Direct Fiber Feeding Injection Molding Research Articles

Effect of de-sizing on the structural and mechanical properties of carbon fiber reinforced polypropylene composites molded by the novel direct fiber feeding injection molding technology

Carbon fiber reinforced thermoplastic composites are rapidly emerging as alternative materials for auto parts due to recyclability, excellent stiffness, and strength to weight ratio. In the present study, the influence of carbon fiber de-sizing on the structural and mechanical properties of the sized and de-sized Carbon Fiber Reinforced Polypropylene (CFPP) composites molded by the recently developed novel Direct Fiber Feeding Injection Molding technology was studied. The effect of carbon fiber de-sizing on the structural properties was studied from the fiber dispersion status, fiber orientation factor, fiber volume fraction, and the fiber length. The surface morphology of the sized and de-sized carbon fibers was studied from the Scanning Electron Microscopy (SEM) and Atomic Force Microscope images. The static mechanical properties were studied based on the tensile tests at different loading rate and temperature. The Dynamic Mechanical Analysis tests were conducted to analyze the dynamic viscoelastic behavior of the sized and de-sized CFPP composites. The SEM images were used to observe the failure mechanism. The preliminary results indicated that de-sized composites had better fiber dispersion as compared to the sized CFPP composites. It was found that de-sizing the carbon fiber surface does not significantly affect the carbon fiber length, fiber volume fraction, and fiber orientation in the CFPP composites. Also, the de-sized composites showed better static and thermodynamic mechanical properties caused by the enhanced fiber matrix interaction in CFPP composites as compared to the sized CFPP composites. [Formula: see text]

Jute Fiber Reinforced Thermoplastic Composites Fabricated by Direct Fiber Feeding Injection Molding (DFFIM) Process

In this research, jute fiber reinforced polypropylene and poly (lactic acid) composites were fabricated, respectively by Direct Fiber Feeding Injection molding (DFFIM) process. Jute spun yarns were directly fed into the barrel of molding process in order to eliminate the fiber breakage during extrusion compounding process. Mechanical properties of both composites were investigated by tensile testing and morphological properties were characterized by scanning electron microscopy (SEM). For jute reinforced polypropylene (PP) composites, tensile strength of composite decreased but modulus increased, compared with neat PP. The using maleic anhydride grafted polypropylene (MaPP) can improve interfacial bonding between jute fiber and PP matrix as observed by SEM, which resulted in the increasing of tensile strength. Therefore, in the case of jute/PLA composites, jute fibers surface treated with sodium hydroxide (NaOH) and silane coupling agent to improve interfacial adhesion. The tensile strength of untreated-jute/PLA composites are not different with PLA matrix but tensile modulus of untreated composites are higher than PLA matrix. In addition it is found that the tensile properties of NaOH-treated jute/PLA and NaOH+Silane-treated jute/PLA composites were improved, compared with untreated composites.

Damage behavior of low velocity impact test on glass fiber reinforced poly (ethylene terephthalate) composites

In this study, to enhance the properties of recycled poly (ethylene terephthalate) (r-PET), the direct fiber feeding injection molding (DFFIM) process with un-modified and modified check ring designs were used to fabricate glass fiber reinforced recycled PET (GF/r-PET) composites. The new generated GF/r-PET composites were performed and compared with commercial GF/PET composites to extensive study on the impact properties. The results indicate that the distributional fiber length in the range of 0-800 μm of conventional injection molding process lead to the brittle fracture behavior and low absorbed energy. More existing fiber length in the range of 1000-3800 μm of DFFIM un-modified check ring develops the impact properties as more ductile behavior and energy absorption especially in the initial damage stage. Meanwhile, 3800-8000 μm remaining fiber length provided a small increase in the initial internal damage stage compared to those of 0-3800 μm but it efficiently improves the absorbed energy at the damage propagation energy stage.

Mechanical properties and fiber characteristics of glass fiber/carbon fiber reinforced polyethylene terephthalate hybrid composites fabricated by direct fiber feeding injection molding

Abstract Improving the applicability of polyethylene terephthalate (PET) by carbon fiber/glass fiber reinforcement is of great interest. Glass fiber (GF)/carbon fiber (CF)/PET hybrid composites were fabricated by direct fiber feeding injection molding (DFFIM) process. The aim of DFFIM is to obtain longer fibers in composites in order to improve their mechanical properties. In this study, the mechanical properties of GF/PET composites fabricated by conventional injection molding and hybrid GF/CF/PET composites fabricated by DFFIM process were investigated. The influence of GF and CF volume fractions on fiber distribution, fiber orientation, and fiber length is discussed. Fiber distribution status was quantitatively measured by the fiber distribution index. Fiber agglomeration problem was observed by scanning electron microscopy. The results indicate that incorporating CF in GF/CF/PET hybrid composites by the DFFIM process greatly enhances mechanical performance even when only a small amount of CF is added. Too high GF content leads to less effective CF hybridization because it causes poor fiber distribution and poor fiber orientation and intensifies fiber attrition. The ideal volume fractions of GF and CF for fabricating GF/CF/PET hybrid composites by using DFFIM are provided.

