Cost-effective Processing Technology Research Articles

Transformation of Graphite Recovered from Batteries into Functionalized Graphene-Based Sorbents and Application to Gas Desulfurization.

The recycling and recovery of value-added secondary raw materials such as spent Zn/C batteries is crucial to reduce the environmental impact of wastes and to achieve cost-effective and sustainable processing technologies. The aim of this work is to fabricate reduced graphene oxide (rGO)-based sorbents with a desulfurization capability using recycled graphite from spent Zn/C batteries as raw material. Recycled graphite was obtained from a black mass recovered from the dismantling of spent batteries by a hydrometallurgical process. Graphene oxide (GO) obtained by the Tour's method was comparable to that obtained from pure graphite. rGO-based sorbents were prepared by doping obtained GO with NiO and ZnO precursors by a hydrothermal route with a final annealing step. Recycled graphite along with the obtained GO, intermediate (rGO-NiO-ZnO) and final composites (rGO-NiO-ZnO-400) were characterized by Wavelength Dispersive X-ray Fluorescence (WDXRF) and X-ray diffraction (XRD) that corroborated the removal of metal impurities from the starting material as well as the presence of NiO- and ZnO-doped reduced graphene oxide. The performance of the prepared composites was evaluated by sulfidation tests under different conditions. The results revealed that the proposed rGO-NiO-ZnO composite present a desulfurization capability similar to that of commercial sorbents which constitutes a competitive alternative to syngas cleaning.

Integrating genetic-engineered cellulose nanofibrils of rice straw with mild chemical treatments for enhanced bioethanol conversion and bioaerogels production

Cellulose in crop straws represents an abundant biopolymer convertible for biofuels and bioproducts, while the inherent recalcitrance of lignocellulose limits these applications. By selecting desirable rice mutant (cesa7) from site-mutation of the OsCESA7 isoform essential for cellulose biosynthesis, this study examined much improved lignocellulose recalcitrance such as reduced cellulose crystallinity, polymerization and nanofibril length for increased lignocellulose porosity and accessibility. Compared with its wild type, the cesa7 mutant showed a near-complete biomass saccharification with hexose yields of over 96% (% cellulose) for bioethanol production raised by 58%− 71% under three green-like pretreatments performed. Meanwhile, the cellulose substrate of cesa7 mutant was applied to produce aerogels with high porosity and large specific surface under less-intensity ultrasonic treatment, and its further mild chemical modification led to significantly raised oil adsorption capacity by 55%, mainly due to higher proportion of nanofibrils and the honeycomb-like fibers structure observed. It has thus provided an applicable approach for high-yield bioethanol and high-quality aerogels by integrating genetic-modified cellulose substrates with cost-effective process technology.

Fabrication of Panel-Level Glass Substrates with Complete Design Freedom using LIDE

In this work, we present examples of highly reproducible, accurate and extremely cost-effective wafer- and panel-level fabrication of glass interposers, free of any process-dependent design limitations where any distribution and density of Through-Glass Vias (TGV) with any cross-section geometries and aspect-ratios, is possible. Glass has recently garnered significant interest for its many applications in the semiconductor packaging industry, particularly as a core substrate material for interposer applications. Glass has a unique set of material properties with great relevance for this industry, such as very high electrical resistivity, low loss tangent and low dielectric constant. Glass also exhibits low warpage due to its relatively low Young‘s Modulus while still being compatible with Silicon in terms of CTE and, when processed using a technology that doesn’t induce the generation of any defects such as microcracks or thermally-induced stress, it is highly reliable during processing and operation. Laser Induced Deep Etching (LIDE®) technology is a 2.5D glass processing technology with complete design freedom purposedly developed for cost-effective, high-volume fabrication of defect-free glass components. Despite its many advantages as an interposer material in relation to Si, its application has been hindered by the lack of reliable, precise, and cost-effective processing technologies. LIDE® consists of a two-step process: i) a very fast maskless and direct-write laser process induces subtle and very localized modification in the glass substrate, requiring a single laser pulse to modify the whole glass thickness; and ii) a wet-etching process done in batch, where the whole glass substrate is subjected to the action of an etchant and where the removal of glass occurs at an accelerated rate in the laser-modified regions. This process flow allows LIDE to fabricate several thousands of TGV per second, completely free of any defects, with a sub-micron point-to-point accuracy and ± 5 µm accuracy (cumulative) across a 510 mm x 515 mm glass panel (Cp > 1.33), in any glass type, with aspect-ratios from 1:10 to 1:50 (diameter:depth).

