Properties Of Fibers Research Articles

Heat treatment effects on the shear performance and microstructure evolution of W-core SiC fibers

SiC fiber reinforced titanium alloy matrix composites employed in elevated temperature aeroengine components are subjected to complex loading conditions. Investigating the shear performance of SiC fibers after heat treatment can help ensure the load-carrying capability of composites at service temperatures. This study presents a novel double shear testing method for W-core SiC fibers. The shear strength and stiffness of the SiC fibers in as-received and heat-treated conditions were measured. The morphologies of SiC fibers’ shear fracture surfaces and C coatings were thoroughly analyzed. The evolution of the internal microstructure and the composition of reaction layers after heat treatments were investigated. The shear strength of W-core SiC fibers at 95% survival probability reached 588.64MPa after 200 h of heat treatment at 600°Celsius, representing a 55% improvement over both the as-received and 1100°Celsius heat-treated conditions. After heat treatment at 1100°Celsius, the reaction layer between the W core and the SiC sheath thickened exponentially due to extensive elemental diffusion, resulting in the formation of numerous Kirkendall voids. The voids facilitated crack initiation and propagation, leading to a deterioration in fiber shear performance. The insights gained in this study regarding the shear properties of SiC fibers can provide support for predicting the mechanical performance of composites under complex loading conditions.

Using higher rates of stabilization of a wet-spun pan fibre to understand the effect of microstructure on the tensile and compressive properties of carbon fibre

The transformation of a polyacrylonitrile (PAN) precursor fibre into carbon fibre using varying stabilization times during carbon fibre manufacture is presented in this work. The wet-spun precursor fibre is a specifically designed PAN co-polymer made up of acrylonitrile, methyl acrylate and 3 wt% itaconic acid. The residence or stabilization times in the oxidation ovens are varied from 32, 64 and 96 min, enabling investigation of the impact upon microstructure upon tensile and compressive properties. Using a continuous pilot scale carbonization line for faster cyclization and dehydrogenation, the precursor fibres exhibited lower oxygen uptake contributing to the formation of a less dense and more amorphous carbon fibre. Synchrotron based SAXS-WAXS characterisation and Raman spectroscopy of the carbon fibre microstructure displays lower orientation and crystallinity, with higher void concentration. This led to lower electrical conductivity, lower tensile strength (19 %) but higher compressive strength (27 %) when reducing stabilisation times from 96 to 32 min.

Enhancing interfacial locking of the CF and PBPESK resin by in-situ electrochemical deposition of MOF nanoparticles

The interfacial bonding of carbon fiber reinforced polymer composites plays a critical role in the overall performance of the composites. Poor interfacial bonding leads to catastrophic damage of composites when subjected to external loads. In this study, three-dimensional (3D) NH2-UiO-66 nanoparticles in-situ synthesis on the carbon fiber (CF) surface using an electrochemical method was achieved facilely and efficiently to enhance the interfacial adhesion of CF/PBPESK composites. The influence of incorporating 3D NH2-UiO-66 nanoparticles into the interphase on the interfacial and mechanical properties of carbon fiber reinforced composites was systematically investigated. The NH2-UiO-66 nanoparticles significantly increased the carbon fibers surface energy. The flexural, interlaminar shear and interfacial shear strength of the N–CF–6min/PBPESK composite were improved by 19 %, 31 %, and 93 %, respectively, compared to the D-CF/PBPESK composite. Furthermore, the interfacial failure mechanism of the composites was investigated. This approach offered a simple and efficient strategy for the in-situ synthesis of interfacial phase characterized by robust mechanical locking effects.

Prediction of Tensile Properties of Natural Fiber Reinforced PP Hybrid Composites by Facca-Kortschot-Yan (FKY) and Palsule Equations

Abstract Natural fiber reinforced polymer hybrid composites are advanced materials for commercial and engineering applications. Rule of hybrid mixtures has been applied to develop Facca-Kortschot-Yan (FKY) Equation and Palsule equation for predicting tensile strength and modulus of these hybrid polymer composites. This study predicts the values of tensile strength and modulus of a few natural fibers reinforced polypropylene hybrid composites by these two equations and compares them with the reported experimental values.

