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Kim KH, Kim JH, Lim DH, Kwon BC, Hong J, Yoon HS, Cha SW. In Situ Changes in Mechanical Properties Based on Gas Saturation Inside Pressure Vessels. Polymers (Basel) 2024; 16:1276. [PMID: 38732744 PMCID: PMC11085073 DOI: 10.3390/polym16091276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 05/13/2024] Open
Abstract
In previous studies, difficulties were encountered in measuring changes within high-pressure vessels owing to limitations such as sensor connectors and sensor failures under high-pressure conditions. In addition, polymer-gas mixtures experience instantaneous gas desorption upon exiting high-pressure vessels owing to pressure differentials, leading to measurement errors. In this study, a device using magnetic sensors was developed to measure the real-time changes in gas-saturated polymers inside pressure vessels. Experiments on polymethyl methacrylate gas adsorption were conducted with parameters including pressure at 5 MPa and temperatures ranging from -20 to 40 °C for 60 and 180 min. It was observed that at -20 °C, the maximum magnetic field force density and deflection were 391.53 μT and 5.83 mm, respectively, whereas at 40 °C, deflection did not occur, with a value of 321.79 μT. Based on gas saturation experiments, a new model for deflection in high-pressure atmospheres is proposed. Additionally, an ANSYS analysis was conducted to predict the changes in Young's modulus based on gas saturation. In previous studies, mechanical properties were measured outside the pressure vessel, resulting in an error due to a pressure difference, while the proposed method is characterized by the ability to directly measure polymer behavior according to gas saturation in high-pressure vessels using a magnetic sensor in real time. Therefore, it is possible to predict polymer behavior, making it easy to control variables in high-pressure polymer processes.
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Affiliation(s)
- Kwan Hoon Kim
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Jae Hoo Kim
- Convergence Research Center for Solutions to Electromagnetic Interference in Future-Mobility, Korea Institute of Science and Technology (KIST), 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea;
| | - Dong Hwan Lim
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Byung Chul Kwon
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Jin Hong
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Ho Sub Yoon
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Sung Woon Cha
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
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2
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Huang PW, Peng HS. Fabrication, property characterization, and benefit analysis of mixing mechanism of nitrogen and melt, and its comparison of the porous-foam polypropylene injection molding parts. JOURNAL OF POLYMER ENGINEERING 2023. [DOI: 10.1515/polyeng-2022-0285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Abstract
In this study, an injection molding machine with a mixing mechanism of nitrogen (N2) and melt was designed, and the melt-fill/porous-foaming behavior is observed under the novel barrel design (plasticizing stage) of the gas/melt mixing for the porous injection molded thermoplastic. The thermoplastic employed in this study was polypropylene (PP), and the gas for forming the porous structure is N2. In addition, a thickness of 5 mm and a width of 10 mm paper-clip shape and the mold were constructed for studying the melt-fill-length and fill-length ratio through an experiment. The experimental results showed that the use of an injection molding machine with a mixing mechanism of N2 and melt decreased the melt-fill-length when the N2-output pressure was increased. The reason is that when the gas output, the speed of the screw will be affected. Therefore, during the gas/melt mixing and the plasticization rate will also affect the volume of the foam and the melt. But during plasticizing setting back pressure, can improve its melt volume reduction. When passing through the mixing mechanism and the injected melt, the melt is filled into the mold cavity, and the pressure in the melt is released/porous-foaming grows. At the same time, when the output pressure increases, the amount of melt in the injection barrel will decrease, and its relative porous structure/density distribution will increase. In addition, the mixing/flow direction of the melt impacted the density distribution and dispersion of porous foaming, thus the sample weight/shrinkage of melt-fill-length test sample (Mfl-ts) was improved.
