| 1. |
- Arya, Mina, et al.
(författare)
-
Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes
- 2023
-
Ingår i: Polymers. - : Multidisciplinary Digital Publishing Institute (MDPI). - 2073-4360. ; 15:18
-
Tidskriftsartikel (refereegranskat)abstract
- The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers’ substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young’s modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials.
|
|
| 2. |
- Blinzler, Brina, 1987, et al.
(författare)
-
High performance/high rate composite processing with trapped rubber
- 2019
-
Ingår i: ICCM International Conferences on Composite Materials.
-
Konferensbidrag (refereegranskat)abstract
- Trapped rubber processing (TRP) is an autoclave alternative to achieving high pressures during polymer matrix composite processing, utilizing thermally induced volume change of a nearly incompressible material inside a closed cavity mould. Recent advances in material and computational technology have made this processing technique more attractive. Computer electronics research has led to the development of elastomers with relatively high thermal conductivity. In addition, recent advances in computer processing have opened the possibility to simulate complex thermomechanical processes with finite element analysis. In this study, the volumetric change and resulting pressure is captured via a series of experiments. These experiments are used to characterize the dynamic in situ change in temperature, the dynamic change in volume and the resulting real-time change in surface pressure at multiple locations throughout the sample. The material characterization includes an iterative testing and computational modelling framework where the design of experiments is fed by initial material models based on the linear coefficient of thermal expansion and then the characterization is improved by the experimental tests. The silicone rubber elastomer used in this initial study was chosen to be compatible with the cure cycle for Hexcel M21 epoxy prepreg system, due to the large amount of material and processing data available. The development of an accurate thermomechanical material model of nearly incompressible elastomeric polymers for use in advanced trapped rubber processing modelling will allow more design freedom with more advanced shapes and less risk of processing failure while maintaining the possibility for custom distributions of pressures and temperatures, therefore, high-quality consolidation during curing.
|
|
| 3. |
- Blinzler, Brina, 1987, et al.
(författare)
-
Integrated Computational Material Design for PMC Manufacturing with Trapped Rubber
- 2020
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 13:17
-
Tidskriftsartikel (refereegranskat)abstract
- As the use of continuous fiber polymer matrix composites expands into new fields, there is a growing need for more sustainable manufacturing processes. An integrated computational material design framework has been developed, which enables the design of tailored manufacturing systems for polymer matrix composite materials as a sustainable alternative to achieving high-quality components in high-rate production. Trapped rubber processing achieves high pressures during polymer matrix composite processing, utilizing the thermally induced volume change of a nearly incompressible material inside a closed cavity mold. In this interdisciplinary study, the structural analysis, material science and manufacturing engineering perspectives are all combined to determine the mold mechanics, and the manufacturing process in a cohesive and iterative design loop. This study performs the coupled thermo-mechanical analysis required to simulate the transients involved in composite manufacturing and the results are compared with a previously developed test method. The internal surface pressure and temperatures are computed, compared with the experimental results, and the resulting design process is simulated. Overall, this approach maintains high-quality consolidation during curing while allowing for the possibility for custom distributions of pressures and temperatures. This can lead to more sustainable manufacturing by reducing energy consumption and improving throughput.
|
|
| 4. |
- Blinzler, Brina, 1987, et al.
(författare)
-
TRAPPED RUBBER PROCESSING SIMULATION FOR HIGH PERFORMANCE / HIGH RATE PROCESSING
- 2019
-
Ingår i: SAMPE Europe Conference 2019 Nantes. - 9781713821212 ; , s. 893-
-
Konferensbidrag (refereegranskat)abstract
- Trapped rubber processing (TRP) is an autoclave alternative to achieving high pressures during processing, utilizing temperature induced change in volume of a hyperelastic material. Recent advances in material and computational technology have made this processing technique more attractive. Through detailed experimental characterization, a design tool has been developed. In addition, a method has been developed for this characterization process that can be used for other TRP materials. TRP allows more design freedom with more advanced shapes and less risk of processing failure while maintaining the possibility for custom distributions of pressures and temperatures, therefore, high-quality consolidation during curing is achieved.
|
|
| 5. |
- Cong, X., et al.