A novel method for through-thickness reinforcement of laminated composites using discrete micro-polarization-induced fiber injection (DMFI) approach

Conventional through-thickness reinforcement methods for laminated composites, such as Z-pin, encounter issues with in-plane property degradation and complex fabrication processes. To achieve rapid and low-damage reinforcement, a novel approach using short-chopped carbon fibers (SCFs) to form a micron-diameter interlaminate structure has been proposed. This method employs a discrete micro-polarization-induced fiber injection (DMFI) technique, where polarized SCFs are electrostatically oriented and injected at high speeds into pre-formed holes in the laminates. The insertion process of SCFs was thoroughly investigated, with optimal interlaminate conditions determined using high-speed cameras and other equipment. The toughening mechanism of SCFs was explored through various characterization methods, including metallurgical microscopy. This innovative method offers several advantages over the traditional Z-pin reinforced method. Notably, present method eliminates the need for prefabrication of Z-pins and fully leverages the excellent mechanical properties of individual carbon fiber in short length. It provides superior interlaminar mechanical properties, achieving a 392% improvement compared to the control group and a 15% improvement compared to 0.1 mm Z-pin reinforcement at the same insertion volume fraction. Additionally, it has minimal impact on the in-plane properties of the laminates, with only a 3.6% reduction in tensile strength and a 4.1% reduction in compression strength. Furthermore, it is environmentally friendly, allowing for the recycling and reuse of waste SCFs.

Cryogenic mechanical performance and gas-barrier property of epoxy resins modified with multi-walled carbon nanotubes

Type V linerless hydrogen storage vessels made of all-composite face the challenges of cryogenic mechanical failure and hydrogen leakage of composites. The cryogenic mechanical performance and gas-barrier property of the carbon fiber reinforced polymer for Type V vessels are largely determined by the epoxy matrix. Carbon nanotubes are widely used as polymer reinforcement material to enhance the cryogenic mechanical performance and gas-barrier property of epoxy resins. In this work, multi-walled carbon nanotubes (MWCNTs) were dispersed into epoxy resins to prepare MWCNTs-modified epoxy resins. The cryogenic mechanical performance, gas-barrier and thermal properties of the modified resin were then investigated. The experimental findings revealed a 34.34% reduction in the gas permeability coefficient for the nanocomposites containing 0.9 wt% MWCNTs compared with the epoxy matrix. The tensile strength and failure strain at cryogenic temperature (77 K) experienced enhancements of 26.99% and 41.53%, respectively. In addition, the thermal stability and glass transition temperature of the modified resin were improved. As a result, the MWCNTs-modified epoxy resin exhibits improved gas-barrier property in addition to excellent cryogenic mechanical performance, making it ideal for manufacturing Type V linerless hydrogen storage vessels.

Effect of Mercerization on the Properties of Cellulose Fiber and Cellulose Hydrogel Extracted from Pineapple Leaf Fiber

AbstractThis study investigated the effects of alkaline treatment on the pineapple leaf fiber (PALF) cellulose extraction and the properties of cellulose hydrogel. PALF was treated with different concentrations of sodium hydroxide (NaOH) (2 to 10 wt %) and at room temperature (RT) and 80 °C. Then, extracted cellulose was then dissolved in N,N’‐dimethyl acetamide (DMAc)/lithium chloride (LiCl) solvent system and formed into hydrogel by phase inversion method. The Fourier transform infrared spectra shows the peak disappearance at 1606 cm−1 proves that lignin was removed starting from 6 and 4 wt % NaOH at RT and 80 °C, respectively. Higher NaOH concentrations treatment increased thermal stability and the crystallinity (71 to 79 %) of the fibers. Higher NaOH concentration and treatment temperature enhanced cellulose extraction from PALF, leading to more physical crosslinking during hydrogel formation. High amount of cellulose extracted decreased the hydrogel's swelling equilibrium and increased the gel fraction. The highest transmittance (87.8 %) and the lowest intensity of absorbance (at 280 nm corresponding to lignin) were obtained by the hydrogel prepared with PALF treated with 8 wt % NaOH at 80 °C. Clearly, this research findings provide new insights into optimizing cellulose extraction using alkaline treatment specifically for cellulose hydrogel formation.