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Affiliation(s)
- Po-Wie Huang
- Ph. D. Program of Mechanical and Aeronautical Engineering , College of Engineering, Feng Chia University , Taichung 40724 , Taiwan
| | - Hsin-Shu Peng
- Mechanical and Computer-Aided Engineering , College of Engineering, Feng Chia University , Taichung 40724 , Taiwan
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3
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Simon SA, Hain J, Sracic MW, Tewani HR, Prabhakar P, Osswald TA. Mechanical Response of Fiber-Filled Automotive Body Panels Manufactured with the Ku-Fizz TM Microcellular Injection Molding Process. Polymers (Basel) 2022; 14:polym14224916. [PMID: 36433043 PMCID: PMC9695732 DOI: 10.3390/polym14224916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
To maximize the driving range and minimize the associated energy needs and, thus, the number of batteries of electric vehicles, OEMs have adopted lightweight materials, such as long fiber-reinforced thermoplastics, and new processes, such as microcellular injection molding. These components must withstand specific loading conditions that occur during normal operation. Their mechanical response depends on the fiber and foam microstructures, which in turn are defined by the fabrication process. In this work, long fiber thermoplastic door panels were manufactured using the Ku-FizzTM microcellular injection molding process and were tested for their impact resistance, dynamic properties, and vibration response. Material constants were compared to the properties of unfoamed door panels. The changes in mechanical behavior were explained through the underlying differences in their respective microstructures. The specific storage modulus and specific elastic modulus of foamed components were within 10% of their unfoamed counterparts, while specific absorbed energy was 33% higher for the foamed panel by maintaining the panel's mass/weight.
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Affiliation(s)
- Sara Andrea Simon
- Polymer Engineering Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: ; Tel.: +1-608-358-1158
| | - Jörg Hain
- Volkswagen AG, Open Hybrid LabFactory, 38440 Wolfsburg, Germany
| | - Michael W. Sracic
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, WI 53711, USA
| | - Hridyesh R. Tewani
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Pavana Prabhakar
- Polymer Engineering Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Tim A. Osswald
- Polymer Engineering Center, University of Wisconsin-Madison, Madison, WI 53706, USA
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4
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Rajak DK, Wagh PH, Linul E. A Review on Synthetic Fibers for Polymer Matrix Composites: Performance, Failure Modes and Applications. MATERIALS 2022; 15:ma15144790. [PMID: 35888257 PMCID: PMC9321205 DOI: 10.3390/ma15144790] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/29/2022] [Accepted: 07/05/2022] [Indexed: 01/24/2023]
Abstract
In the last decade, synthetic fiber, as a reinforcing specialist, has been mainly used in polymer matrix composites (PMC’s) to provide lightweight materials with improved stiffness, modulus, and strength. The significant feature of PMC’s is their reinforcement. The main role of the reinforcement is to withstand the load applied to the composite. However, in order to fulfill its purpose, the reinforcements must meet some basic criteria such as: being compatible with the matrix, making chemical or adhesion bonds with the matrix, having properties superior to the matrix, presenting the optimal orientation in composite and, also, having a suitable shape. The current review reveals a detailed study of the current progress of synthetic fibers in a variety of reinforced composites. The main properties, failure modes, and applications of composites based on synthetic fibers are detailed both according to the mentioned criteria and according to their types (organic or inorganic fibers). In addition, the choice of classifications, applications, and properties of synthetic fibers is largely based on their physical and mechanical characteristics, as well as on the synthesis process. Finally, some future research directions and challenges are highlighted.
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Affiliation(s)
- Dipen Kumar Rajak
- Department of Mechanical Engineering, G. H. Raisoni Institute of Business Management, Jalgaon 425002, MH, India
- Correspondence: (D.K.R.); (E.L.)
| | - Pratiksha H. Wagh
- Department of Mechanical Engineering, G. H. Raisoni Institute of Engineering and Technology, Pune 412207, MH, India;
| | - Emanoil Linul
- Department of Mechanics and Strength of Materials, Politehnica University Timisoara, 300 222 Timisoara, Romania
- Correspondence: (D.K.R.); (E.L.)