Women cassava processors’ livelihood; implications for improved processing technology usage in Nigeria

The study compared the impact of the use of conventional and improved cassava processing technologies on the livelihood of women processors in north central Nigeria. This study adopts a quantitative method using a well-structured interview schedule for data collection from 410 respondents. Descriptive and inferential statistics such as an independent two-sample t-test was used to analyze the data. The majority of respondents were married and between the ages of 31 and 50. The mean years of education for improved technology users (ITU) were 8 years, while that of conventional technology users (CTU) was 10 years. Majority of both ITU (88.9%) and CTU (63.9%) had more than 10 years of processing experience. Majority of ITU (89.2%) and CTU (97.1%) were educated. A little above average (ITU - 53.7% and CTU - 50.2%) had medium household sizes and average annual income of ITU: N = 528,654 and CTU: N = 294,610. It was found that improved technology users had a very high livelihood status, while conventional technology users had a low livelihood status (ITU 75.25 and CTU 52.50) which indicated that the use of improved technology enhanced women’s contribution to family welfare and improved their livelihood. The results of the independent two-sample t-test show that there is a significant difference between the livelihood of improved and conventional technology users (t = −18.614, p = 0.000). The government should therefore focus on the development of appropriate and cost-effective farm-level processing technologies and further encourage the promotion of improved investment heavily in subsidized cassava processing machinery to afford processors to acquire these machines at a reasonable cost.

Sustaining Protein Nutrition Through Plant-Based Foods.

Proteins are essential components of the human diet. Dietary proteins could be derived from animals and plants. Animal protein, although higher in demand, is generally considered less environmentally sustainable. Therefore, a gradual transition from animal- to plant-based protein food may be desirable to maintain environmental stability, ethical reasons, food affordability, greater food safety, fulfilling higher consumer demand, and combating of protein-energy malnutrition. Due to these reasons, plant-based proteins are steadily gaining popularity, and this upward trend is expected to continue for the next few decades. Plant proteins are a good source of many essential amino acids, vital macronutrients, and are sufficient to achieve complete protein nutrition. The main goal of this review is to provide an overview of plant-based protein that helps sustain a better life for humans and the nutritional quality of plant proteins. Therefore, the present review comprehensively explores the nutritional quality of the plant proteins, their cost-effective extraction and processing technologies, impacts on nutrition, different food wastes as an alternative source of plant protein, and their environmental impact. Furthermore, it focuses on the emerging technologies for improving plant proteins' bioavailability, digestibility, and organoleptic properties, and highlights the aforementioned technological challenges for future research work.

Material composition analysis and process flow development for the porphyry copper ores of the Yoshlik-1 deposit

The purpose of this research was to analyze the material composition of porphyry copper ores of the Yoshlik-1 deposit (Uzbekistan) and select a cost-effective processing technology for them. It has been found that the deposit has gold- and molybdenum-bearing ores, composed by 83.84–87.68 % of lithophilic components with a distinct silica prevalence (51.6 %). The mass fractions of quartz and feldspars in the sample are 17 and 40 %, respectively. The total mass fraction of alkali and alkaline earth metals is 16.03 %. The mass fraction of carbon is 0.25 %. All carbon is found in carbonates. The mass fraction of iron is 5.12 %, with oxidized iron being the predominant form. According to the sieve analysis data, the mass fraction of copper in the ore samples is 0.34 %. The grain-size analysis showed a sample gold grade of 0.38 g/t. The valuable components are copper, molybdenum, gold, and silver with the grades of 0.34 wt%, 0.0054 wt%, 0.38 g/t and 0.73 g/t, respectively. A centrifugal concentrator was used for a preliminary assessment of free gold recovery into the gravity concentrate. A series of flotation experiments were carried out to select the collector types and rates for the flotation of ore ground to the 70 % passing –0.074 mm class. Potassium butyl xanthate, 442F, and MX5125 were used as collectors at various rates. Based on the results of the studies, a combined gravity/flotation concentration process was recommended for the ore of the Yoshlik-1 deposit.

