scholarly journals Thermoplastic Elastomer Biocomposites Filled with Cereal Straw Fibers Obtained with Different Processing Methods—Preparation and Properties

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 641 ◽  
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Fiber ◽  
Reference Sample ◽  
Thermoplastic Elastomer ◽  
Short Fiber ◽  
Thermoplastic Elastomers ◽  
Polymer Chains ◽  
Injection Molding Process ◽  
Molding Process ◽  
Crop Waste ◽  
Processing Techniques

This work is focused on thermoplastic elastomers composites (TPEs) reinforced with straw. Crop waste with different particle size was used as a filler of ethylene-octene rubber (EOR). Application of cheap and renewable natural fiber like straw into a TPE medium is not fully recognized and explored. The effect of fiber orientation induced by two processing techniques on the different mechanical properties of composites was investigated. Microscopic images were used to present the tested straw fractions and observe the arrangement and dispersion of fibers in the polymer matrix. It was found that the usage of an injection molding process allowed for the forming of a more homogenous dispersion of short fiber particles in the elastomer matrix. An oriented straw filler and polymer chains resulted in the improved mechanical strength of the whole system as evidenced by the obtained values of tensile strength almost two times higher for injected composites. In addition, all composites showed very good resistance to thermo-oxidative aging, where the aging factor oscillated within the limits of one, regardless of the processing method and the amount of bioadditive used. On the other hand, vulcanized composites were characterized by greater tear resistance, for which Fmit values increased by up to 600% compared to the reference sample.

scholarly journals Performance Evaluation of Composite from Recycled Polypropylene Reinforced with Mengkuang Leaf Fiber

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 97 ◽  
Author(s):  
Mohamad Zaki Abdullah ◽  
Nasrul Haziq Che Aslan
Keyword(s):  
Natural Fiber ◽  
Alkaline Treatment ◽  
Short Fiber ◽  
Injection Molding Process ◽  
Potential Candidate ◽  
Molding Process ◽  
Plastic Recycling ◽  
Recycled Polypropylene ◽  
The Impact ◽  
Leaf Fiber

Due to environmental concerns, plastic recycling and natural fiber composites have been given more attention lately. In Malaysia, mengkuang leaf fiber (MLF) has been identified as a potential candidate to be used as a reinforcing fiber. The combination of recycled polypropylene (r-PP) and MLF could result in an inexpensive and sustainable composite. However, the mechanical properties of this composite have not been fully studied. The aim of this work was to evaluate tensile, flexural and impact properties of r-PP/MLF composites with and without sodium hydroxide (NaOH) treatment and maleic anhydride-grafted polypropylene (MAPP). The composite consisted of 60 wt.% of r-PP and 40 wt.% of MLF. The composite was compounded by twin-screw extruder and test specimens were fabricated using an injection molding process. Generally, the tensile and flexural properties showed improvements, especially those with MAPP and alkaline treatment, compared to neat r-PP. Improvements in tensile strength and modulus of approximately 28% and 224% were achieved for r-PP/Treated MLF/MAPP composite respectively. However, an adverse effect was observed in the impact strength of the composite, which was expected due to the nature of short fiber employed in this work.

Prediction of Elastic Modulus of Glass Short Fiber/Wood Powder/Polypropylene Hybrid Composites

2013 ◽  
Author(s):  
Ying Yu ◽  
Manabu Nomura ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Hybrid Composites ◽  
Length Distribution ◽  
Wood Particle ◽  
Short Fiber ◽  
Injection Molding Process ◽  
Orientation Factor ◽  
Wood Powder ◽  
Molding Process