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5
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Conventional and Microcellular Injection Molding of a Highly Filled Polycarbonate Composite with Glass Fibers and Carbon Black. Polymers (Basel) 2022; 14:polym14061193. [PMID: 35335523 PMCID: PMC8950788 DOI: 10.3390/polym14061193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/25/2022] Open
Abstract
Conventional solid injection molding (CIM) and microcellular injection molding (MIM) of a highly filled polycarbonate (PC) composite with glass fibers and carbon black were performed for molding ASTM tensile test bars and a box-shape part with variable wall thickness. A scanning electron microscope (SEM) was used to examine the microstructure at the fractured surface of the tensile test bar samples. The fine and uniform cellular structure suggests that the PC composite is a suitable material for foaming applications. Standard tensile tests showed that, while the ultimate strength and elongation at break were lower for the foamed test bars at 4.0–11.4% weight reduction, their specific Young’s modulus was comparable to that of their solid counterparts. A melt flow and transition model was proposed to explain the unique, irregular “tiger-stripes” exhibited on the surface of solid test bars. Increasing the supercritical fluid (SCF) dosage and weight reduction of foamed samples resulted in swirl marks on the part surface, making the tiger-stripes less noticeable. Finally, it was found that an injection pressure reduction of 25.8% could be achieved with MIM for molding a complex box-shaped part in a consistent and reliable fashion.
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Metal Additive Manufacturing of Plastic Injection Molds with Conformal Cooling Channels. Polymers (Basel) 2022; 14:polym14030424. [PMID: 35160414 PMCID: PMC8838397 DOI: 10.3390/polym14030424] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 02/06/2023] Open
Abstract
Conformal cooling channels (CCCs) are widely used in the plastic injection molding process to improve the product quality and operational performance. Tooling that incorporates CCCs can be fabricated through metal additive manufacturing (MAM). The present work focuses on the MAM of a plastic injection mold insert with different CCC types that are circular, serpentine, and tapered channels with/without body-centered cubic (BCC) lattices. The entire manufacturing process of the mold insert is explained from the design step to the final printing step including the computational thermal & mechanical simulations, performance assessments, and multiobjective optimization. Compared to the traditional channels, conformal cooling channels achieved up to 62.9% better cooling performance with a better thermal uniformity on the mold surface. The optimum mold geometry is decided using the multiobjective optimization procedure according to the multiple objectives of cooling time, temperature non-uniformity, and pressure drop in the channel. Direct Metal Laser Sintering (DMLS) method is used for manufacturing the molds and the quality of the printed molds are analyzed with the X-ray Computed Tomography (X-ray CT) technique. The errors between the design and the printed parameters are less than 5% for the circular and tapered channels while the maximum deviation of the strut diameters of the BCC is 0.06 mm.
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Kim HK, Kim J, Kim D, Ryu Y, Cha SW. Vibration and Sound Response of Glass-Fiber-Reinforced Polyamide 6 Using Microcellular-Foaming-Process-Applied Injection Molding Process. Polymers (Basel) 2022; 14:polym14010173. [PMID: 35012195 PMCID: PMC8747395 DOI: 10.3390/polym14010173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/18/2021] [Accepted: 12/30/2021] [Indexed: 02/04/2023] Open
Abstract
In this study, the vibration and sound response characteristics of composites produced via injection molding applied with a microcellular foaming process (MCPs) were improved. The study was conducted using PA6 and glass fiber composites, which are representative thermoplastic engineering plastics. Two types of specimens were used: a plate specimen to confirm the basic sound and vibration characteristics, and a large roof-rack specimen from an actual vehicle with a complex shape. The frequency response function curve was calculated by conducting an impact test, and natural frequency and damping ratio were measured based on the curve. The results confirmed that, in the case of a specimen manufactured through the injection molding process to which MCPs were applied, the natural frequency was lowered, and the damping ratio decreased. The degree of change in the natural frequency and damping ratio was confirmed. To determine the cause of the change in the natural frequency and damping ratio, the mode shape at the natural frequency of each specimen was measured and the relationship was confirmed by measuring the density and the elastic modulus of the composite. In addition, the usability of the specimens to which MCPs were applied was verified by conducting impact strength and tensile strength tests.
