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.

Effect of Envelope Films on Thermal Properties of Vacuum Insulation Panels with Glass Fiber

2011 ◽  
Vol 415-417 ◽  
pp. 859-864 ◽  
Author(s):  
Wang Ping Wu ◽  
Zhao Feng Chen ◽  
Jie Ming Zhou ◽  
Xue Yu Cheng
Keyword(s):  
Thermal Conductivity ◽  
Glass Fiber ◽  
Core Material ◽  
Type I ◽  
Type Ii ◽  
The Core ◽  
Vacuum Insulation ◽  
Porosity Ratio ◽  
Thermal Conductivities ◽  
Core Materials

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 materials were measured by the heat flow meter. The microstructure of the envelope film was observed by scanning electron microscopy. The porosity ratio and largest pore size diameters of the core materials are 92.27% and 20μm, respectively. The thermal conductivity of the VIP is about 8-10 times higher than that of the core materials. The thickness of type I and II envelope films are 45μm and 400μm, respectively. The thermal conductivities of the type I and type II envelope films are 0.11W/(m•K) and 0.69W/(m•K), respectively. The thermal conductivity of the VIP with type II envelope is higher than that of the VIP with type I envelope, which is attributed to the different structures and thickness of the envelope film.

Ultrafine Glass Fibers Produced by Centrifugal-Spinneret-Blow Process

2012 ◽  
Vol 628 ◽  
pp. 27-32 ◽  
Author(s):  
Zhou Chen ◽  
Xue Yu Cheng ◽  
Zhao Feng Chen ◽  
Juan Zhang ◽  
Yong Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Glass Fiber ◽  
Fiber Diameter ◽  
Raw Materials ◽  
Glass Fibers ◽  
Optical Microscope ◽  
Fiber Sample ◽  
Heat Flow Meter ◽  
Scanning Electron

In this paper, glass fibers were prepared by centrifugal-spinneret-blow(CSB)process. The diameter and microstructure of glass fibers have been investigated by scanning electron microscopy(SEM)and vertical optical microscope(VOM).The thermal conductivity and the thickness of glass fiber samples were determined by heat flow meter thermal conductivity instrumentation.The results indicated that the diameter of glass fibers prepared by CSB process can reach the ultrafine grade by adjusting the ratio of raw materials and process parameters.The thermal conductivity of glass fiber sample was 0.0298W/(m·K)when the diameter was 3μm and the density was 62kg/m3.The thermal conductivity of glass fiber sample decreased with the reduction of fiber diameter when the density of glass fiber sample is constant.

Preparation and characterization of vacuum insulation panels with super-stratified glass fiber core material

Energy ◽  
2015 ◽  
Vol 93 ◽  
pp. 945-954 ◽  
Author(s):  
Zhou Chen ◽  
Zhaofeng Chen ◽  
Zhaogang Yang ◽  
Jiaming Hu ◽  
Yong Yang ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Core Material ◽  
Fiber Core ◽  
Vacuum Insulation

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.

scholarly journals Composites with Excellent Insulation and High Adaptability for Lightweight Envelopes

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 53 ◽  
Author(s):  
Liang Guo ◽  
Wenbin Tong ◽  
Yexin Xu ◽  
Hong Ye
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Flow Direction ◽  
Base Material ◽  
Core Material ◽  
Insulation Materials ◽  
The Core ◽  
Cross Section Area ◽  
Heat Flow Direction ◽  
Section Area

Lightweight insulation materials are widely used in lightweight buildings, cold-chain vehicles and containers. A kind of insulation composite, which can combine the super insulation of state-of-the-art insulation materials or structures and the machinability or adaptability of traditional insulation materials, was proposed. The composite consists of two components, i.e., polyurethane (PU) foam as the base material and vacuum insulation panel (VIP) or silica aerogel as the core material. The core material is in plate shape and covered with the base material on all sides. The thermal conductivity of the core material is nearly one order lower than that of the base material. The effective thermal conductivity of the insulation composite was explored by simulation. Simulation results show that the effective thermal conductivity of the composite increases with the increase of the thermal conductivity of the core material. The effective thermal conductivities of the composites decrease with the increase of the cross-section area of the core material perpendicular to heat flow direction and the thicknesses of the core material parallel with heat flow direction. These rules can be elucidated by a series-parallel mode thermal resistance network method, which was verified by the measured results. For composite with a VIP as the core material, when the cross-section area and thickness of the VIP are respectively larger than 60% and 21% of the composite, the composite’s effective thermal conductivity can be 50% or less than that of the base material. Simulated heat loss of the envelope adopting the insulation composites with VIP as the core material is nearly a half of that of the envelope adopting traditional insulation materials.

