VARTM Process Improvement for Repeatable and Improved Mechanical Properties of Composite Laminates

2009 ◽  
Author(s):  
Sanjay Sharma ◽  
Dennis A. Siginer
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Void Content ◽  
Molding Process ◽  
Fiber Volume ◽  
The Impact ◽  
Vartm Process

Quality of laminates produced by Seeman Composite Resin Infusion Molding Process (SCRIMP) is studied by comparing their Fiber Volume fraction and void content. SCRIMP is a variant of Vacuum Assisted Resin Transfer Molding (VARTM). Manufacturing process parameters are then identified and varied to study the impact on mechanical properties of laminated composites. Modification to SCRIMP is carried out by infusing the resin under additional pressure. Optimal process parameters for this modified SCRIMP process are suggested to yield laminates that are repeatable and consistent in quality. Void content is reduced in the composite laminates by altering the vacuum pressure level. Thickness gradient commonly found in SCRIMP processed laminates is eliminated by allowing longer de-bulking time. Final laminate quality is measured using ASTM standardized mechanical testing.

Pressurized Infusion: A New and Improved Liquid Composite Molding Process

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
M. Akif Yalcinkaya ◽  
Gorkem E. Guloglu ◽  
Maya Pishvar ◽  
Mehrad Amirkhosravi ◽  
E. Murat Sozer ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Compaction Pressure ◽  
External Pressure ◽  
Void Content ◽  
Liquid Composite Molding ◽  
Molding Process ◽  
Fiber Volume

Vacuum-assisted resin transfer molding (VARTM) has several inherent shortcomings such as long mold filling times, low fiber volume fraction, and high void content in fabricated laminates. These problems in VARTM mainly arise from the limited compaction of the laminate and low resin pressure. Pressurized infusion (PI) molding introduced in this paper overcomes these disadvantages by (i) applying high compaction pressure on the laminate by an external pressure chamber placed on the mold and (ii) increasing the resin pressure by pressurizing the inlet resin reservoir. The effectiveness of PI molding was verified by fabricating composite laminates at various levels of chamber and inlet pressures and investigating the effect of these parameters on the fill time, fiber volume fraction, and void content. Furthermore, spatial distribution of voids was characterized by employing a unique method, which uses a flatbed scanner to capture the high-resolution planar scan of the fabricated laminates. The results revealed that PI molding reduced fill time by 45%, increased fiber volume fraction by 16%, reduced void content by 98%, improved short beam shear (SBS) strength by 14%, and yielded uniform spatial distribution of voids compared to those obtained by conventional VARTM.

Manufacturing Modeling of Three-Dimensional Resin Injection Pultrusion Process Control Parameters for Polyester/Glass Rovings Composites

2006 ◽  
Vol 129 (1) ◽  
pp. 143-156 ◽  
Author(s):  
A. L. Jeswani ◽  
J. A. Roux
Keyword(s):  
Process Parameters ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Fiber Reinforcement ◽  
Resin Flow ◽  
Molding Process ◽  
Fiber Volume ◽  
Liquid Resin ◽  
Pultrusion Process ◽  
The Impact

Pultrusion, sometimes referred to as continuous resin transfer molding process, is a continuous, cost-effective method for manufacturing composite materials with constant cross sections (such as rod stock, beams, channels, and tubing). The objective of this study is to improve the fiber reinforcement wetout and thus the quality of the pultruded part in the injection pultrusion process. The complete wetout of the dry reinforcement by the liquid resin depends on various design and process parameters. The process parameters modeled in this study are fiber pull speed, fiber volume fraction, and viscosity of the resin. In the present work, a three-dimensional finite volume technique is employed to simulate the liquid resin flow through the fiber reinforcement in the injection pultrusion process. The numerical model simulates the flow of polyester resin through the glass rovings and predicts the impact of the process parameters on wetout, resin pressure field, and resin velocity field. The location of the liquid resin flow front has been predicted for an injection slot as well as for five discrete injection ports.

