Novel Honeycomb Glassfiber Mat as the Core of Vacuum Insulation Panel

2014 ◽  
Vol 900 ◽  
pp. 247-250
Author(s):  
Cheng Dong Li ◽  
Zhao Feng Chen
Keyword(s):  
Thermal Insulation ◽  
High Performance ◽  
Three Dimensional ◽  
High Strength ◽  
Glass Wool ◽  
Core Material ◽  
The Core ◽  
Vacuum Insulation ◽  
Novel Structure ◽  
Chopped Strand Mat

Vacuum insulation panels (VIPs) are regarded as one of the most promising high-performance thermal insulation solutions on the market today. In this paper, a novel structure, i.e., honeycomb glassfiber mat was proposed as the core material of VIP. The honeycomb glassfiber mat was composed of glass wool mat and glassfiber chopped strand mat. Among them, 70% centrifugal glass wool and 30% flame attenuated glass wool were mixed together to form the 0.5mm-thickness glass wool mat, while thirteen holes with diameter of 10mm were opened uniformly on the surface of glassfiber chopped strand mat. Glassfiber VIPs possessed honeycomb core material have superior thermal conductivity of 1.52mW/(m•K). In order to obtain better thermal insulation performance, ultrafine and stiff fibers with three-dimensional overlapping structure is preferable. Meanwhile, hollow fibers with bifurcated structure are the guarantee of high-strength core material.

scholarly journals Thermal insulation properties of green vacuum insulation panel using wood fiber as core material

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3339-3351 ◽  
Author(s):  
Baowen Wang ◽  
Zhihui Li ◽  
Xinglai Qi ◽  
Nairong Chen ◽  
Qinzhi Zeng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bulk Density ◽  
Thermal Insulation ◽  
Wood Fiber ◽  
Core Material ◽  
High Porosity ◽  
Total Thermal Conductivity ◽  
Wood Fibers ◽  
Vacuum Insulation ◽  
Vacuum Insulation Panel

Wood fibers were prepared as core materials for a vacuum insulation panel (VIP) via a dry molding process. The morphology of the wood fibers and the microstructure, pore structure, transmittance, and thermal conductivity of the wood fiber VIP were tested. The results showed that the wood fibers had excellent thermal insulation properties and formed a porous structure by interweaving with one another. The optimum bulk density that led to a low-cost and highly thermally efficient wood fiber VIP was 180 kg/m3 to 200 kg/m3. The bulk density of the wood fiber VIP was 200 kg/m3, with a high porosity of 78%, a fine pore size of 112.8 μm, and a total pore volume of 7.0 cm3·g-1. The initial total thermal conductivity of the wood fiber VIP was 9.4 mW/(m·K) at 25 °C. The thermal conductivity of the VIP increased with increasing ambient temperature. These results were relatively good compared to the thermal insulation performance of current biomass VIPs, so the use of wood fiber as a VIP core material has broad application prospects.

Improving UV Resistance of Fibers: Idealized Computational Model Predicting the Distribution of UV Blocking Cylindrical Nanoparticles in Protective Polymeric Layer

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Abdelfattah Mohamed Seyam ◽  
Rahul Vallabh ◽  
Ahmed H. Hassanin
Keyword(s):  
Aspect Ratio ◽  
Computational Model ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Uv Protection ◽  
Uv Resistance ◽  
Premature Failure ◽  
Areal Coverage

High strength fibers such as PBO and Kevlar are used to produce composites, bulletproof vests, tendons of giant scientific balloons, and other high performance products. These fibers, however, are known to degrade upon exposure to Ultraviolet (UV) radiation which causes premature failure of the end-products. Improving UV resistance of high strength fibers like PBO through methods such as adding UV inhibiting particles during filament spinning or dyeing/coating process is not only extremely difficult, but often fails to provide the adequate UV protection. As an alternative to conventional approaches, UV protection of high performance yarns/braids can be effectively achieved by covering them with a polymeric sheath containing dispersed UV inhibiting nanoparticles. In this work, a computational model was developed to optimize critical factors such as thickness (weight) of the protective sheath and the amount of UV blockers for a given particle size, which influence the UV protective efficiency of the sheath. In order to simulate three-dimensional dispersion of nanoparticles in a polymer matrix, the model considers a random distribution of cylindrical nanoparticles of different size, aspect ratio, and volume fraction in a three-dimensional volume of protective sheath of a given length, width, and thickness. 2D visualization and image analysis techniques were utilized to determine the area projected by the particles on the x-y plane (areal coverage provided by nanoparticles). The areal coverage values obtained from the model were found to be higher than the experimental results due to the agglomeration of nanoparticles in the sheath caused during the polymer compounding process. However, the purpose of the model is to serve as a benchmarking tool to aid in the design and development of UV protective sheaths and films, and not to estimate absolute UV protection values. Analysis of the relationship between areal coverage and various input parameters in the model show that areal coverage increases with an increase in particle volume fraction and film thickness, and a decrease in particle diameter and length. It was also found that areal coverage was more significantly influenced by particle aspect ratio than by particle length.