Study of the Form of Minerals in Copper Porphyry Ores of “Yoshlik-I” Deposit

The purpose of these studies is to study the forms of finding copper-porphyry ores of the Yoshlik I deposit compared with the Kalmakyr deposit data and to decide on the choice of a cost-effective ore processing technology. As a result of the studies, it was revealed that ore mineralization is represented by sulfides of various metals and iron oxides. The primary sulfides are pyrite and chalcopyrite. In the «Yoshlik-I» sample, the pyrite content is six times less than in the Kalmakyr sample and is 0.7%. The mass fraction of chalcopyrite in the Kalmakyr and “Yoshlik-I” deposits is 1.1 and 0.8%, respectively. The remaining sulfides of various metals and the minerals of these ribs are present in several single signs. According to the content of cell fids, the Kalmakyr ore sample is characterized by a small-sulfide ore; the «Yoshlik-I» ore sample is a slab-sulfide type ore. According to the oxidation state calculated by iron, ore samples of the Kalmakyr and «Yoshlik-I» deposits belong to the mixed variety of ores.

(Invited) Oxide-Based All-Solid-State Batteries Prepared By Aerosol Deposition

Oxide-based all-solid-state batteries (OX-SSBs) have been expected as next generation rechargeable batteries. Although various kinds of high Li+ conductive solid electrolytes have been prepared such as Li7La3Zr2O12 (LLZ), NASICON-structured Li1.3Al0.3Ti2(PO4)3 (LATP), LiTaPO4 etc, there are serious problems to develop low-resistive positive electrode/high Li+ conductive solid electrolyte interface. Because these high Li+ conductive solid electrolytes are crystallized at 800-1000 ℃, high temperature sintering is common way to combine them with conventional crystalline insertion electrode materials (LiCoO2 (LCO), LiNi1/3Co1/3Mn1/3O2 (NCM111) etc). However, both electrodes and solid electrolytes are composed of different elements with different concentrations, such high temperature sintering process frequently provide mutual diffusion region around the interface in addition to structural degradation and then seriously impede the interfacial resistance. Thus, one strategy to prevent those side reactions will be to apply low temperature sintering or densification process. We have focused on aerosol deposition, AD, a room temperature ceramic coating process. AD can realize quick speed and wide area ceramic coating and has been estimated as a cost-effective process technology for oxide-based energy conversion devices. AD make it possible to prepare electrode-solid electrolyte composite electrodes at room temperature and LiCoO2 film electrode on LiPON film. In addition, AD enables us to investigate the effects of annealing temperature on the interfacial resistances and then limiting temperature for sintering.In this presentation, our recent works on Ox-SSBs using the AD will be introduced 1) 4V- and 5V-class bulk-type Ox-SSBs, 2) effects of annealing temperature on interfacial resistivity, an example of LCO-LATP system to determine limiting temperature for sintering.

Effects of thermal modification on physical and mechanical properties of Mozambican Brachystegia spiciformis and Julbernardia globiflora wood

Mozambique’s large pool of tropical hardwoods is hampered by the prevalence of low-grade tree species along with a lack of cost-effective processing technologies to improve timber properties. Brachystegia spiciformis and Julbernadia globiflora are the most abundant tree species in terms of volume in the country, but with limited use due to their low timber quality. In this study, thermal modification at three different temperatures (215 °C; 230 °C; 245 °C) was applied for 2 h to the timber of both species, followed by measurement of a set of physical and mechanical wood properties. The results show that the originally light-coloured sapwood of both tree species darkened gradually as the intensity of thermal modification increased. Additionally, from untreated samples to the highest thermal treatment level, timber of B. spiciformis incurred a maximum mass loss of 27%, while oven-dry density was reduced from 0.65 to 0.56 g/cm3 and equilibrium moisture content (EMC) changed from 7 to 3%. Timber of J. globiflora had a mass loss of 23% after the highest treatment level, an oven-dry density reduction of 0.81 to 0.74 g/cm3 and an EMC decrease from 8 to 3%. The changes in mechanical properties from reference samples to the highest thermal treatment level were also significant. For B. spiciformis, MOE decreased by 10.2%, MOR by 50.8%, compression strength parallel to the grain by 29.2% and Brinell hardness by 23.5%. Timber of J. globiflora followed the same trend with an MOE decrease by 6.9%, an MOR decrease by 53.2% and a decrease in compression strength parallel to the grain by 21.9%. All tested wood properties showed significant responses to thermal modification after the most intensive treatment level had been applied. Despite the degradation of mechanical properties in both species, an optimal combination of temperature and treatment time could be achieved. The recorded changes of the tested wood properties in both species could increase the range of applications; the new colour resembled that of highly sought-after tropical hardwoods.