Performance properties of vacuum insulation panels produced with various filling materials

2014 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Metin Davraz ◽  
Hilmi C. Bayrakci
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Glass Fiber ◽  
Fumed Silica ◽  
Production Costs ◽  
Unit Weight ◽  
Insulation Material ◽  
Core Samples ◽  
Vacuum Insulation ◽  
Precipitated Silica

AbstractVacuum insulation panel (VIP) is known to be the most effective insulation material. However, the usage areas of VIPs are restricted because of their high production costs. The core of VIP is the most important item affecting the cost of VIP. In this study, to obtain VIPs, which are provided with minimum thermal conductivity resistance value (R=5 m2 K/mW), was aimed for the optimal thickness of the panel (<40 mm). Therefore, 14 different core samples of VIP were produced by using various types of powders (fumed silica, precipitated silica, perlite, and diatomite), opacifiers (silicon carbide, carbon black, and titanium dioxide), and fibers (glass fiber, organic fiber, and cellulosic fiber). By using appropriate test methods, the physical properties of core samples such as unit weight, porosity, mass per volume and mechanical properties, their uniaxial compressive strength, tensile strength, and dimensional stability and also thermal conductivity coefficient in vacuum were determined. Results were compared with values of reference materials. The most appropriate compression pressure used in the manufacture of core sample was 27.5 kN. In addition, taking into account the benefit-cost relationship, the results of this study showed that the mix of fumed silica and precipitated silica (powder material), silicon carbide (opacifier), and glass fiber (fiber) was determined as the most suitable raw materials.

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.

The Applications of Vacuum Drying Technology in the VIP Core Material’ Pre-Treatment

2012 ◽  
Vol 472-475 ◽  
pp. 649-652 ◽  
Author(s):  
Zhong Cheng Wang ◽  
An Kang Kan
Keyword(s):  
Glass Fiber ◽  
Theoretical Study ◽  
Moisture Transfer ◽  
Core Material ◽  
Vacuum Drying ◽  
The Core ◽  
Gas Molecules ◽  
Water Vaporization ◽  
Pre Treatment ◽  
Drying Technology

This paper researched the mechanism and model of moisture transfer in the core material of VIP- glass fiber, and introduced the vacuum drying technology to enhance the gas molecules’ movement under vacuum, accelerate the speed of water vaporization and avoid voids adhesion to overcome the adsorption resistance. The article also designed the equipment to provide experimental possibilities for the theoretical study.

scholarly journals Bonding of Core Build-Up Composites with Glass Fiber-Reinforced Posts

2019 ◽  
Vol 7 (4) ◽  
pp. 105 ◽  
Author(s):  
Margarita Fragkouli ◽  
Ioannis Tzoutzas ◽  
George Eliades
Keyword(s):  
Glass Fiber ◽  
Tensile Force ◽  
Core Material ◽  
Mode Analysis ◽  
Fiber Reinforced ◽  
The Core ◽  
Glass Fiber Reinforced ◽  
Significant Difference ◽  
Failure Mode Analysis ◽  
Material Fracture

The purpose of this study was to investigate the bonding capacity of composite core build-up materials with prefabricated glass fiber-reinforced posts possessing different coronal morphologies. Five post types (Archimede Line (ARL), Fibrekleer (FBK), Glassix (GLX), Matrix Plus (MTP), and ParaPost White (PRW) and three core build-up materials (ClearfilPhoto Core (CPC), ClearfilDC Core (CDC), ClearfilNew Bond (CNB) of different curing modes (light-, self-, dual-cured respectively) were selected. The coronal part was embedded in the core build-up materials and the specimens were loaded under tensile force up to failure. The reliability (β) and characteristic life (σο, in Ν) of the debonding force were evaluated by Weibull statistics and the debonded specimens were subjected to failure mode analysis. The results showed that ARL, MPT posts were the most and GLX the least retentive, despite the core build-up material used. CPC provided the highest retention with four posts (FBK, GLX, MTP, and PRW), without statistically significant differences from CDC in two (FBK and MTP) and CNB in one (PRW). CPC and CDC were the most reliable core materials for two posts (ARL and PRW), with no statistically significant difference from CNB in three (FBK, GLX, and MTP). GLX and PRW demonstrated the highest (93%) incidence of post detachment from core, whereas FBK demonstrated the highest percentage of core material fracture, with most fractures occurring in CDC (57%). Post fractures were most prominent in MTP when combined with CNB. The presence of specific coronal retentive features did not essentially ensure increased strength with the core material, due to their delamination.

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