Applying Magnetic Consolidation Pressure During Cure to Improve Laminate Quality: A Comparative Analysis of Wet Lay-Up and Vacuum Assisted Resin Transfer Molding Processes

2017 ◽  
Author(s):  
Maya Pishvar ◽  
Mehrad Amirkhosravi ◽  
M. Cengiz Altan
Keyword(s):  
Composite Laminates ◽  
Permanent Magnets ◽  
Volume Fraction ◽  
Resin Transfer Molding ◽  
Void Content ◽  
Fiber Volume ◽  
Transfer Molding ◽  
Consolidation Pressure ◽  
A New Technique

This paper presents the application of a new technique, Magnet Assisted Composite Manufacturing (MACM), to enhance the quality of composite laminates fabricated by wet lay-up/vacuum bag (WLVB) and vacuum assisted resin transfer molding (VARTM). Towards this goal, a set of high-power, Neodymium permanent magnets, which are placed on a magnetic tool plate, is applied on the vacuum bag/lay-up. To further demonstrate the effectiveness of MACM, six-ply random mat, E-glass/epoxy composite laminates are produced under four processing scenarios: (i) Conventional WLVB; (ii) WLVB with magnetic consolidation; (iii) Conventional VARTM; and (iv) VARTM with magnetic consolidation. Applying magnetic consolidation pressure is found to be a convenient and efficient method for enhancing the overall quality of the laminates fabricated by WLVB and VARTM. For instance, in WLVB-MACM process, fiber volume fraction improves by 98% to 49% and void content reduces from 5% to less than 1.5% compared to conventional WLVB. These two factors lead to substantially increased mechanical properties of the WLVB-MACM laminates to a level comparable to those achieved by the higher-cost VARTM-MACM process.

scholarly journals Peningkatan Sifat Mekanik Komposit Serat Alam Limbah Sabut Kelapa (Cocofiber) yang Biodegradable

2021 ◽  
Vol 6 (1) ◽  
pp. 30-37
Author(s):  
Sri Hastuti ◽  
Herru Santosa Budiono ◽  
Diki Ilham Ivadiyanto ◽  
Muhammad Nurdin Nahar
Keyword(s):  
Mechanical Properties ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Composites ◽  
Coconut Fiber ◽  
Fiber Volume ◽  
Coconut Coir ◽  
The Impact

Inovasi baru serat dari sabut kelapa dimanfaatkan untuk meningkatkan nilai ekonomis dari serat sabut kelapa, oleh karena itu dirancanglah pendayagunaan serat dari sabut kelapa untuk penguat komposit dengan material serat alam yang biodegradable. Hal ini untuk mendukung penggunaan komposit yang ramah terhadap lingkungan dan mengurangi penggunaan material komposit serat sintetis yang polutan. Tujuan penelitian adalah menganalisis sifat mekanik pada komposit serat alam bermaterial serat dari sabut kelapa yang ramah lingkungan. Metode penelitian pembuatan komposit berpenguat serat dari sabut kelapa dilakukan treatment NaOH 15% selama 5 jam dan fraksi volume serat 10 %, 15 %, dan 20 %. Komposit  serat dari sabut kelapa dengan matriks UPRs 157 BQTN dengan hardener MEXPO. Pengujian mekanik dilakukan uji bending menggunakan standar ASTM D790 dan uji impak  menggunakan standar ASTM D5941.  Pengujian impak komposit serat alam menunjukkan ketangguhan impak komposit pada fraksi volume serat 20% dengan nilai 0.017588J/mm2. Hasil pengujian menunjukkan peningkatan fraksi volume serta berpengaruh terhadap peningkatan kekuatan bending komposit serat dari sabut kelapa  dengan kekuatan optimum bending pada fraksi volume serat 10% dengan nilai 44,33N/mm2. Hal ini menunjukkan peningkatan fraksi volume serat dengan perendaman NaOH 15% akan meningkatkan sifat mekanik bending dan impak komposit. Perendaman NaOH memberikan pengaruh daya serap sabut kelapa terhadap matrik Unsaturated Polyester yang dapat meningkatkan daya rekat antara penguat serat dengan matrik sehingga meningkatkan sifat mekanik bending dan impak komposit. ABSTRACT The innovation of coco fiber is used to increase the economic value of coconut coir, therefore the utilization of coconut fiber for reinforcing composites with biodegradable natural fiber material is designed. This is to support the use of composites that are friendly to the environment and reduce the use of pollutant synthetic fiber composite materials. The research objective was to analyze the mechanical properties of natural fiber composites with environmentally friendly coconut fiber as material. The research method of making fiber-reinforced composites from coconut coir was carried out by 15% NaOH treatment for 5 hours and a fiber volume fraction of 10%, 15%, and 20%. Composite fiber from coconut coir with UPRs 157 BQTN matrix with MEXPO hardener. Mechanical testing is carried out using the ASTM D790 standard and the impact test using the ASTM D5941 standard. The impact test of natural fiber composites showed the impact toughness of the composite at a fiber volume fraction of 20% with a value of 0.017588 J/ mm2. The test results showed an increase in volume fraction and an effect on the increase in the bending strength of coconut fiber composites with the optimum bending strength at a fiber volume fraction of 10% with a value of 44.33N /mm2. This shows that the increase in fiber volume fraction by immersion in 15% NaOH will increase the bending mechanical properties and the impact of the composite. Soaking NaOH has an effect on the absorption power of coconut coir on the Unsaturated Polyester matrix which can increase the adhesion between the fiber reinforcement and the matrix thereby increasing the bending mechanical properties and impact of the composite.