Thermal Properties of Vacuum Insulation Panels with Glass Fiber

2012 ◽  
Vol 446-449 ◽  
pp. 3753-3756 ◽  
Author(s):  
Wang Ping Wu ◽  
Zhao Feng Chen ◽  
Jie Ming Zhou ◽  
Xue Yu Cheng
Keyword(s):  
Thermal Conductivity ◽  
Glass Fiber ◽  
Fiber Diameter ◽  
Core Material ◽  
The Core ◽  
Vacuum Insulation ◽  
Getter Effect ◽  
Porosity Ratio ◽  
Home Appliance ◽  
Heat Flow Meter

The VIPs consist of the glass-fiber core material and two types of envelope film. The glass fiber was fabricated by a centrifugal blowing process. The core material was prepared by the wet method. The thermal conductivities of the core material and VIPs were measured by the heat flow meter. The thermal conductivity for six pieces of 1mm thick core material is less than that for one piece of 6mm thick core material, which is affected by the fiber diameter, porosity ratio and the largest pore size diameter. The VIP for the building material has a low thermal conductivity (<0.008W/mK). The VIP for the home appliance has a lower thermal conductivity (<0.003W/mK). The VIP maintains a high-uniform thermal conductivity values due to the getter effect.

Core Materials of Vacuum Insulation Panels: A Review and Beyond

2012 ◽  
Vol 174-177 ◽  
pp. 1437-1440 ◽  
Author(s):  
Cheng Dong Li ◽  
Zhao Feng Chen ◽  
Wang Ping Wu ◽  
Zhou Chen ◽  
Jie Ming Zhou ◽  
...  
Keyword(s):  
High Performance ◽  
Insulation Material ◽  
Vacuum Insulation ◽  
Novel Structure ◽  
Powder Particles ◽  
Insulation Performance ◽  
Size Powder ◽  
Material Powder ◽  
Core Materials

Vacuum insulation panels (VIPs) are regarded as one of the most promising high performance thermal insulation solutions on the market today. The insulation performance of VIPs mainly depends on the quality of core materials. This paper compared three types of core materials, namely foam insulation material, powder insulation material and fibrous insulation material. Novel structure of core materials which is fiber pore structures packed with different size powder particles is also put forward on this paper. The aim of this paper is to investigate and compare various properties, requirements and possibilities for traditional core materials and put forward possible future core materials of VIPs.

A Methodology for Synthesizing High-Performance Robots Fabricated With Optimally Tailored Composite Laminates

1987 ◽  
Vol 109 (1) ◽  
pp. 74-86 ◽  
Author(s):  
C. K. Sung ◽  
B. S. Thompson
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Volume Fraction ◽  
Three Dimensional ◽  
High Strength ◽  
Fiber Volume ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Robot Arms ◽  
The Matrix

An essential ingredient of the next generation of robotic manipulators will be high-strength lightweight arms which promise high-performance characteristics. Currently, a design methodology for optimally synthesizing these essential robotic components does not exist. Herein, an approach is developed for addressing this void in the technology-base by integrating state-of-the-art techniques in both the science of composite materials and also the science of flexible robotic systems. This approach is based on the proposition that optimal performance can be achieved by fabricating robot arms with optimal cross-sectional geometries fabricated with optimally tailored composite laminates. A methodology is developed herein which synthesizes the manufacturing specification for laminates which are specifically tailored for robotic applications in which both high-strength, high-stiffness robot arms are required which also possess high material damping. The parameters in the manufacturing specification include the fiber-volume fraction, the matrix properties, the fiber properties, the ply layups, the stacking sequence and the ply thicknesses. This capability is then integrated within a finite-element methodology for analyzing the dynamic response of flexible robots. An illustrative example demonstrates the approach by simulating the three-dimensional elastodynamic response of a robot subjected to a prescribed spatial maneuver.