Evaluation of the relationship between the number of surface and internal defects and stress in inorganic fibers

To better utilize the mechanical properties of ceramics fibers, it is very important to understand the ceramics fiber distribution. The strength distribution of ceramics fibers is strongly dependent on defects that are present in or on the surface of the material. When the defects are large, the location of the defects is identified by observing the fracture surface, and the strength of the material is analyzed based on the results. However, in recent years, defects in high-strength ceramics such as carbon fibers have become so small that it is very difficult to analyze the location of such defects. To overcome this problem, a defect analysis method has been developed based on the observation that the tensile strength of fibers decreases when tensile tests are performed in liquids. In this study, a new model that considers both surface and internal defects of fibers was introduced into this analysis method, and the newly developed method was applied to quantitatively separate surface and internal defects of polyacrylonitrile-based fibers, pitch-based carbon fibers, SiC fibers, and glass fibers in air, water, and organic solvents. The number of internal and external defects was expressed as a function of stress. Based on the number of defects, the influence of surface defects was significant for glass fibers, polyacrylonitrile-based carbon fibers, silicon carbide fibers, and pitch-based carbon fibers, in that order. This method is useful for analyses of surface defects in fibers.

Thermal Performance Of Termite Mold Bricks Reinforced With Empty Fruit Bunch Spikelet And Coconut Fibers

The use of natural fibers to enhance the thermal properties of earth bricks has become increasingly popular. This study investigates the thermal performance of termite mold soil (TMS) reinforced with two types of fibers: coconut fibers (CF) and empty fruit bunch spikelet fibers (EFBSF). Various fiber compositions (0%, 0.5%, 1%, 1.5%, 2%, and 2.5%) were combined with sodium hydroxide (NaOH) treatments at concentrations of 1%, 2%, 3%, and 4%. Laboratory results reveal that TMS exhibits promising physical properties, including a moisture content of 23.64%, a maximum dry density of 1.63 g/cm³, and a plasticity index of 20%, indicating its structural stability and suitability for earth block production. The study also analyzes the chemical properties of EFBSF and CF fibers, noting that CF has a higher holocellulose content (88.0%) compared to EFBSF (33.5%), which impacts moisture retention and structural integrity. Thermal analysis demonstrates that incorporating these natural fibers significantly enhances the thermal performance of TMS. With a 2.5% fiber content, CF reduces thermal effusivity from 1771.43 J/m²Ks^1/2 to 1079.39 J/m²Ks^1/2 and thermal conductivity from 0.86 W/mK to 0.38 W/mK, making it particularly effective in improving insulation in hot conditions. EFBSF also lowers thermal effusivity and conductivity, but to a lesser extent than CF. Additionally, the presence of these fibers reduces volumetric calorific capacity, with CF showing a more pronounced effect. Overall, TMS reinforced with coconut fibers, especially at 1% NaOH and 2.5% fiber content, offers the best thermal performance, suggesting its potential for sustainable construction. This research promotes the use of locally sourced, natural fibers in earth block manufacturing, contributing to the development of more energy-efficient and environmentally friendly building materials.

Antibacterial, antioxidant and barrier properties of clay-doped electrospun fibers

Nowadays, packaging technologies have been extensively developed, including active and intelligent packages able to promote quality, safety, and the product shelf life. At this purpose, the aim of the study was focused on the design and development of polyvinyl alcohol-based nanofibers doped with two natural clays, montmorillonite or clinoptilolite, and loaded with chlorogenic acid, as nanofibrous membranes to control microbial contamination and oxidative state upon direct contact. The results showed that the 1 % w/w clay doping was the optimal concentration to obtain continuous and uniform nanofibers. In addition, chlorogenic acid loading (5 % w/w) into the nanofibers did not change the systems morphology, resulting in a chlorogenic acid sustained release, achieving 100 % within 24 h for all the systems with enhanced antioxidant and antimicrobial activities. Depending on their structure, the presence of the clays mineral was able to affect the aqueous vapor permeability. These results suggested the promising applications of the clay doped polyvinyl alcohol-based nanofibrous membranes as smart advanced material able to control microbial contamination and oxidative degradation to be used in biomedical field or as active packaging.

Extraction technology determines the properties of bamboo shoots dietary fiber concentrate and its application in chicken mince gels: Systematic analysis