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8
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Rajak DK, Wagh PH, Linul E. Manufacturing Technologies of Carbon/Glass Fiber-Reinforced Polymer Composites and Their Properties: A Review. Polymers (Basel) 2021; 13:polym13213721. [PMID: 34771276 PMCID: PMC8588351 DOI: 10.3390/polym13213721] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Over the last few years, there has been a growing interest in the study of lightweight composite materials. Due to their tailorable properties and unique characteristics (high strength, flexibility and stiffness), glass (GFs) and carbon (CFs) fibers are widely used in the production of advanced polymer matrix composites. Glass Fiber-Reinforced Polymer (GFRP) and Carbon Fiber-Reinforced Polymer (CFRP) composites have been developed by different fabrication methods and are extensively used for diverse engineering applications. A considerable amount of research papers have been published on GFRP and CFRP composites, but most of them focused on particular aspects. Therefore, in this review paper, a detailed classification of the existing types of GFs and CFs, highlighting their basic properties, is presented. Further, the oldest to the newest manufacturing techniques of GFRP and CFRP composites have been collected and described in detail. Furthermore, advantages, limitations and future trends of manufacturing methodologies are emphasized. The main properties (mechanical, vibrational, environmental, tribological and thermal) of GFRP and CFRP composites were summarized and documented with results from the literature. Finally, applications and future research directions of FRP composites are addressed. The database presented herein enables a comprehensive understanding of the GFRP and CFRP composites’ behavior and it can serve as a basis for developing models for predicting their behavior.
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Affiliation(s)
- Dipen Kumar Rajak
- Department of Mechanical Engineering, G. H. Raisoni Institute of Business Management, Jalgaon 425002, MH, India
- Correspondence: (D.K.R.); (E.L.)
| | - Pratiksha H. Wagh
- Department of Mechanical Engineering, G. H. Raisoni Institute of Engineering and Technology, Pune 412207, MH, India;
| | - Emanoil Linul
- Department of Mechanics and Strength of Materials, Politehnica University Timisoara, 300 222 Timisoara, Romania
- Correspondence: (D.K.R.); (E.L.)
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Ding Y, Hassan MH, Bakker O, Hinduja S, Bártolo P. A Review on Microcellular Injection Moulding. MATERIALS 2021; 14:ma14154209. [PMID: 34361403 PMCID: PMC8348032 DOI: 10.3390/ma14154209] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/02/2022]
Abstract
Microcellular injection moulding (MuCell®) is a polymer processing technology that uses a supercritical fluid inert gas, CO2 or N2, to produce light-weight products. Due to environmental pressures and the requirement of light-weight parts with good mechanical properties, this technology recently gained significant attention. However, poor surface appearance and limited mechanical properties still prevent the wide applications of this technique. This paper reviews the microcellular injection moulding process, main characteristics of the process, bubble nucleation and growth, and major recent developments in the field. Strategies to improve both the surface quality and mechanical properties are discussed in detail as well as the relationships between processing parameters, morphology, and surface and mechanical properties. Modelling approaches to simulate microcellular injection moulding and the mathematical models behind Moldex 3D and Moldflow, the two most commonly used software tools by industry and academia, are reviewed, and the main limitations are highlighted. Finally, future research perspectives to further develop this technology are also discussed.