Progress on Vacuum Insulation Panels in Building Application

2012 ◽  
Vol 178-181 ◽  
pp. 46-50
Author(s):  
Wang Ping Wu ◽  
Zhou Chen ◽  
Cheng Dong Li ◽  
Teng Zhou Xu ◽  
Jin Lian Qiu ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Thermal Insulation ◽  
Surface Damage ◽  
Core Material ◽  
Insulation Material ◽  
Insulation System ◽  
Vacuum Insulation ◽  
Insulation Thickness ◽  
New Material ◽  
Barrier Film

The insulation material VIP in building offers a new material for highly insulated constructions with just a fraction of the required insulation thickness compared to conventional thermal insulation materials. A VIP is basically composed of the core material, the barrier film and getters. Core materials of VIP are glass fiber, fumed silica, fiber-powder composite core. The barrier film covered by glass fiber textile is the protection of the envelope against surface damage and fire attack. We introduce the VIP elements, the system of VIPs in building application and external thermal insulation system with VIP.

A Novel Rigid Vacuum Insulation Panel: Vacuum Insulation Sandwich

2012 ◽  
Vol 430-432 ◽  
pp. 741-745
Author(s):  
Juan Zhang ◽  
Zhao Feng Chen ◽  
Jie Ming Zhou ◽  
Bin Bin Li ◽  
Zhou Chen
Keyword(s):  
High Performance ◽  
Aluminum Film ◽  
Core Material ◽  
Atmospheric Gases ◽  
Detailed Structure ◽  
Rigid Barrier ◽  
Practical Applications ◽  
Vacuum Insulation ◽  
Gas Tight ◽  
Vacuum Insulation Panel

VIP (Vacuum insulation panel), as a high performance insulation component, combine with limited thickness, have recently been introduced to numerous energy conservation applications. VIP consists of a highly insulating core material and a gas tight barrier envelope which is generally composed of plastic film and aluminum film. When the envelope is stainless steel sheet, VIP is called VIS (vacuum insulation sandwich). Because of this hardly permeable rigid barrier, VIS presents more fantastic properties such as resistance against external mechanical loads and penetration of atmospheric gases and water vapor. Consequently, the service life of VIS is significantly longer than that of VIP. Detailed structure and some practical applications of VIS elements are also reviewed in this paper.

scholarly journals Pembelajaran Matematika dengan Media Software GeoGebra Materi Dimensi Tiga

2021 ◽  
Vol 10 (3) ◽  
pp. 449-460
Author(s):  
Syarifatul Maf’ulah ◽  
Suci Wulandari ◽  
Lia Jauhariyah ◽  
Ngateno Ngateno
Keyword(s):  
Learning Outcomes ◽  
Learning Process ◽  
Three Dimensional ◽  
Student Learning Outcomes ◽  
Learning Objectives ◽  
Core Material ◽  
The Core ◽  
Learning Mathematics ◽  
Before And After ◽  
Qualitative Descriptive

AbstrakKesulitan siswa dalam memahami materi dimensi tiga perlu diatasi. Misalnya dengan menggunakan bantuan media pembelajaran yang tepat seperti  Software GeoGebra. Penelitian bertujuan mendeskripsikan proses pembelajaran dan hasil belajar matematika menggunakan software GeoGebra. Penelitian deskriptif kualitatif ini terdiri dari 19 subjek kelas XII IPS salah satu MA swasta di Jombang. Instrumen penelitian yaitu lembar observasi, tes dan dokumentasi. Berdasarkan hasil penelitian diketahui bahwa proses pembelajaran dengan media software GeoGebra diawali dengan menyampaikan tujuan pembelajaran dan mengingatkan materi sebelumnya, menjelaskan unsur-unsur bangun ruang, memperkenalkan software GeoGebra, menjelaskan fungsi masing-masing menu, menjelaskan materi dimensi tiga menggunakan software GeoGebra, dan memberikan penguatan serta menyimpulkan inti materi yang telah dipelajari. Hasil penelitian lainnya menunjukkan bahwa terdapat perbedaan hasil belajar siswa yang signifikan antara sebelum dan sesudah pemanfaatan GeoGebra. Software GeoGebra cocok digunakan untuk membantu siswa memahami materi dimensi tiga dengan baik. Learning Mathematics with GeoGebra Software Media with Three-Dimensional MaterialAbstractStudents' difficulties in understanding three-dimensional material need to be overcome. For example, by using the help of appropriate learning media such as GeoGebra Software. The purpose of this research was to describe the learning process and learning outcomes of mathematics using GeoGebra software. This qualitative descriptive study consisted of 19 subjects of class XII IPS, one of the private MA in Jombang. The research instruments are observation sheets, tests, and documentation. Based on the results of the study, it is known that the learning process using the GeoGebra software media begins with conveying the learning objectives and reminding the previous material, explaining the elements of spatial structure, introducing the GeoGebra software, explaining the function of each menu, explaining the Three Dimensional material using the GeoGebra software, and closing with providing reinforcement and conclude the core material that has been studied. The results of other studies indicate that there are significant differences in student learning outcomes between before and after the use of GeoGebra. GeoGebra software is suitable to help students understand three-dimensional material well.