Effects of vacuum pressure, inlet pressure, and mold temperature on the void content, volume fraction of polyester/e-glass fiber composites manufactured with VARTM process

2011 ◽  
Vol 45 (26) ◽  
pp. 2727-2742 ◽  
Author(s):  
Vishwanath R. Kedari ◽  
Basil I. Farah ◽  
Kuang-Ting Hsiao
Keyword(s):  
Glass Fiber ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Mold Temperature ◽  
Vacuum Pressure ◽  
Inlet Pressure ◽  
Void Content ◽  
Fiber Volume ◽  
Vartm Process

Vacuum-assisted resin transfer molding (VARTM) process is one of the liquid composite molding (LCM) processes aimed at producing high-quality composite parts. The void content and fiber volume fraction of a VARTM part can be affected by many parameters and is critical to the mechanical properties and the quality of the part. In this paper, a series of experiments were conducted with a heated dual pressure control VARTM setup for investigating the effects of vacuum pressure, inlet pressure, and mold temperature on the void content and fiber volume fraction of polyester/E-glass fiber composite. It was found that stronger vacuum and higher mold temperature can better control and increase the fiber volume fraction; however, such a combination of strong vacuum and high mold temperature may also require a reduced inlet pressure for minimizing the void content. The need of pressure reduction can be explained with the compatibility between Darcy's flow and capillary flow in the fiber preform and can be calculated based on the room temperature VARTM results. The experimental results suggest that high mold temperature, high vacuum, and appropriately reduced inlet pressure can produce a VARTM part with high fiber volume fraction and low void content.

Processing Effects on Formation of Microvoids and Hydraulic Fluid Absorption of Quartz/BMI Laminates

2015 ◽  
Author(s):  
Keith R. Hurdelbrink ◽  
Jacob P. Anderson ◽  
Zahed Siddique ◽  
M. Cengiz Altan
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Void Content ◽  
Hydraulic Fluid ◽  
Processing Conditions ◽  
Fluid Absorption ◽  
Fiber Volume ◽  
Fluid Content

Bismaleimide (BMI) resin with Quartz (AQ581) fiber reinforcement is desirable for systems requiring a high glass transition temperature, low dielectric properties, and high laminate mechanical properties. These properties make quartz/BMI an ideal composite material for complex aerospace structures, and are currently being used in various aircraft engine cowlings and radomes. In addition to moisture absorption, quartz/BMI composite laminates are often exposed to different types of hydraulic fluid contaminants, which may lead to anomalous absorption behavior over the service life of the composite structure. Variations in laminate processing conditions, such as prepreg preconditioning and fabrication cure pressure, can have a significant effect on microstructural features of fiber-reinforced composites. Microstructural features, such as fiber volume fraction and void content, can influence mechanical properties and long term absorption of moisture or other liquid contaminants. In this paper, the process-induced microstructure and hydraulic fluid absorption behavior of quartz/BMI laminates are presented. The laminates are fabricated from preconditioned prepregs and cured at different pressures to generate different levels of microvoids, while keeping the fiber volume fraction constant. Location, size and morphology of microvoids are investigated via SEM images obtained from laminates cured at different processing conditions. Composite samples were prepared and fully-immersed in hydraulic fluid at room temperature, and were not subjected to any prior degradation. The laminate samples immersed in hydraulic fluid exhibited clear non-Fickian absorption behavior, which was successfully predicted by the one-dimensional Hindered Diffusion Model (HDM). The degree of non-Fickian absorption behavior, or hindrance coefficient (μ), ranged from 0.30 to 0.72. Model prediction indicates that as the fabrication pressure increased, the maximum fluid content (M∞) decreased considerably. Additionally, a reduction in maximum fluid content was observed when lower relative humidity environments were used for prepreg preconditioning. A discernable difference was not observed in the absorption dynamics when the prepregs were preconditioned at greater than 70% relative humidity.