This study investigated how physical, chemical, and enzymatic extraction technologies affected the physicochemical properties of bamboo shoot insoluble dietary fiber (IDF). Additionally, the effects of IDF extracted by these techniques on the gel properties, water retention, microstructure, and digestibility of chicken mince gels were evaluated. Results showed that IDFs extracted by physical (P-IDF), chemical (C-IDF), and enzymatic (E-IDF) exhibited a typical cellulose polysaccharide structure and strong water and oil retention capabilities, with the highest values reaching 14.18 g/g and 6.74 g/g, respectively. Compared to P-IDF, C-IDF and E-IDF displayed a rougher porous structure and stronger adsorption capacities for glucose (409.91 mg/g and 604.95 mg/g), cholesterol (54.46 mg/g and 64.06 mg/g), sodium cholate, and nitrite. The addition of IDF improved the water retention, water stability, texture, and rheological properties of chicken mince gels, and had no negative effect on the digestion of chicken mince proteins. On the one hand, the hydrophilic groups exposed in IDF absorb water and fill the gel networks, reducing the formation of water channels in the gel and improving water stability. Furthermore, the hydrophilic groups on the glucose unit that makes up the IDF interacts with the proteins through the hydrogen bond and the transformation of protein β-structure to α-structure, promoting the formation of gel network structure and improving gel texture and rheological properties. E-IDF and C-IDF showed better overall gel performances, but E-IDF had better dry matter digestibility, protein digestibility, and gastrointestinal digestive effects. Therefore, IDF prepared by enzymatic hydrolysis is more suitable for chicken mince processing.

Robust and washable silk fiber-based electrochemical biosensor for high-performance sensing of hydrogen peroxide

Wearable electronics, especially fiber-based biosensors, show promise in large-scale production and reusability compared with conventional wafer-based electronics. However, it is challenging to use wearable electronics, with less intensity and non-wash ability, to produce fiber-based biosensors for textiles. Here, a robust and washable Prussian blue (PB)-functionalized silk fiber (PB-SF) flexible electrode is reported. Modified cyanotype is successfully employed to immobilize PB nanoparticles (∼18.32 nm) onto silk fibers for hydrogen peroxide (H2O2) detection. The intrinsic mechanical properties of silk fibers are well maintained with slight increases in stress (∼10%) and strain (∼16%). Furthermore, the PB-SF electrode displays good electrochemical H2O2 sensing performance with sensitivity of 716.54 μA/mM·cm2, a linear range of 0.01∼0.6 mM and a low detection limit of 10 μM (S/N=3). Notably, the hybrid PB-SF electrode adapts to mechanical deformations with a series of angles and the electrical signals are not compromised obviously even after 100 home laundry washing cycles. PB modified silk fibers is simple, easy-operating and cost-effective electrode that is suitable for large-scale production as it can be integrated onto e-textiles through typical textile processing methods.

Evaluation of mechanical properties of natural fiber based polymer composite

Natural fiber based polymer composites are eco-friendly alternatives to synthetic materials, with greater mechanical properties, biodegradability, availability, ease of access, and affordability. Jute fiber is widely recognized as one of the most important and beneficial natural fibers due to its strength, durability, and biodegradability. In this study, the jute composite is designed and fabricated using a 5-layer jute and epoxy resin, utilizing the manual hand lay-up technique. The combination of 52.5 % jute and 47.5 % of epoxy resin and harder is found optimized to achieve the goals of improving the tensile strength and flexural strength, reducing the cost of epoxy resin, and promoting eco-friendliness and sustainability. Tensile testing was performed on a universal testing machine, while flexural testing was done with a three-point bending test. Experimentally, the composites reinforced with jute and epoxy resin were capable of achieving the required levels of tensile strength (42.91 MPa) and bending strength (69.30 MPa). To validate and visualize specimens, numerical analysis was performed on the ABAQUS simulation software. The numerical simulation utilized ASTM D3039 and ASTM D7264 as the specified requirements for tensile and flexural behavior. For validation, these tensile and flexural test results were then numerically analyzed and compared to the experimental data. Finally, composite design, fabrication, and optimization can improve mechanical properties, reduce composite weight, lower resin cost, and increase sustainability. The proposed design and composition can be implemented to achieve lightweight properties in various applications, such as car components, door handle sheets, bicycle seat backs, and luggage covers.

Ablative property and mechanism of pitch-based carbon fiber modified C/C composites with high thermal conductivity

The novel C/C composites with thermal transport function were prepared using the mesophase-pitch carbon fibers (CFMP) as the thermal diffusion channels. The introduction of CFMP greatly improved the microstructure, thermal properties, and ablative resistance of the C/C composites. During the graphitization process, compared with PAN fibers (CFPAN), CFMP was more likely to be graphitized to form a highly ordered three-dimensional graphite structure. The highly organized microcrystalline structure of CFMP resulted in a tight interface with PyC that lessened the likelihood of flaws and cracks during graphitization. CFMP, which acted as a thermal conduction skeleton, significantly improved the thermal conductivity of C/C composites. After 3000 °C HTT, the thermal conductivity of C/C-3000-Z composites was increased to 51.70 and 225.02 W/(m K) in the XY and Z planes, respectively. During the ablation process, C/C-3000-Z specimen exhibited a lower temperature gradient and less thermal stress owing to the outstanding thermal properties and fewer defects. After 30 s ablation, the temperature difference of surface and backside was only 495.9 °C, and the mass and linear ablation rates were 0.3 μm/s and 0.9 mg/s, respectively.