(författare)
-
Investigation of fire protection performance and mechanical properties of thin-ply bio-epoxy composites
- 2021
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 13:5, s. 1-13
-
Tidskriftsartikel (refereegranskat)abstract
- Hybrid composites composed of bio-based thin-ply carbon fibre prepreg and flame-retardant mats (E20MI) have been produced to investigate the effects of laminate design on their fire protection performance and mechanical properties. These flame-retardant mats rely primarily on expandable graphite, mineral wool and glass fibre to generate a thermal barrier that releases incom-bustible gasses and protects the underlying material. A flame retardant (FR) mat is incorporated into the carbon fibre bio-based polymeric laminate and the relationship between the fire protection properties and mechanical properties is investigated. Hybrid composite laminates containing FR mats either at the exterior surfaces or embedded 2-plies deep have been tested by the limited oxygen index (LOI), vertical burning test and cone calorimetry. The addition of the surface or embedded E20MI flame retardant mats resulted in an improvement from a base line of 33.1% to 47.5% and 45.8%, respectively. All laminates passed the vertical burning test standard of FAR 25.853. Cone calorimeter data revealed an increase in the time to ignition (TTI) for the hybrid composites containing the FR mat, while the peak of heat release rate (PHRR) and total heat release (TTR) were greatly reduced. Furthermore, the maximum average rate of heat emission (MARHE) values indicated that both composites with flame retardant mats had achieved the requirements of EN 45545-2. However, the tensile strengths of laminates with surface or embedded flame-retardant mats were reduced from 1215.94 MPa to 885.92 MPa and 975.48 MPa, respectively. Similarly, the bending strength was reduced from 836.41 MPa to 767.03 MPa and 811.36 MPa, respectively. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
|
|
| 6. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Elastomer Characterization Method for Trapped Rubber Processing
- 2020
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- The increasing high-volume demand for polymer matrix composites (PMCs) brings into focus the need for autoclave alternative processing. Trapped rubber processing (TRP) of PMCs is a method capable of achieving high pressures during polymer matrix composite processing by utilizing thermally induced volume change of a nearly incompressible material inside a closed cavity mold. Recent advances in rubber materials and computational technology have made this processing technique more attractive. Elastomers can be doped with nanoparticles to increase thermal conductivity and this can be further tailored for local variations in thermal conductivity for TRP. In addition, recent advances in computer processing allow for simulation of coupled thermomechanical processes for full part modeling. This study presents a method of experimentally characterizing prospective rubber materials. The experiments are designed to characterize the dynamic in situ change in temperature, the dynamic change in volume, and the resulting real-time change in surface pressure. The material characterization is specifically designed to minimize the number and difficulty of experimental tests while fully capturing the rubber behavior for the TRP scenario. The experimental characterization was developed to provide the necessary data for accurate thermomechanical material models of nearly incompressible elastomeric polymers for use in TRP virtual design and optimization.
|
|
| 7. |
- Khalili, Pooria, et al.
(författare)
-
Fabrication : Mechanical Testing and Structural Simulation of Regenerated Cellulose Fabric Elium(R) Thermoplastic Composite System
- 2021
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 13:17
-
Tidskriftsartikel (refereegranskat)abstract
- Regenerated cellulose fibres are an important part of the forest industry, and they can be used in the form of fabrics as reinforcement materials. Similar to the natural fibres (NFs), such as flax, hemp and jute, that are widely used in the automotive industry, these fibres possess good potential to be used for semi-structural applications. In this work, the mechanical properties of regenerated cellulose fabric-reinforced poly methyl methacrylate (PMMA) (Elium(R)) composite were investigated and compared with those of its natural fibre composite counterparts. The developed composite demonstrated higher tensile strength and ductility, as well as comparable flexural properties with those of NF-reinforced epoxy and Elium(R) composite systems, whereas the Young's modulus was lower. The glass transition temperature demonstrated a value competitive (107.7 degrees C) with that of other NF composites. Then, the behavior of the bio-composite under bending and loading was simulated, and a materials model was used to simulate the behavior of a car door panel in a flexural scenario. Modelling can contribute to predicting the structural behavior of the bio-based thermoplastic composite for secondary applications, which is the aim of this work. Finite element simulations were performed to assess the deflection and force transfer mechanism for the car door interior.