Recent years, thermoplastics incorporated with particulate fillers have been gained high interests. To improve the mechanical properties of the natural particle reinforced polymer plastics, hybrid structure has been applied on the composite combining natural particle with stronger synthetic fibers. However, the reinforcing mechanism of the hybrid composite is quite complicated. Experiments on it may become time consuming and cost prohibitive. Therefore, researchers are interested in studying variable models to predict the elastic properties of the composites. In this study, glass short fiber/wood particle/pp hybrid composites were prepared by injection molding process at a fixed reinforcement to matrix ratio of 51:49. 4 kinds of hybrid specimens with glass fiber/wood particle ratios of 41:10, 31:20, 21:30 and 11:40 were fabricated. The effect of hybridization content on the mechanical properties of the composites was evaluated based on tensile test. Theoretically, the elastic modulus of hybrid composites was predicted by using the rule of hybrid mixtures (RoHM) equation and classical lamination theory (CLT) and the accuracy of the two estimation models has been discussed. Results showed that it can be considered the hybridization of wood powder into glass/PP composite could contribute to a similar high elastic modulus with high green degree. On the other hand, the fiber orientation factor, fiber length distribution factor, powder dispersion factor were very important factors and need to be considered in the prediction model.

Analysis of Additive Alignment in a 90∘ Elbow Channel

2020 ◽  
Vol 28 (04) ◽  
pp. 2050032
Author(s):  
Hoang Minh Khoa Nguyen ◽  
Dong-Wook Oh
Keyword(s):  
Flow Visualization ◽  
Fiber Type ◽  
Weight Ratio ◽  
High Strength ◽  
Short Fiber ◽  
Industrial Applications ◽  
Injection Molding Process ◽  
Molding Process ◽  
Corner Region ◽  
Liquid Polymer

Short-fiber reinforced polymer composites have been widely used in industrial applications due to high strength-to-weight ratio, versatile manufacturing process, and etc. The alignment of fiber type additives plays an important role in the mechanical properties of a composite material. In this paper, an injection molding process was imitated with a liquid polymer composite flow inside a [Formula: see text] elbow channel. We performed a flow visualization experiment and analyzed the additive alignment of carbon fiber flowing in the polydimethylsiloxane (PDMS) medium. By analyzing the flow visualization images, the angle changes at the corner region of the elbow channel were calculated. At the corner region, the change of passage direction leads to the change of fiber orientation. It was observed that near to the convex region, fibers have angle change values larger than the fibers traveling near to the concave region.

A Finite Element Based Partitioned Coupling Method for the Simulation of Flow-Induced Fiber Motion

2019 ◽  
Author(s):  
Diwei Zhang ◽  
Xiaobo Peng ◽  
Dongdong Zhang
Keyword(s):  
Finite Element ◽  
Boundary Effect ◽  
Mixed Finite Element ◽  
Short Fiber ◽  
Coupling Method ◽  
Injection Molding Process ◽  
Molding Process ◽  
Axis Ratio ◽  
Fiber Motion ◽  
Coupling Strategy

Abstract A finite element based partitioned coupling method is presented for the simulation of flow-induced fiber motion in this paper. Quasi-static Stokes equation is used as the governing equation of the fluid domain. Mixed finite element is used to solve it. Fiber motion is modeled as a nonlinear geometric dynamic problem. Total-Lagrangian incremental finite element method is used to address the nonlinear geometry. Bathe method is applied to discretize the time domain. Then, two domains are coupled by a loosely partitioned coupling strategy. The derived method can be applied to the simulations of fiber motion in the low Reynolds number fluid, e.g. an injection molding process for manufacturing short fiber reinforced composite materials. In this paper, the effects of fiber shape, axis ratio of fiber, and boundary effect on the fiber’s motion are discussed. A phenomenon of repulsion is found in a simulation of the double-particle motion immersed in the double Couette flow.

scholarly journals Measures describing curvilinear short fiber distributions

2020 ◽  
Author(s):  
Stefan Hartmann ◽  
Teresa Liese
Keyword(s):  
Short Fiber ◽  
Mean Deviation ◽  
Injection Molding Process ◽  
Molding Process ◽  
Reinforced Plastics ◽  
Straight Line ◽  
Data Points ◽  
Fiber Reinforced Plastics ◽  
Ct Data ◽  
Continuous Interpolation