scholarly journals Effect of permeability on GFRP laminate produced by VARTM process

2020 ◽  
Vol 184 ◽  
pp. 01029
Author(s):  
Bairoju Shankarachary ◽  
N Sateesh ◽  
Lavu Gopinath ◽  
Siripuram Aparna
Keyword(s):  
Glass Fiber ◽  
Process Parameters ◽  
Considerable Effect ◽  
Sem Analysis ◽  
Void Content ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Commercial Applications ◽  
The Impact

Vacuum assisted resin transfer molding (VARTM) is one of the manufacturing technique that is viable for production of fiber reinforced polymer composite components suitable for aerospace, marine and commercial applications. However the repeatable quality of the product can be achieved by critically fixing the process parameters such as Vacuum Pressure (VP) and permeability of the preform. The present investigation is aimed at studying the effect of permeability for production of Glass Fiber Reinforced Polyester (GFRP) components with consistent quality. The VARTM mould is made with an acrylic transparent top cover to observe and record the resin flow pattern. Six layers of randomly placed glass fiber under five different vacuum pressures VP1 = 0.013, VP2 = 0.026, VP3 = 0.039, VP4 = 0.053 and VP5 = 0.066 MPa were studied. The laminates produced by this process under the above mentioned conditions were characterized with ASTM D procedures so as to study the effect of these process parameters on the quality of the laminate. And as mentioned there is a considerable effect of permeability on the impact strength and the void content in the laminates under different vacuum pressures. SEM analysis of the impact tested fractured GFRP composites showed the bonding of fiber and matrix.

scholarly journals PENGARUH FRAKSI VOLUME SERAT TERHADAP SIFAT MEKANIS KOMPOSIT MATRIKS POLIMER POLYESTER DIPERKUAT SERAT AGAVE SISAL

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Gede Aprianto ◽  
I Nyoman Pasek Nugraha ◽  
Kadek Rihendra Dantes
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Repeated Measures ◽  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Repeated Measures Design ◽  
Pull Out ◽  
The Impact