|
|
| 8. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Flammability, smoke, mechanical behaviours and morphology of flame retarded natural fibre/Elium® composite
- 2019
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 12:7
-
Tidskriftsartikel (refereegranskat)abstract
- The work involves fabrication of natural fibre/Elium® composites using resin infusion technique. The jute fabrics were treated using phosphorus-carbon based flame retardant (FR) agent, a phosphonate solution and graphene nano-platelet (GnP), followed by resin infusion, to produce FR and graphene-based composites. The properties of these composites were compared with those of the Control (jute fabric/Elium®). As obtained from the cone calorimeter and Fourier transform infrared spectroscopy, the peak heat release rate reduced significantly after the FR and GnP treatments of fabrics whereas total smoke release and quantity of carbon monoxide increased with the incorporation of FR. The addition of GnP had almost no effect on carbon monoxide and carbon dioxide yield. Dynamic mechanical analysis demonstrated that coating jute fabrics with GnP particles led to an enhanced glass transition temperature by 14%. Scanning electron microscopy showed fibre pull-out locations in the tensile fracture surface of the laminates after incorporation of both fillers, which resulted in reduced tensile properties. © 2019 by the authors.
|
|
| 9. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Fully Biodegradable Composites: Thermal, Flammability, Moisture Absorption and Mechanical Properties of Natural Fibre-Reinforced Composites with Nano-Hydroxyapatite
- 2019
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 12:7
-
Tidskriftsartikel (refereegranskat)abstract
- Natural fibre-reinforced poly(lactic acid) (PLA) laminates were prepared by a conventional film stacking method from PLA films and natural fabrics with a cross ply layup of [0/90/0/90/0/90], followed by hot compression. Natural fibre (NF) nano-hydroxyapatite (nHA) filled composites were produced by the same manufacturing technique with matrix films that had varying concentrations of nHA in the PLA. Their flammability, thermal, moisture absorption and mechanical properties were analysed in terms of the amount of nHA. The flame behavior of neat PLA and composites evaluated by the UL-94 test demonstrated that only the composite containing the highest quantity of nHA (i.e., 40 wt% nHA in matrix) was found to achieve an FH-1 rating and exhibited no recorded burn rate, whereas other composites obtained only an FH-3. The thermal degradation temperature and mass residue were also observed, via thermogravimetric analysis, to increase when increasing concentrations of nHA were added to the NF composite. The tensile strength, tensile modulus and flexural modulus of the neat resin were found to increase significantly with the introduction of flax fibre. Conversely, moisture absorption was found to increase and mechanical properties to decrease with both the presence of NF and increasing concentrations of nHA, and subsequent mechanical properties experienced an obvious reduction.
|
|
| 10. |
- Khalili, Pooria, et al.
(författare)
-
Impregnation behaviour of regenerated cellulose fabric Elium® composite : Experiment, simulation and analytical solution
- 2021
-
Ingår i: Journal of Materials Research and Technology. - : Elsevier Editora Ltda. - 2238-7854. ; 10, s. 66-73
-
Tidskriftsartikel (refereegranskat)abstract
- Filling time and volume fill prediction of long and complex parts produced using the method of resin infusion is of prominent importance. Fibre volume fraction, reinforcement type and composite laminate thickness significantly affect the manufacturing behaviour. It is crucial to have an estimate of fabrication parameters such as filling time. The PAM-RTM (resin transfer moulding) commercial software package makes it possible to characterize the production parameters in connection with lab scale experiments. In this work, simulation tools demonstrate an accurate prediction of the resin infusion process of pulp-based fabrics and characterization of the dynamic phenomena are verified using the analytical solution for a simple part. The accurate prediction for fabrication of pulp-based fabric Elium® composite demonstrated here can be beneficial for scaling up the composite part size and production speed. The filling time was accurately predicted until 270 s for the volume fill of 10-100% using the software tool and analytical solution. This proves the rayon fabric processing capabilities as a reinforcement for industry related projects and opens for the possibility of infusion process optimization.
|
|
| 11. |
- Khalili, Pooria, et al.
(författare)
-
Mechanical Properties of Bio-Based Sandwich Composites Containing Recycled Polymer Textiles
- 2023
-
Ingår i: Polymers. - 2073-4360. ; 15:18, s. 1-14
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, sandwich composites were produced by compression moulding techniques, and they consisted of regenerated cellulose fabric (rayon) and bio-based polypropylene (PP) to form facings, while virgin and recycled polyamide (PA) textiles were used as core materials. To compare the mechanical performance between sandwich composites and typical composite designs, a control composite was produced to deliver the same weight and fiber mass fraction from rayon and PP. To evaluate the influence of recycled textile on the mechanical properties of the composites, a series of flexural, low velocity impact (LVI) and tensile tests were performed. It was found that the incorporation of thicker PA textile enhanced the bending stiffness by two times and the peak flexural force by 70% as compared to those of control. Substitution of a layer of recycled textile for two layers of rayon provided a good level of impact energy absorption capacity (~28 J) and maximum force (~4893–5229 N). The tensile strength of the four sandwich composites was reported to be in the range of 34.20 MPa and 46.80 MPa. This value was 91.90 for the control composite. The 2D cross-section slices of the composite specimens did not show any evidence of fiber tow debonding, fiber bundle splitting, or delamination.