Distinct mechanisms of enzymatic saccharification and bioethanol conversion enhancement by three surfactants under steam explosion and mild chemical pretreatments in bioenergy Miscanthus

Miscanthus is a leading bioenergy crop that represents an enormous lignocellulose resource for biofuels and bioproducts. However, as lignocellulose recalcitrance leads to financially inviable bioethanol production and the potential of secondary wastes into the environment, it becomes crucial to explore green-like and cost-effective biomass processing technologies. To address these issues, low doses of chemical surfactants have been added to enhance biomass enzymatic hydrolysis and bioethanol conversion, but much remains unknown about the mechanism of enhancement. For first time, in this study, a novel chemical surfactant (1% Silwet L-77) was applied to enhance the enzymatic hydrolysis of raw Miscanthus straw, and 40% cellulose digestion was achieved, which is 1.2- and 4.5-fold higher than that of two well-known surfactants (PEG-4000 and Tween-80), respectively. Using lignocellulose substrates obtained from Miscanthus biomass samples that were pretreated by green-like steam explosion followed by mild chemical (NaOH or H2SO4) pretreatments, supplementation with the three surfactants led to significantly enhanced enzymatic saccharification. The 2% Tween-80 supply resulted in a hexose yield of 99% (% cellulose) from enzymatic hydrolysis, followed by 95% with 0.5% PEG-4000 and 71% with 1% Silwet L-77. Despite the slightly lower hexose yield, Silwet L-77 resulted in consistently higher sugar-ethanol conversion rates in all lignocellulose substrates examined. Furthermore, based on the enzyme profiling of mixed cellulase adsorption on lignocellulose and the chemical analysis of wall polymer features and lignocellulose accessibility, this study proposed multiple hypothetical models to interpret the distinct enhancement roles of three surfactants in the enzymatic hydrolyses of diverse lignocellulose substrates. These models also provide a powerful strategy for low-cost bioethanol production with the potential for high-value bioproducts by using desirable surfactants in Miscanthus and other bioenergy crops.

Novel, non-thermal hydrodynamic cavitation of orange juice: Effects on physical properties and stability of bioactive compounds

Effect of hydrodynamic cavitation (HC) at pressure 3–15 bar and treatment time5–25 min on physical and chemical qualities of orange juice was investigated. Processing parameters were optimized on the basis of retention of vitamin C and antioxidant activity; inactivation of pectin methyl esterases (PME) and peroxidase (POD) enzyme and stability of pH, °Brix, viscosity, titratable acidity and total color difference. HC of orange juice at 5 bar 15 min and 13 bar 10 min resulted into maximal overall desirability at 0.52 and 0.40 respectively. No significant change in °Brix, pH, titratable acidity for fresh and cavitated orange juice was observed. Only 21% and 13% of reduction in PME and POD respectively was recorded. A 94% and 91% of antioxidant activity and vitamin C retention was noted in both optimized samples. This study demonstrated that HC can produce orange juice more economically with better physical properties and nutritional value. Industrial relevanceThe demand for more natural, preservative free with highest nutritional bioactive containing juices has created a need of non-thermal processing. Hydrodynamic cavitation (HC) processing is novel, emerging and under explored technology for fruit juices. HC due to the formation of cavities and shock waves causes enzyme and microbial inactivation at low temperature while retaining natural bioactives with fresh-like organoleptic characteristics. It is believed worldwide that non thermal technologies like HC will be among the most cost effective, scalable and impactful liquid food processing technologies in the coming decades especially for commercial products.

Selectively Desirable Rapeseed and Corn Stalks Distinctive for Low-Cost Bioethanol Production and High-Active Biosorbents

