Jie Ming Zhou

Thermal Properties of Vacuum Insulation Panels with Glass Fiber

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

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.

Vacuum Insulation Panel for Green Building

Vacuum insulation panel is regarded as one of the most promising high performance thermal insulation materials for green building. It has extremely low thermal conductivity and its insulation performance is a factor of four to eight times better than that of conventional insulation such as mineral wool or polymer foams. The high thermal resistivity of VIP provides new solutions for slim but still energy efficient building envelopes. Although VIP has widely been used in refrigerators and freezers for a long time, it has only recently been discovered by the building sector. There is not yet any alternative for conventional thermal insulation materials in many countries, especially in China. This paper attempts to investigate the components, features and advantages of VIP for building, it will be helpful to the development of green building.

Glass Wool Prepared under Various Rotating Speed by Centrifugal-Spinneret-Blow Process

In this paper, glass wool has been prepared under various rotating speed of centrifugal pan by centrifugal-spinneret-blow process. The fiber diameter of glass wool has been studied by scanning electron microscopy (SEM) and vertical optical microscope (VOM). With the increase of rotating speed from 1800 rpm to 2400 rpm, the mean fiber diameter decreased from 5.9 µm to 3.9 µm, indicating the distribution of glass wool becomes more uniformity. The results show that the rotating speed has a direct and pronounced effect on the fiber diameter and distribution. The higher the rotating speed is, the smaller the mean fiber diameter is, and the more uniformity the distribution of fiber diameter is.

Ultrafine Glass Fiber Core Material Produced by Wet Method

Glass fibers have non-flame, non-toxic, antisepsis, light volume-weight, low heat conduction factor, good chemistry stability, low water absorption coefficient and good hydrophpbic coefficient. In this paper, ultrafine glass fiber core material was produced by wet method. Performances of ultrafine glass fiber core material and VIP were introduced. The thermal conductivities of ultrafine glass fiber core material is about 0.02966 W/(m•K). Ultrafine glass fiber core material with about 92%-98% porosity ratios makes it easy to reach high vacuum degree for VIP. The thermal insulating capacity of VIP is about 10 times higher than that of conventional insulating materials. Ultrafine glass fiber core material is ideal core material for VIP.

Material Parameter Determination in Glass Wool Mat for Sound Absorption

Glass wool mat is widely used in the fields of building engineering, transport facilities and refrigeration equipment. In this paper, the effect of material parameters such as density, thickness, porosity, and flow resistivity on the normal incidence absorption coefficient has been studied. In addition, fiber length is also investigated to achieve appropriate strength. The prediction error of normal incidence absorption coefficient by modified Johnson–Allard model is less than 5% in the frequency range between 800 Hz and 5 kHz. We could use the modified Johnson–Allard model to determine the parameter of glass wool mat for better development.

Glass Fibers as Engineering Materials

Glass fibers feature extremely low thermal conductivity, high modulus, high toughness, light weight and non-combustible property. These materials can work in situations in which plastics and metals would fail and need to be part of designer’s repertoire. They have many applications in design engineering and can solve many special problems. This paper contains a number of chapters as follows: introduction to glass fibers, manufacturing processes of glass fibers, markets and applications of glass fibers. The conclusion of this paper contains some strategic lines of glass fibers usage in industry and estimations about the future development of glass fibers.

Effect of Vitreous Fluid Temperature on Fiber Diameter and Surface Topography of Glass Wool by Centrifugal-Spinneret-Blow Process

In this paper, glass wools were prepared under different vitreous fluid temperature (vary from 1100oC to 1300oC) by centrifugal-spinneret-blow process. The effect of vitreous fluid temperature on fiber diameter and surface topography of glass wool has been studied by Scanning Electron Microscopy and Vertical Optical Microscope. With the increase of vitreous fluid temperature (T) from 1100oC to 1250oC, the mean fiber diameter decreased from 6.6µm to 3.9µm. When vitreous fluid temperature goes up to 1300oC, the mean fiber diameter increased to 4.1µm, slightly bigger than that of 1250oC. There are many protuberances in the fiber for T=1100oC and 1150oC because the surface tension is very strong at low temperature. The surface topography of fiber becomes smooth when the temperature is higher than 1200oC. The results show that the vitreous fluid temperature has a direct and pronounced effect on fiber diameter and surface topography. The optimum vitreous fluid temperature is about 1250oC.

Progress on Vacuum Insulation Panels in Building Application

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

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.