loading. The results show that the fibre treatments in terms of the flexural and inter-laminar shear strength of composites were not effective. SEM of the tensile fractured specimen of PALF/PE composites revealed the changes in fibre characteristics due to the alkali treatment and less fibre pull-out at higher fibre loading. Overall we conclude that 1 N NaOH, 45 wt% treated PALF/PE composites satisfactorily and effectively improved both the mechanical and morphological properties. Obtained composites would be promising for construction materials, furniture and automotive components due to their superior strength and modulus at higher fibre loading.

Investigating the mechanical performance deterioration of Mediterranean cellulosic cypress and pine/polyethylene composites

The synergy of the materials physical characteristics, performance and recyclability become vital for industrial sustainability. However, finding a suitable cellulosic fiber type to form potential cellulosic-based composite and investigating performance deteriorations are of paramount importance to expand sustainable design possibilities for various applications. In this work investigations of the mechanical performance deterioration of both Mediterranean cellulosic pine and cypress fibers are experimentally investigated. This was achieved by utilizing the fibers with polyethylene matrix to reveal their potential capabilities for industrial applications. Numerous composites with various parameters like fiber types, fiber loading, fiber size, and reinforcement conditions were designed to study several characteristics of the cellulosic composites, their mechanical performance deteriorations, as well as determining the optimal fiber loading condition for each particular studied mechanical property of the composites. Results demonstrate that mechanical properties are significantly changed with fiber loading. In addition, the failure mode in the high fiber loading composites is an obvious indication of the improper or ineffective load transfer between the matrix and the cellulosic fiber. Moreover, it is revealed here that the performance of cypress fibers with polyethylene matrix is much better than that of pine for the considered properties with reference to the neat polyethylene matrix. The overall performance of both types of fibers with polyethylene clearly demonstrates that the performance of cypress fibers is much better than that of pine for all considered properties.

Property correlations for composites based on ethylene propylene diene rubber reinforced with flax fibers

EPDM composites filled with short flax fibers were prepared by melt blending procedure. The effects of fiber loading on the mechanical, thermal and water uptake characteristics were studied. The physico-mechanical, morphological thermal properties and water absorption behavior were discussed using tensile testing, differential scanning calorimetry, thermogravimetrical analysis and scanning electron microscopy. Scanning electron microscopy revealed that the flax fibers were well dispersed in the polymer matrix. The tensile strength and hardness of the composites were found to be improved at higher fiber loading. The water absorption pattern of EPDM/fiber composites at room temperature follows a Fickian behavior for composites with 10, 15 and 20 phr flax fiber.

The Determination of Interfacial Shear Strength in Short Fiber Reinforced Poly Ethylene Terephthalate by Kelly-Tyson Theory

The interfacial shear strength value measuring by the modified Kelly-Tyson equation method was studied the measurement accuracy. The measuring accuracy by using the modified Kelly-Tyson equation method is compared to the nano-indentation testing method. The results and an influential factor are described. An error in the modified Kelly-Tyson equation is verified to avoid the incorrect measurement when the interfacial shear strength was measured by the modified Kelly-Tyson equation. To study the different interfacial shear strength behavior, short fiber reinforced PET composites were fabricated. In this study, an advance fabricating technique for short fiber reinforced composite as direct fiber feeding process is conducted to fabricate GF/recycled PET for studying the interfacial shear strength. The result indicates that the modified Kelly-Tyson equation method accurately provides the accurate interfacial shear strength value, if it is conducted with the sample without a horizontally aligned fiber. So the high fiber loading content sample should be avoided to get the more accuracy result. The large horizontally aligned fiber area into specimens extremely resulted in the incorrect measurement of the interfacial shear strength value by the modified Kelly-Tyson equation method. The fiber agglomeration factor and the sensitively horizontally aligned fiber area must be considered its influence on the measuring for improving the equation effectiveness.