Crop straws provide large amounts of biomass resource for biofuels, but it remains to explore cost-effective lignocellulose process technology with additional valuable bioproducts. Using total eight rapeseed and corn stalks with distinct lignocellulose composition, this study initially performed mild alkali pretreatment (1% NaOH, 50 °C) for enzymatic hydrolysis and yeast fermentation to release bioethanol yields varied from 5 to 12% (% dry matter). By comparison, four corn stalks consistently showed more ethanol yields than those of the rapeseeds, but relatively higher sugar-ethanol conversion rates were examined in the rapeseed samples. Of all stalk samples, both genetic corn mutant (CY04) and classic rapeseed cultivar (Bn18) were respectively assessed as the desired lignocellulose residues for relatively high bioethanol production. Then, all remained solid residues of yeast fermentation were employed as biosorbents for Cd adsorption under various incubation conditions (pH, temperature, time, Cd concentration, biosorbent dose). In general, the solid residues exhibited much higher Cd adsorption capacities and removal rates than those of the raw stalks. In particular, two desirable rapeseed residues were of the highest Cd adsorption capacities, compared to the corn residues examined in this study or other major agricultural crop straws as previously reported. Furthermore, the solid residues were characterized as typical biosorbents via a classic chemical binding manner with much large surface areas accountable for their high Cd adsorption capacity. Therefore, this study has demonstrated a green-like strategy for low-cost cellulosic ethanol production and high-active biosorbents by selecting desired corn and rapeseed stalks.

The development of synthetic analogues of glycosaminoglycans for the cost-effective modification of contact lens surfaces

Purpose Medical devices benefit from increasingly sophisticated mimics of bodily tissues; contact lenses are no exception and additionally rely on cost-effective process technology. Bodily hydration is often regulated by sulfated glycosaminoglycans (GAGs, e,g. chondroitin sulfate). Hydration is particularly important in dermal, ocular and orthopaedic (cartilage and intervertebral disc) applications. This poster describes synthetic approaches to harness synthetic GAG analogues in the cost-effective modification of contact lens surfaces.

Low-Complexity Adaptive Chromatic Dispersion Estimation Scheme Using Machine Learning for Coherent Long-Reach Passive Optical Networks

In the coherent long-reach passive optical networks (LRPON), it is crucial to propose cost-effective digital signal processing (DSP) technologies to reduce the overall complexity and power consumption. This paper has proposed a low-complexity chromatic dispersion (CD) estimation scheme based on deep neural networks (DNN) and the error vector magnitude (EVM). To add comparisons, the performances of CD estimation schemes using other two well-known machine learning algorithms including the k-nearest neighbor (KNN) and the decision tree (DT) have also been investigated. The simulation results show that the proposed CD estimation scheme is effective in the coherent LRPON with the quadrature phase shift keying (QPSK) and 16-ary quadrature amplitude modulation (QAM) systems at 14Gbaud rate, 28Gbaud rate and 56Gbaud rate. The comprehensive performances of the DNN outperform those of the KNN and the DT. The mean estimation error of the DNN is less than 20ps/nm within the 100 km access distance in the 28Gbaud QPSK/16QAM systems. What's more, compared with classical methods using the CD scanning and frequent domain equalizers (FDE), the computation complexity of the proposed CD estimation scheme based on the DNN-EVM has been respectively reduced by 72.3 times, 86.7 times and 2.8 times about the amount of multipliers, adders and comparators.

Integrated silicon nitride organic hybrid DFB laser with inkjet printed gain medium

The provision of a coherent light source is a prerequisite for a variety of photonic integrated circuits. The integration of semiconductor laser diodes in disposable photonic devices in fields such as biosensing is, however, impeded by the competitive pricing in this application area. In this work, we demonstrate lasing of an alternative laser light source, namely an integrated hybrid organic solid-state distributed feedback laser for a silicon nitride photonic platform. The laser is optically pumped with a high power 450 nm laser diode and emits in the visible at 630 nm into a waveguide taper to reduce the cross-section to a single mode geometry. Inkjet printing of the organic gain medium enables a local, cost-effective, and flexible processing technology. The fabrication of the presented coherent light source is CMOS compatible and therefore highly interesting for co-integrated sensing platforms.

Emergent food proteins - Towards sustainability, health and innovation.

There is an increasing demand for alternative and sustainable protein sources, such as vegetables, insects and microorganisms, that can meet the nutritional and sensory pleasantness needs of consumers. This emergent interest for novel protein sources, allied with "green" and cost-effective processing technologies, such as high hydrostatic pressure, ohmic heating and pulsed electric fields, can be used as strategies to improve the consumption of proteins from sustainable sources without compromising food security. In addition to their nutritional value, these novel proteins present several technological-functional properties that can be used to create various protein systems in different scales (i.e., macro, micro and nano scale), which can be tailored for a specific application in innovative food products. However, in order for these novel protein sources to be broadly used in future food products, their fate in the human gastrointestinal tract (e.g., digestion and bioavailability) must be assessed, as well as their safety for consumers must be clearly demonstrated. In particular, these proteins may become novel allergens triggering adverse reactions and, therefore, a comprehensive allergenicity risk assessment is needed. This review presents an overview of the most promising alternative protein sources, their application in the production of innovative food systems, as well as their potential effects on human health. In addition, new insights on sustainable processing strategies are given.