scholarly journals Hyperelastic modelling of yarn structures for dynamic applications

2018 ◽  
Vol 183 ◽  
pp. 01031
Author(s):  
Pietro del Sorbo ◽  
Jeremie Girardot ◽  
Frederic Dau ◽  
Ivan Iordanoff
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Weight Ratio ◽  
High Strength ◽  
Material Model ◽  
Linear Elastic ◽  
Mesoscopic Models ◽  
First Results ◽  
Hyperelastic Model ◽  
The Impact

Dry fabrics comprised of high performance polymeric fibers have been widely used as protection layers in structures submitted to high velocity impacts (HVI). Their outstanding impact energy dissipation ability combined with an high strength-to-weight ratio make them a preferable choice in different applications such as bullet vests or blade containment systems over standard materials. Among the different approaches adopted to study these structures numerical methods assume a central role. Thanks to their reduced costs and the related possibility of evaluating the effects of single phenomena, they are often used to predict the structure ballistic limits or to study the physical events which occur during the penetration. Among the different strategies adopted to model a fabric, mesoscopic models have been largely adopted by different authors. These models assume the yarns as a continuum body while the fabric geometry is explicitly described. Nowadays yarn material models are universally assumed to be linear elastic and orthotropic. This modelling approach mostly focuses on the longitudinal behaviour of the yarn, however fiber-scale analyses and experimental results shows the importance of three-dimensional stress state on the ballistic limit. In order to obtain a three-dimensional description of the yarn strain state during the impact, a novel hyperelastic model for yarn structures here is developed. In a first step, fiber-level preliminary analyses have been performed to obtain the effective behaviour of these structure under the projectile collision. In the second step, the hyperelastic model has been implemented and identified thanks to microscopic elementary tests. Finally, a continuum model of the yarn have been performed. First results show the relevance of the hyperelastic model compared to the fiber-level observation and enhance the limit of the classical linear elastic material model.

scholarly journals Combining Non-Uniform Time Slice and Finite Difference to Improve 3D Ghost Imaging

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 418 ◽  
Author(s):  
Fanghua Zhang ◽  
Jie Cao ◽  
Qun Hao ◽  
Kaiyu Zhang ◽  
Yang Cheng ◽  
...  
Keyword(s):  
Finite Difference ◽  
Traditional Method ◽  
High Performance ◽  
Three Dimensional ◽  
Field Of View ◽  
Time Slice ◽  
Ghost Imaging ◽  
Zero Crossing ◽  
Novel Structure ◽  
Differential Distance

Three-dimensional ghost imaging (3DGI) using a detector is widely used in many applications. The performance of 3DGI based on a uniform time slice is difficult to improve because obtaining an accurate time-slice position remains a challenge. This paper reports a novel structure based on non-uniform time slice combined with finite difference. In this approach, finite difference is beneficial to improving sensitivity of zero crossing to accurately obtain the position of the target in the field of view. Simultaneously, non-uniform time slice is used to quickly obtain 3DGI on an interesting target. Results show that better performances of 3DGI are obtained by our proposed method compared to the traditional method. Moreover, the relation between time slice and the signal-noise-ratio of 3DGI is discussed, and the optimal differential distance is obtained, thus motivating the development of a high-performance 3DGI.

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