Stress-strain behaviour of pre-damaged concrete confined with natural fibre reinforced polymer

In recent years, using environmentally friendly construction materials has become a new trend in structural engineering. This research presents the application of natural fibre reinforced polymer (NFRP) composites for repairing damaged structural concrete members. The compressive behaviour of pre-peak damaged concrete confined with two types of NFRP composites was investigated. The tensile properties of jute fibre reinforced polymer (JFRP) and sisal fibre reinforced polymer (SFRP) were examined and compared with those of carbon fibre reinforced polymer (CFRP) using coupon tests. Subsequently, a series of pre-damaged concrete cylinders, confined with JFRP, SFRP, and CFRP, were subjected to uniaxial compression tests. The results showed that JFRP and SFRP are effective in providing confinement to pre-peak damaged concrete. The strength and ductility of pre-peak damaged concrete confined with NFRP increased with the number of NFRP layers. The cost-effectiveness of FRP-confined concrete was also evaluated, with JFRP being the most economically efficient. The eco-strength efficiency (ESE), defined as the increased compressive strength per unit of CO2 emissions, shows that JFRP is the most effective. This highlights JFRP's potential for sustainable construction. Finally, the compressive strength models were proposed. The models demonstrate improved accuracy in predicting the peak compressive strength of pre-peak damaged concrete confined with NFRP compared to existing models.

Comparisons of reported and predicted tensile properties of natural fiber reinforced HDPE composites

Comparisons of reported and predicted tensile properties of natural fiber reinforced HDPE composites

Interfacial crystallization behavior and properties of T1100-grade carbon fiber reinforced PEEK composites

As a semi-crystalline resin, the crystallization behavior of Polyether ether ketone at the interface between carbon fiber and resin matrix profoundly affects the interfacial properties of carbon fiber-reinforced PEEK composite. Therefore, the research on the interfacial crystallization behavior of CF/PEEK composite is of great significance. Aiming at Chinese-made T1100-grade carbon fiber and PEEK resin matrix, the effects of cooling rate and sizing agent on the interfacial crystallization behavior of T1100-grade carbon fiber/PEEK were studied by POM and DSC, and the IFSS was tested by microdebond. The experimental results show that the increase of the cooling rate and the removal of the sizing agent can improve the nucleation ability of PEEK and promote the interfacial crystallization of PEEK. PEEK starts to form transcrystallization, when the nucleus density is increased to about 0.07/μm. The interfacial crystallization behavior has an effect on the interfacial properties. The IFSS increases with increasing cooling rate and removal of sizing agent.

Effect of tungsten carbide interface decoration on thermal and mechanical properties of carbon fiber reinforced copper matrix composites

The use of carbon fiber (CF)/copper (Cu) composites as thermal management materials shows significant promise. However, inadequate interface bonding hinders their thermal properties. This study introduces a novel method to create tungsten carbide–coated CFs (CF(WC)) using the molten salt method. These coated fibers are then used to develop a CF(WC)/Cu composite through vacuum hot-pressing sintering. Results reveal that the WC coating, formed at 1100 ℃ for 60min with a tungsten trioxide/CF molar ratio of 1/10, is continuous, crack-free, and has an appropriate thickness. The WC coating facilitates excellent interface bonding between Cu and CF, thus effectively improving the initial poor interface bonding. With similar 50% fiber content, the CF(WC)/Cu composite exhibits better thermal and mechanical properties than the CF/Cu composite. The in-plane direction thermal conductivity and bending strength of the CF(WC)/Cu composite are 398.7 ± 8.1Wm−1 K−1 and 195.3 ± 6.2MPa, which are 35.3% and 90.4% higher, respectively, than those of the CF/Cu composite. Additionally, the in-plane direction coefficient of thermal expansion is 6.5 ± 0.3 × 10−6 K−1, representing a notable reduction of 37.5%. These exceptional properties, coupled with the simplicity and efficacy of the preparation process, offer valuable insights for the advancement of carbon/Cu thermal management materials.