Glass fiber–reinforced polypropylene composites fabricated by direct fiber feeding injection molding

Abstract This article investigates the effect of process parameters on the mechanical properties of polypropylene-glass fiber (GF/PP) composites made using a new injection molding method known as direct fiber feeding injection molding (DFFIM). In the DFFIM process, continuous fibers are directly guided into the barrel of the injection molding machine through the designed vent and are fed into the polymer melt by the shearing motion of the screw of the injection molding machine during the plasticization process. The DFFIM process improves the fiber length and avoids excessive fiber attrition, resulting in enhanced mechanical properties in the composites. The effect of process parameters on the mechanical properties of manufactured composite specimens is discussed based on the results of tensile tests, three-point flexural tests, and Izod impact tests. Scanning electron microscopy was performed on the fracture surfaces to observe cross-section morphology. There is a fiber agglomeration phenomenon that occurs in the core layer of GF/PP composites made using DFFIM. The number of fiber rovings, number of fiber filaments, matrix feeding speed, and screw speed influence the GF content and distribution in the composites, ultimately affecting the mechanical properties.

Structure and interfacial shear strength of polypropylene-glass fiber/carbon fiber hybrid composites fabricated by direct fiber feeding injection molding

The structure and interfacial shear strength (IFSS) of polypropylene-glass fiber/carbon fiber hybrid composites fabricated by a new method called direct fiber feeding injection molding (DFFIM) process were investigated based on the skin-core-skin structure and modified Kelly-Tyson equation, respectively. The fiber dispersion state was evaluated qualitatively by scanning electron microscopy (SEM) and quantitatively by the fiber distribution index (FDI). Carbon fiber agglomeration is more likely to occur in hybrid composites and was present in the core layer of DFFIM composites in this study. However, glass fiber has shown relatively uniform dispersion in hybrid composites with a greater tendency to be distributed in the skin layers. This is attributed to the difference in feeding method, where glass fibers were fed through the hopper while carbon fibers were inserted from the vent hole. The IFSS between fibers and polypropylene of different composites in different layers is discussed by considering fiber length and orientation distributions in the core and skin layers, respectively.

Polypropylene–glass fiber/basalt fiber hybrid composites fabricated by direct fiber feeding injection molding process

ABSTRACTHybrid composites of polypropylene reinforced with glass fibers and basalt fibers were fabricated by vented injection molding machine which is named the direct fiber feeding injection molding (DFFIM) process. Polyamide 6 and maleic anhydride‐grafted polypropylene has been used as a coupling agent to improve the interfacial bonding between the fibers and matrix. Two types of vented injection molding machines with a different check ring and mold were used for making specimens. The fiber lengths were analyzed to identify the most suitable check ring and mold for the DFFIM process. The mechanical properties of the hybrid composites were investigated by tensile, flexural and Izod impact tests. The interfacial morphology of the fractured tensile specimens was studied by using scanning electron microscopy and showed that there is a fiber agglomeration phenomenon that occurs in the hybrid composites, and it has a significant effect on the mechanical properties of hybrid composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45472.

Tensile properties of glass fiber reinforced polypropylene composite and its carbon fiber hybrid composite fabricated by direct fiber feeding injection molding process

The elastic modulus of a glass fiber reinforced polypropylene composite and its hybrid carbon fiber composite fabricated by direct fiber feeding injection molding (DFFIM) process were evaluated by using the Classical Calculated Method and the modified Tsai‐Hill criterion based on the laminate analogy approach method, respectively. The results were in good agreement with the experiments for both the glass fiber reinforced polypropylene composite and its hybrid composite. In addition, the modified Tsai‐Hill criterion shows more accuracy than the Classical Calculated Method in predicting the Young's modulus. The tensile strength of the composites was investigated by utilizing the modified Kelly‐Tyson equation and Modified Tsai‐Hill criterion. The results of the modified Kelly‐Tyson equation are closer to the real value. The interfacial shear strength between carbon fiber and polypropylene in the hybrid composite manufactured by the DFFIM process was analyzed by using the modified Kelly‐Tyson equation. POLYM. COMPOS., 39:3564–3574, 2018. © 2017 Society of Plastics Engineers