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Affiliation(s)
- Yifei Ding
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Mohammed H Hassan
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Otto Bakker
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Srichand Hinduja
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Paulo Bártolo
- Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
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Mohd Hanid MH, Abd Rahim SZ, Gondro J, Sharif S, Al Bakri Abdullah MM, Zain AM, El-hadj Abdellah A, Mat Saad MN, Wysłocki JJ, Nabiałek M. Warpage Optimisation on the Moulded Part with Straight Drilled and Conformal Cooling Channels Using Response Surface Methodology (RSM), Glowworm Swarm Optimisation (GSO) and Genetic Algorithm (GA) Optimisation Approaches. MATERIALS 2021; 14:ma14061326. [PMID: 33802032 PMCID: PMC8000972 DOI: 10.3390/ma14061326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/22/2021] [Accepted: 03/02/2021] [Indexed: 10/29/2022]
Abstract
It is quite challenging to control both quality and productivity of products produced using injection molding process. Although many previous researchers have used different types of optimisation approaches to obtain the best configuration of parameters setting to control the quality of the molded part, optimisation approaches in maximising the performance of cooling channels to enhance the process productivity by decreasing the mould cycle time remain lacking. In this study, optimisation approaches namely Response Surface Methodology (RSM), Genetic Algorithm (GA) and Glowworm Swarm Optimisation (GSO) were employed on front panel housing moulded using Acrylonitrile Butadiene Styrene (ABS). Each optimisation method was analysed for both straight drilled and Milled Groove Square Shape (MGSS) conformal cooling channel moulds. Results from experimental works showed that, the performance of MGSS conformal cooling channels could be enhanced by employing the optimisation approach. Therefore, this research provides useful scientific knowledge and an alternative solution for the plastic injection moulding industry to improve the quality of moulded parts in terms of deformation using the proposed optimisation approaches in the used of conformal cooling channels mould.
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Affiliation(s)
- Mohd Hazwan Mohd Hanid
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Arau 02600, Perlis, Malaysia;
- Center of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia;
- Correspondence: (M.H.M.H.); (S.Z.A.R.)
| | - Shayfull Zamree Abd Rahim
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Arau 02600, Perlis, Malaysia;
- Center of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia;
- Correspondence: (M.H.M.H.); (S.Z.A.R.)
| | - Joanna Gondro
- Department of Physics, Częstochowa University of Technology, 42-200 Częstochowa, Poland; (J.G.); (J.J.W.); (M.N.)
| | - Safian Sharif
- Faculty of Engineering, Universiti Teknologi Malaysia, UTM Skudai 81310, Johor, Malaysia; (S.S.); (A.M.Z.)
| | - Mohd Mustafa Al Bakri Abdullah
- Center of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia;
- Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Azlan Mohd Zain
- Faculty of Engineering, Universiti Teknologi Malaysia, UTM Skudai 81310, Johor, Malaysia; (S.S.); (A.M.Z.)
| | - Abdellah El-hadj Abdellah
- Laboratory of Mechanics, Physics and Mathematical Modelling (LMP2M), University of Medea, Medea 26000, Algeria;
| | - Mohd Nasir Mat Saad
- Faculty of Mechanical Engineering Technology, Universiti Malaysia Perlis, Arau 02600, Perlis, Malaysia;
- Center of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia;
| | - Jerzy J. Wysłocki
- Department of Physics, Częstochowa University of Technology, 42-200 Częstochowa, Poland; (J.G.); (J.J.W.); (M.N.)
| | - Marcin Nabiałek
- Department of Physics, Częstochowa University of Technology, 42-200 Częstochowa, Poland; (J.G.); (J.J.W.); (M.N.)
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Microstructure and Properties of Glass Fiber-Reinforced Polyamide/Nylon Microcellular Foamed Composites. Polymers (Basel) 2020; 12:polym12102368. [PMID: 33076464 PMCID: PMC7602564 DOI: 10.3390/polym12102368] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 11/17/2022] Open
Abstract
The automobile and aerospace industries require lightweight and high-strength structural parts. Nylon-based microcellular foamed composites have the characteristics of high strength and the advantages of being lightweight as well as having a low production cost and high product dimensional accuracy. In this work, the glass fiber-reinforced nylon foams were prepared through microcellular injection molding with supercritical fluid as the blowing agent. The tensile strength and weight loss ratio of microcellular foaming composites with various injection rates, temperatures, and volumes were investigated through orthogonal experiments. Moreover, the correlations between dielectric constant and injection volume were also studied. The results showed that the "slow-fast" injection rate, increased temperature, and injection volume were beneficial to improving the tensile strength and strength/weight ratios. Meanwhile, the dielectric constant can be decreased by building the microcellular structure in nylon, which is associated with the weight loss ratio extent closely.