Study on resistance of basalt fiber reinforced concrete to sulfate erosion after cryogenic freeze-thaw cycles

This study aims to investigate the mechanical properties of concrete structures, such as liquefied natural gas (LNG) storage tanks, subjected to the effects of cryogenic freeze-thaw cycles and erosive environmental conditions. Mechanical properties of basalt fiber reinforced concrete (BFRC) with normal temperature (25 °C) and different temperature gradients (25 °C ∼ -80 °C, 25 °C ∼ -160 °C), fiber content (0 %, 0.1 %, 0.2 %), and sulfate erosion days (0, 60, 120) were determined. The morphology of the eroded specimens was examined, and the microstructural characteristics were investigated by scanning electron microscope (SEM). The findings revealed that the introduction of basalt fiber (BF) in the concrete significantly changes the failure mode following sulfate erosion, causing specimens to fail by ductile failure rather than brittle failure. Moreover, the mechanical properties of concrete specimens decreased significantly with increasing temperature gradients of freeze-thaw cycles. Under non-erosive conditions, the compressive strength of plain concrete after undergoing freeze-thaw cycles from 25 °C to -160 °C decreased by 22.4 % compared to plain concrete that did not undergo freeze-thaw cycles, and the tensile strength decreased by 32.5 %. Adding fibers increased the mechanical properties of specimens. Specially, after undergoing freeze-thaw cycles from 25 °C to -160 °C and being subjected to 120 days of sulfate erosion, compared with plain concrete, the compressive strength of specimens with 0.2 % fiber content increased by 20.6 %, the tensile strength increased by 37.8 %, while also increasing flexural toughness. In addition, the sulfate erosion days also had a considerable impact on the deterioration of the mechanical properties of specimens. Specially, after undergoing freeze-thaw cycles from 25 °C to -80 °C and being subjected to 120 days of erosion, the eroded specimen with 0.1 % fiber content, the compressive strength decreased by 10.9 %, the tensile strength decreased by 11.6 % compared to specimens that were not eroded, while also decreasing flexural toughness. Combined with the experimental results, the strength deterioration models of BFRC related to the sulfate erosion days and BF content were proposed at 25 °C, after freeze-thaw cycles from 25 °C to -80 °C, and after freeze-thaw cycles from 25 °C to -160 °C. The aim is to provide some data reference for the development and application of BFRC in cryogenic environments.

Particle size of straw and gelation of pectin influence gastric mixing and emptying in pigs

Physicochemical properties of fibres can strongly impact gastric processes such as emptying and sieving. This study evaluated the influence of particle size of insoluble fibres, and gelation of soluble fibres when added to insoluble fibres, on gastric emptying of digesta phases from the proximal and distal stomach of pigs. Twenty-four boars (51.6 ± 4.90 kg) were assigned to one of four diets, containing either 150 g/kg coarse or finely milled wheat straw (median particle area of 5.4 vs. 0.3 mm2), or 270 g/kg wheat bran without or with the addition of 100 g/kg low-methylated pectin. Tracers were used to quantify the mean retention time (MRT) of digesta liquids (Co-EDTA), fine solids (TiO2), and fibrous particles (Chromium-mordanted fibres). For all diets, digesta pH was lower in the distal stomach than in the proximal stomach (-1.1 to 2.1 units; P < 0.05). In the proximal stomach, particle size reduction of straw tended to decrease digesta pH (-0.8 units; P = 0.072), reduced the MRT of fine solids (-117 min; P = 0.009) and the separation between fine solids and liquids (-88 min; P = 0.030). When particle size of straw was reduced, the MRT of liquids was no longer greater in the proximal stomach compared with the distal stomach (P > 0.10), while in both regions, the MRT of fibrous particles (-213 to 238 min; P < 0.05) and the difference between fibrous particles and fine solids were reduced (-96 to 181 min; P < 0.05). Accordingly, sieving of nutrients, such as starch and non-starch polysaccharides (NSP) was reduced. In the proximal stomach, the greater water holding capacity (WHC) and resistance to deformation conferred by the addition of pectin decreased the MRT of fine solids (-138 min; P = 0.003), and fibrous particles (-227 min; P < 0.001), reducing the difference between fine solids and liquids (-148 min; P < 0.001), and between fibrous particles and fine solids (-89 min; P < 0.001). In the distal stomach, pectin addition reduced the MRT of fibrous particles (-203 min; P = 0.007), and the difference between fibrous particles and fine solids (-154 min; P < 0.001). Concomitantly, sieving of nutrients across stomach regions was reduced. In conclusion, particle size reduction of straw and pectin addition accelerated the emptying of fine and coarse solids, and reduced sieving of digesta phases and nutrients in the proximal and distal stomach of pigs.