Mild physical and chemical pretreatments to enhance biomass enzymatic saccharification and bioethanol production from Erianthus arundinaceus

Diverse cell wall compositions were subjected to pretreatment and saccharification to produce bioethanol from 20 Erianthus arundinaceus accessions. Using four typical pairs of biomass samples, various physical and chemical pretreatments were employed to extract cell wall polymers. Mild chemical pretreatment (2% NaOH and 50 °C) yielded complete biomass saccharification, whereas the liquid hot water pretreatment achieved the highest bioethanol yield with a full sugar-ethanol conversion rate. Notably, the extraction of the lignin p-coumaryl alcohol (H) monomer greatly enhanced biomass saccharification, which may be attributed either to the improved accessibility of cellulose to enzymes after effective removal of lignin or to the maintained native cellulose microfibrils from the relatively less co-extraction of hemicellulose. Hence, the results suggested that the H-monomer-rich lignin may slightly associate with cell wall networks for greatly enhanced lignocellulose enzymatic hydrolysis after mild pretreatments. The present findings provide a strategy for both cost-effective biomass process technology and precise lignocellulose modification for bioenergy.

Turbo thin film continuous flow production of biodiesel from fungal biomass

Direct biodiesel production from wet fungal biomass may significantly reduce production costs, but there is a lack of fast and cost-effective processing technology. A novel thin film continuous flow process has been applied to study the effects of its operational parameters on fatty acid (FA) extraction and FA to fatty acid methyl ester (FAME) conversion efficiencies. Single factor experiments evaluated the effects of catalyst concentration and water content of biomass, while factorial experimental designs determined the interactions between catalyst concentration and biomass to methanol ratio, flow rate, and rotational speed. Direct transesterification (DT) of wet Mucor plumbeus biomass at ambient temperature and pressure achieved a FA to FAME conversion efficiency of >90% using 3 wt/v % NaOH concentration, if the water content was ≤50% (w/w). In comparison to existing DT methods, this continuous flow processing technology has an estimated 90–94% reduction in energy consumption, showing promise for up-scaling.

Using High Pressure Processing for Bioconversion of Hazelnut Shells to Generate Fermentable Sugars

Development of cost-effective process technologies to produce biofuels and enzymes from lignocellulosic materials has gained importance. However, few studies have considered high pressure processing (HPP) as an emerging technology for the bioconversion of lignocellulosic biomass. This study aimed to determine and optimize the effect of HPP combined with dilute acid and enzymatic saccharification on the production of fermentable sugars from hazelnut shells. Optimization via response surface methodology was carried out for acid concentration of 1 to 3% (w/v) for a pretreatment time of 10 to 30 min at a pressure range of 200 to 500 MPa. The combined HPP processes were evaluated in terms of the production of total reducing sugars. The optimized total reducing sugar production was estimated at 473.4 mg/g, with production of 88.4% fermentable sugars under 2.9% H2SO4 for 10 min at 350 MPa. The results implied a 2.4 fold increase in fermentable sugar production under the optimized conditions using combined HPP. The combined HPP process appeared to significantly lower costs due to the decreases in pressure requirement, liquid consumption, and pretreatment time.

Injection molding of polypropylene hybrid composites reinforced with carbon fiber and wood fiber

Hybrid composites are made by incorporating two or more different types of fillers in a single matrix that is highly tailorable. Carbon fiber (CF) reinforced composites have been well developed for certain industries such as aerospace and sporting goods. However, the high cost of carbon fiber, as well as lack of cost effective processing technologies for mass production, prevents its penetration to many different markets. Wood fiber (WF), an environmentally sustainable bio‐fiber, has been used widely in making wood/plastic composites (WPCs) for building products and automotive applications, due to its low cost and lightweight. Nevertheless, WPCs have very limited structural applications where strong mechanical properties are required. Incorporating CF and WF into a polymer matrix to make hybrid composites through injection molding, would be a path to expanded applications for both. This paper investigated the injection molding of CF‐WF/polypropylene hybrid composites and their mechanical properties. The effects of fiber content and hybridization on the mechanical properties were studied. POLYM. COMPOS., 39:3329–3335, 2018. © 2017 Society of Plastics Engineers