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12
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Ryu Y, Sohn JS, Yun CS, Cha SW. Shrinkage and Warpage Minimization of Glass-Fiber-Reinforced Polyamide 6 Parts by Microcellular Foam Injection Molding. Polymers (Basel) 2020; 12:polym12040889. [PMID: 32290507 PMCID: PMC7240735 DOI: 10.3390/polym12040889] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 04/09/2020] [Indexed: 12/02/2022] Open
Abstract
Shrinkage and warpage of injection-molded parts can be minimized by applying microcellular foaming technology to the injection molding process. However, unlike the conventional injection molding process, the optimal conditions of the microcellular foam injection molding process are elusive because of core differences such as gas injection. Therefore, this study aims to derive process conditions to minimize the shrinkage and warpage of microcellular foam injection-molded parts made of glass fiber reinforced polyamide 6 (PA6/GF). Process factors and levels were first determined, with experiments planned accordingly. We simulated designed experiments using injection molding analysis software, and the results were analyzed using the Taguchi method, analysis of variance (ANOVA), and response surface methodology (RSM), with the ANOVA analysis being ultimately demonstrating the influence of the factors. We derived and verified the optimal combination of process factors and levels for minimizing both shrinkage and warpage using the Taguchi method and RSM. In addition, the mechanical properties and cell morphology of PA6/GF, which change with microcellular foam injection molding, were confirmed.
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13
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Wang J, Chai J, Wang G, Zhao J, Zhang D, Li B, Zhao H, Zhao G. Strong and thermally insulating polylactic acid/glass fiber composite foam fabricated by supercritical carbon dioxide foaming. Int J Biol Macromol 2019; 138:144-155. [DOI: 10.1016/j.ijbiomac.2019.07.071] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/09/2019] [Accepted: 07/09/2019] [Indexed: 11/30/2022]
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14
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Ryu Y, Sohn JS, Kweon BC, Cha SW. Shrinkage Optimization in Talc- and Glass-Fiber-Reinforced Polypropylene Composites. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E764. [PMID: 30845669 PMCID: PMC6427219 DOI: 10.3390/ma12050764] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 11/16/2022]
Abstract
The shrinkage of reinforced polymer composites in injection molding varies, depending on the properties of the reinforcing agent. Therefore, the study of optimal reinforcement conditions, to minimize shrinkage when talc and glass fibers (GF) (which are commonly used as reinforcements) are incorporated into polypropylene (PP), is required. In this study, we investigated the effect of reinforcement factors, such as reinforcement type, reinforcement content, and reinforcement particle size, on the shrinkage, and optimized these factors to minimize the shrinkage of the PP composites. We measured the shrinkage of injection-molded samples, and, based on the measured values, the optimal conditions were obtained through analysis of variance (ANOVA), the Taguchi method, and regression analysis. It was found that reinforcement type had the largest influence on shrinkage among the three factors, followed by reinforcement content. In contrast, the reinforcement size was not significant, compared to the other two factors. If the reinforcement size was set as an uncontrollable factor, the optimum condition for minimizing directional shrinkage was the incorporation of 20 wt % GF and that for differential shrinkage was the incorporation of 20 wt % talc. In addition, a shrinkage prediction method was proposed, in which two reinforcing agents were incorporated into PP, for the optimization of various dependent variables. The results of this study are expected to provide answers about which reinforcement agent should be selected and incorporated to minimize the shrinkage of PP composites.
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Affiliation(s)
- Youngjae Ryu
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Korea.
| | - Joo Seong Sohn
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Korea.
| | - Byung Chul Kweon
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Korea.
| | - Sung Woon Cha
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Korea.
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