Penelitian ini bertujuan untuk mengetahui fraksi volume terbaik dari sifat mekanik komposit matriks polimer polyester yang diperkuat serat alam agave sisal. Sifat mekanik yang dimaksud adalah kekuatan impak dan mikrografi. Desain penelitian yang digunakan dalam penelitian ini adalah penelitian eksperimen dengan metode single factor repeated measures design. Pembuatan sampel komposit matriks polimer polyester yang diperkuat serat alam agave sisal menggunakan metode hand lay up. Variasi fraksi volume serat yang digunakan adalah 0%, 20%, 40%, dan 60%. Setiap fraksi volume serat yang diuji, dibuatkan masing-masing 10 (sepuluh) buah spesimen. Data-data yang diperoleh dalam penelitian ini di dapat dari energi serap (Es) pengujian impak yang selanjutnya diolah dan dianalisa menggunakan Anava As. Hasil penelitian menunjukkan bahwa : (1) Fraksi volume serat terbaik dalam pengujian impak adalah fraksi volume serat 40% dengan kekuatan impak sebesar 4.092,00818 J/m2, sedangkan fraksi volume serat terendah adalah fraksi volume serat 0% dengan kekuatan impak sebesar 604,50120 J/m2; (2) Berdasarkan hasil pengujian mikrografi dari patahan hasil pengujian impak menunjukkan bahwa secara umum pola patahan yang terjadi pada komposit adalah kombinasi dari patahan getas (brittle fracture) dan pull-out fibers fracture atau dikenal dengan patahan sikat (brush fracture). Kesimpulan dari penelitian ini adalah fraksi volume serat 40% memiliki sifat mekanik terbaik dibandingkan dengan fraksi volume serat lainnya sehingga dapat dijadikan sebagai salah satu bahan baku alternatif pengganti serat gelas, dimana kekuatan impak yang dihasilkan sebesar 4.092,00818 J/m2. Dilihat dari hasil pengujian mikrografi, secara umum dikategorikan memiliki pola patahan sikat (brush fracture).Kata Kunci : komposit, matriks polimer polyester, serat alam agave sisal, sifat mekanis This research aims to know the best fiber volume fraction on mechanical properties of agave sisal natural fiber which is reinforced by polyester matrix composites. Those mechanical properties are the impact strength and the micrographic. The research design used in this research is an experimental research with single factor repeated measures design method. The manufacture of agave sisal natural fiber which is reinforced by polyester matrix composites specimens used hand lay-up methods. The variations of the fiber volume fraction used were 0%, 20%, 40% and 60%. There are 10 (ten) pieces of specimens for each tested fiber volume fraction. The research data was obtained from specimens absorbed energy (Es). Then, they were processed and analyzed by using Anova As. The result of this research showed that: (1) the best fiber volume fraction during impact testing is 40% with 4.092,00818 J/m2 of the impact strength. Meanwhile, the worst fiber volume fraction is 0% with 604,50120 J/m2 of the impact strength; (2) based on the micrographic test, the fractures from the impact test showed that the pattern of those fractures generally consists the combination of brittle fractures and pull-out fiber fractures. This combination is known as brush fractures. The conclusion of this research is the 40% of fiber volume fraction has the best mechanical properties compared to the other fiber volume fraction. Thus, it can be used as the alternative raw material for fiberglass. The impact strength produced was 4.092,00818 J/m2. Based from the micrographic test, the fraction is categorized as the brush fractures pattern.keyword : agave sisal natural fiber, composite, material properties, polyester polymer matrix

scholarly journals Degassing and layers variation effect on composite processing by vacuum assisted resin transfer moulding

2021 ◽  
Vol 9 ◽  
Author(s):  
Alpa Tapan Bhatt ◽  
◽  
Piyush P Gohil ◽  
Vijaykumar Chaudhary ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Critical Issue ◽  
Thickness Variation ◽  
Void Content ◽  
Vacuum Degassing ◽  
Reinforced Composite ◽  
Before And After ◽  
Transfer Moulding ◽  
Vartm Process

Vacuum assisted resin transfer molding (VARTM) is a fiber reinforced composite (FRC) making process in which resin is impregnated to fabric by application of vacuum. This process is also known as vacuum infusion process. The critical issue in VARTM process is void generation. Voids form due to variety of reasons, most of which can be avoided. Vacuum degassing is one of the solutions which will reduce air entrapped inside resin during impregnation. In this work six laminates from jute and polyester resin were prepared, three with degassing and three without degassing with variation in number of jute layers 5, 10 and 15 respectively. Microscopic examination and mechanical properties have been observed before and after degassing. It was observed that degassing improves mechanical properties of composite laminates and reduce void content. It was observed that the thickness variation in laminate increased as number of layer increased.

The Hand Making of Radius Fillers and the Establishment of its Evaluative Requirements

2014 ◽  
Vol 936 ◽  
pp. 1973-1984
Author(s):  
Hai Lei Wang ◽  
Mei Rong Xiong ◽  
Yue Xin Duan ◽  
Jin Yang ◽  
Dong Xiu Yan ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Nondestructive Testing ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Void Content ◽  
Filling Material ◽  
Fiber Volume ◽  
Composite Girder ◽  
Microstructure And Mechanical Property

Radius filler is a kind of filling material which is used in triangle gap of the composite girder and rib. To optimize the hand-made craft of radius fillers and specify the evaluative requirements for detecting radius fillers, a research on handcraft parameters of the radius fillers had been conducted; the boundary dimension, microstructure and mechanical property of the R6 radius fillers had been characterized with the use of different detective methods and the microanalysis includes: nondestructive testing; microscope photos; fiber volume fraction and void content. The evaluative requirements to detect the quality of radius fillers have been established and its validity has been confirmed by the R8 radius fillers.

Sign in / Sign up

Export Citation Format

Share Document