Abstract In this article, we discuss measures for fibers having a curvilinear shape. This is the case, for example, for man-made cellulose fibers having a weak stiffness. The fibers are bent during the injection molding process of short fiber reinforced plastics. For this purpose, $$\mu $$ μ -CT data can be evaluated and several measures can be introduced defining the geometrical orientation of the fibers. These measures are the length, a mean curvature, and the mean torsion. Furthermore, a mean orientation of a fiber and a mean deviation to a straight line can be defined. Additionally, to these measures, which are based on a continuous interpolation of given data points, discretized quantities only considering the data points are compared. Finally, the distributions of these measures at real $$\mu $$ μ -CT data are provided.

Micromechanical modeling and strength prediction of short fiber reinforced polymers

2012 ◽  
Vol 32 (1) ◽  
Author(s):  
Jan-Martin Kaiser ◽  
Markus Stommel
Keyword(s):  
Cost Benefit Analysis ◽  
Matrix Material ◽  
Mean Field ◽  
Cost Benefit ◽  
Short Fiber ◽  
Fiber Reinforced Polymers ◽  
Micromechanical Modeling ◽  
Strength Prediction ◽  
Injection Molding Process ◽  
Molding Process

Abstract In this contribution, the embedding and compatibility of commonly used strength criteria in practical engineering design (e.g., Tsai-Hill) into a two-step, mean-field, homogenization approach are investigated. This approach provides the opportunity to account for the heterogeneous microstructure of a polymer composite, caused by the non-unidirectional fiber distribution due to the injection molding process. In a first step, an incremental Mori-Tanaka homogenization scheme is applied to unidirectional sub-domains. In a second step, a Voigt model is used to compute the mechanical composite behavior of an entire domain, which itself is the composition of weighted sub-domains. The chosen two-step approach allows the application of models to predict the strength after both homogenization steps. This leads to two different strength prediction strategies. The selection of certain criteria in combination with the selected level of strength prediction influences the simulation results and the number of material tests necessary for calibration. These two aspects are directly linked to engineering expenses and they are evaluated in a cost benefit analysis. To account for elasto-plasticity, a second-moment formulation is used and extended. The extension allows the direct usage of experimental matrix material data, without having to introduce a virtual matrix as commonly necessary.

Efficient Multiscale Methods for Viscoelasticity and Fatigue of Short Fiber-Reinforced Polymers

2019 ◽  
Vol 809 ◽  
pp. 473-479
Author(s):  
Fabian Welschinger ◽  
Jonathan Köbler ◽  
Heiko Andrä ◽  
Ralf Müller ◽  
Matti Schneider ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Short Fiber ◽  
Industrial Applications ◽  
Multiscale Methods ◽  
Fiber Reinforced Polymers ◽  
Fast Fourier Transformation ◽  
Injection Molding Process ◽  
Fiber Reinforced ◽  
Molding Process ◽  
Numerical Effort

To predict the nonlinear mechanical behavior of components made of short fiber-reinforced plastics (SFRP) under long term and cyclic loading, coupled process and component simulations are required. The injection molding process leads to locally varying fiber orientations within the component. This varying microstructure [1] significantly influences the viscoelastic and fatigue behavior. The interaction between the microstructure [2] and the nonlinear macroscopic properties is resolved by a coupled fast Fourier transformation and finite element two-scale method (FFT-FEM), where the fiber orientation tensor is obtained by analyzing μCT images or by the corresponding process simulation. The aim of this work is to reduce the numerical costs of such a multiscale method. In a first step, the highly efficient micro-scale solver FeelMath [3,4] using an FFT-based preconditioner is presented. Afterwards, a numerical scheme based on a precomputed database trained with FeelMath simulations on the microscale and a model order reduction algorithm, is discussed. The combination of these ideas reduces the numerical effort, such that the method is applicable for industrial problems. Comparative studies of the fully coupled and reduced model document the high accuracy of this approach. The overall performance of this methodology is demonstrated by three-dimensional, industrial applications.

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