Study on the Effective of Utilization in Vent-Type Injection Molding

. In this study, characteristics of glass fiber reinforced recycled-PET composites by using direct fiber feeding injection molding (DFFIM) process were studied. The results, when varied processing conditions, indicated that decreasing of matrix feeding screw speed and increasing of number of glass fiber led to the increasing of fiber loading content, respectively. The average fiber length of glass fiber tended to decrease with the increasing of fiber loading content. Tensile modulus and tensile strength exhibited almost linear correlation with glass fiber load content. For study on stability of DFFIM process performance, at earliest stage of DFFIM process, discarding of at least five injected shots must be done in order to prepare the system availability of DFFIM process. The DFFIM machine could uninterruptedly manufacture composites without any problems occurred during 7 hours, which consequently provided high stability of product quality with long-term fabrication.

Mechanical Properties of Composite Compounded with ABS (GF) and CF by DFFIM

The direct fiber feeding injection molding (DFFIM) process is the new fabrication technique. This technique is able to eliminate the compounding process. In this study, the composite consisting of glass fiber/carbon fiber/ABS (GF/CF/ABS) were fabricated. Tensile, bending and Izod impact test were conducted to compare mechanical properties between glass fiber and glass fiber/carbon fiber hybrid composites. The additional of carbon fiber improved tensile, bending and impact properties of the hybrid composites. SEM photographs indicated that carbon fiber tended to agglomerate during DFFIM process. It can be noted that the low content of carbon fiber was suitable for enhanced mechanical performances of GF/CF/ABS hybrid composites.

Mechanical Properties of Injection Molded Products Fabricated by Direct Fiber Feeding Injection Molding

Direct-fiber-feeding injection molding (DFFIM), with the improvement of the screw and cylinder and a fiber-direct-feeding method, is a new way to make short fiber reinforced composite material from one step by throwing fiber into a formation machine directly, in which the traditional compounding process can be unnecessary. At current study, the well-distributed fiber and improved interface/interphase between fiber and plastic are aimed to achieve a cost-performance-ratio, through those achievements such as design of screw or the other combination conditions during DFFIM process. As for carbon fiber, besides filaments, there are many types including tow, staple yarn, chopped strands, compound, and so on. Those different reinforcement forms were adopted and used to make CFRP by DFFIM to investigate their mechanical properties. In particularly in this paper, PA6 resin and CF/PA66 commingle yarn was used as matrix and reinforcements for comparison. It is observed that the SEM dispersion state and interface /interphase increased.

The Effect of Processing Parameter on Mechanical Properties of Short Glass Fiber Reinforced Polyoxymethylene Composite by Direct Fiber Feeding Injection Molding Process

This research describes the effect of processing parameters as matrix feeding speed, screw rotational speed and cylinder temperature of direct fiber feeding injection-molded process on properties of short glass fiber reinforced polyoxymethylene composite. The increasing of matrix feeding speed at screw rotational speed of 172rpm led to the reduction of fiber loading content and increasing of fiber length. Whereas the higher screw rotational speed impacted on the increasing of fiber loading content and fiber length. However, its tensile properties were lower than the molded at screw rotational speed 172rpm. When fiber loading content over 20wt.%, tensile strength of both conditions reached the same values because the poor fiber distribution especially at screw rotational speed of 258rpm. Then Kelly – Tyson's equation was used to predict their tensile strength. It was found that tensile strength at maximum fiber loading content at screw rotational speed of 172rpm and 258rpm are lower than the calculated strength values around 28.9% and 31.8%, respectively. The effect of cylinder temperature was also elucidated.

PolyOne promotes new additives at Interplas

Direct-fiber-feeding injection molding (DFFIM), with the improvement of the screw and cylinder and a fiber-direct-feeding method, is a new way to make short fiber reinforced composite material from one step by throwing fiber into a formation machine directly, in which the traditional compounding process can be unnecessary. At current study, the well-distributed fiber and improved interface/interphase between fiber and plastic are aimed to achieve a cost-performance-ratio, through those achievements such as design of screw or the other combination conditions during DFFIM process. As for carbon fiber, besides filaments, there are many types including tow, staple yarn, chopped strands, compound, and so on. Those different reinforcement forms were adopted and used to make CFRP by DFFIM to investigate their mechanical properties. In particularly in this paper, PA6 resin and CF/PA66 commingle yarn was used as matrix and reinforcements for comparison. It is observed that the SEM dispersion state and interface /interphase increased.