|
|
| 12. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Ramie fabric Elium® composites with flame retardant coating : Flammability, smoke, viscoelastic and mechanical properties
- 2020
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier Ltd. - 1359-835X .- 1878-5840. ; 137
-
Tidskriftsartikel (refereegranskat)abstract
- This investigation studied the utilization of intumescent thermal resistive mats to provide surface protection to the core natural fibre-reinforced Elium® composite structural integrity. The intumescent mats contained flame retardant (FR) i.e. expandable graphite (EG) with four different expansion ratios and alumina trihydrate (ATH). All natural fibre thermoplastic composites were fabricated using a resin infusion technique. The impact of char thickness and chemical compositions on the flammability and smoke properties was investigated. It was found that surface protection significantly reduced the peak heat release rate, total smoke release, smoke extinction area and CO2 yield, and substantially enhanced UL-94 rating, time to ignition and residual char network, depending on the EG exfoliation ratio, ATH and mineral wool fibre. The glass transition temperature increased for the FR composites containing EG with lower expansion ratio. Inclusion of intumescent mats increased the strength of the composites while it had a negative effect on the modulus.
|
|
| 13. |
- Khalili, Pooria, et al.
(författare)
-
Regenerated cellulose fabric reinforced bio-based polypropylene sandwich composites: fabrication, mechanical performance and analytical modelling
- 2023
-
Ingår i: Journal of Materials Research and Technology. - : Elsevier BV. - 2238-7854. ; 22, s. 3423-3435
-
Tidskriftsartikel (refereegranskat)abstract
- Sandwich composites were fabricated successfully with the balsa wood as core material and regenerated cellulose fabric bio-based polypropylene (PP) composite skins. The regenerated cellulose fabric PP composites were produced using two different methods: the conventional stacking lay-up and directly using PP pellets. Sandwich composites were made using the hot press equipment with the customized mold. The sandwich composite system and bio-composite laminate were designed to achieve very close weight to compare the key mechanical properties that each design can bear. It was evidenced from the experimental results that 416% increase in the bending load bearing property of the part can be obtained when sandwich structure was used. These experimental results were in close agreement with one of the analytical modelling utilised. The drop weight impact test results demonstrated that the sandwich specimen is capable of withstanding more than 6 kN load and absorbing the impact energy of 28.37 J.
|
|
| 14. |
- Uusi-Tarkka, Eija-Katriina, et al.
(författare)
-
Mechanical and Thermal Properties of Wood-Fiber-Based All-Cellulose Composites and Cellulose-Polypropylene Biocomposites
- 2023
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 15:3
-
Tidskriftsartikel (refereegranskat)abstract
- This article explores wood-fiber-based fabrics containing Lyocell yarn in the warp and Spinnova–Lyocell (60%/40%) yarn in the weft, which are used to form unidirectional all-cellulose composites (ACC) through partial dilution in a NaOH–urea solution. The aim is to investigate the role of the yarn orientation in composites, which was conducted by measuring the tensile properties in both the 0° and 90° directions. As a reference, thermoplastic biocomposites were prepared from the same fabrics, with biobased polypropylene (PP) as the matrix. We also compared the mechanical and thermal properties of the ACC and PP biocomposites. The following experiments were carried out: tensile test, TGA, DSC, DMA, water absorption test and SEM. The study found no significant difference in tensile strength regarding the Spinnova–Lyocell orientation between ACC and PP biocomposites, while the composite tensile strength was clearly higher in the warp (Lyocell) direction for both composite variants. Elongation at break doubled in ACC in the Lyocell direction compared with the other samples. Thermal analysis showed that mass reduction started at a lower temperature for ACC, but the thermal stability was higher compared with the PP biocomposites. Maximum thermal degradation temperature was measured as being 352 °C for ACC and 466 °C for neat PP, and the PP biocomposites had two peaks in the same temperature range (340–474 °C) as ACC and neat PP combined. ACCs absorbed 93% of their own dry weight in water in just one hour, whereas the PP biocomposites BC2 and BC4 absorbed only 10% and 6%, respectively. The study highlights the different properties of ACC and PP reference biocomposites that could lead to further development and research of commercial applications for ACC.
|
|
