Insulation Board Research Articles

Study of the surfactant role in latex–aerogel systems by scanning transmission electron microscopy on aqueous suspensions

For insulation applications, boards thinner than 2 cm are under design with specific thermal conductivities lower than 15 mWm-1 K-1 . This requires binding slightly hydrophobic aerogels which are highly nanoporous granular materials. To reach this step and ensure insulation board durability at the building scale, it is compulsory to design, characterise and analyse the microstructure at the nanoscale. It is indeed necessary to understand how the solid material is formed from a liquid suspension. This issue is addressed in this paper through wet-STEM experiments carried out in an Environmental Scanning Electron Microscope (ESEM). Latex-surfactant binary blends and latex-surfactant-aerogel ternary systems are studied, with two different surfactants of very different chemical structures. Image analysis is used to distinguish the different components and get quantitative morphological parameters which describe the sample architecture. The evolution of such morphological parameters during water evaporation permits a good understanding of the role of the surfactant.

The environmental impact of phenolic foam insulation boards

The use of external wall insulation is on the increase, with phenolic foam being a popular insulation choice. However, if designers are to make informed decisions on material choices, the environmental impact of the insulation should be considered and the payback period of the associated impacts evaluated. There is a lack of information for phenolic foam insulation; this paper seeks to fill this gap. Results are given utilising the international reference life-cycle data system methodology to ensure they are easily comparable and can be used in other studies. Considering the whole life cycle, the impacts from water depletion and freshwater ecotoxicity see the longest payback times; these are recommended for targeted reduction.

Construction method of foam glass thermal insulation material in sloping roof

Foam glass thermal insulation board has the characteristics of fireproof, waterproof, corrosion resistant, noncombustible, mothproof, non-toxic, non-aging, non-radioactive, high mechanical strength and good dimensional stability. Foam glass thermal insulation material in sloping roof construction method is an effective solution to large angle sloping roof construction operation difficulties.

The Study of Adding Heat Insulation Baffle on the Heat Transfer Performance of the Vertical U-shaped Ground Tube Heat Exchanger

Vertical single U-shaped ground tube is presented in this paper based on the research of the three-dimensional heat transfer model, using the numerical simulation method to study Nanjing area in summer conditions ground heat exchanger. Under the condition of not adding insulation board, comparing the influence of different inlet velocity on the heat exchanger, and then compared the adding different length of insulation surface heat exchanger heat transfer capacity, the influence of the comparative analysis of the results show that the inlet velocity under different operating conditions and the influence on the buried pipe outlet temperature and heat transfer, adding heat shield does not necessarily slow down the hot short circuit, so the heat exchanger, heat transfer performance and fuel economy must be considered to choose the best length of insulation board.

Elastic properties of packing of granulated cork: Effect of particle size

Cork is a natural raw materials used in numerous traditional and innovative applications among which the most famous are cork stoppers, insulation boards, and wall and floor covering. Cork exhibits a relatively homogeneous honeycomb structure composed of polyhedron cells filled with gas, which gives its specific properties such as elasticity or hydrophobic behavior. Mechanical properties of cork have been studied from a long time. However, in many industrial applications cork is increasingly used as granulate (>200μm) or powder (<200μm) obtained by milling processes. By generating failure in the raw material, the comminution of cork could damage cells and induce modifications in the mechanical behavior of cork particles but the relation between the size of the particles and the mechanical properties of the packaging is still little known. In this study, we investigate the effect of cork particles size reduction on the mechanical properties of the packing. To this end, eighteen discrete size fractions of cork from 0 to 25μm to 2.5–3mm, generated by impact milling were characterized in term of shape, loaded density, and elastic recovery. Experiments show that impact milling mainly affects the elastic properties of particles less than 200μm. The mechanical behavior of cork particles was also described by model based on a mixing law taking in account the size and the shape of particles and the amount of damaged cells in the particles. The fitting of the model to the experimental data suggests that the elastic properties of the packing of cork particles have to be related to the content of damage cells more than to their size.

Influence of Structure on Thermal Conductivity of Insulation Board Used during Ingot Casting

In order to improve heat prevention property of insulation board used in hot top during casting of steel ingot, thermal conductivities of insulation boards of solid structure and porous structure with different porosities were investigated using numerical simulation and calorimetric techniques. A heat transfer model used to calculate the thermal conductivity of insulation boards was developed, and the accuracy of the model was verified by calorimetric experiment. A series of porous insulation boards made of floating beads with different porosities were designed and effect of porosity on thermal conductivity of porous insulation board was investigated by numerical simulation. It was found that porous insulation board performs a better heat prevention property than insulation board of solid structure. Thermal conductivity of porous insulation board decreases notably with the increase of porosity. By contrast, the sizes of pores almost have no influence on the thermal conductivity of porous insulation board.

Effect of Surface Vitrification on the Properties of Insulation Board of Expanded Perlite

The surface-vitrified and expanded perlite is a new, high-quality insulation materials. It is studied to the effects on performances of the glass surface to expanded perlite insulation board, through comparing with the openings of expanded perlite, expanded and vitrified small ball and surface-vitrified and expanded perlite. A large number of experiments have been done on the physical properties of the insulation board with surface-vitrified and expanded perlite. It shows that the insulation board with surface-vitrified and expanded perlite has a low density, high strength, low water absorption, high obturator rate, low thermal conductivity, stable performance and so on. And the main reason is analyzed.

Thickness Determination of a Three-layer Wall with Phase Change Materials in a Chinese Solar Greenhouse

Chinese solar greenhouse (CSG) is an energy saving production building that used to grow vegetables in winter. The north wall of CSG plays an important role concerning the vegetable production without additional heating during the winter months. This paper studies a north wall of a CSG which is built with three layers, the phase-change material wallboard/the block brick /the insulation board. To determine the optimum thickness of the three-layer wall for passive solar heating, a solar greenhouse model is constructed by Energy Plus v8.6 to study the dynamic heat storage/release characteristics of the wall and develop methods to estimate its thickness. The results show that the optimum thicknesses of the phase-change material wallboard, the block brick and the insulation board of the expanded polystyrene in Beijing are about 50 mm, 620 mm and 60 mm, respectively. The results can provide reference for the optimization design and thermal performance analysis of solar greenhouse.

Analysis and Aesearch of White Spot on Creepage Discharge in oil-Pressboard Interface

Creepage discharges on oil impregnated pressboard is one of the most dangerous transformer insulation fault, which can cause the gas action even transformer housing cracking accident. “White spot” is creepage important phenomena in the process of insulation board along the surface, so it is necessary to study the insulation board along the surface of creepage “white spot” in the process of growth characteristics. This paper set up a insulating paper along the surface of creepage “white spot” in the process of growth characteristics of observation platform. Numerical example was calculated under different aging degree creepage cardboard along the surface of the “white spot” in the process of change, statistics and analysis of the “white spot” length, angle and size variation, which is very practical to the production practice.

Thermal performance of precast light floor radiant panel

Precast light floor radiant panel is an integrated sheet which consists of insulating base board, heating plastic tube, thick aluminum foil and surface course. The heating tube is laid in the groove of insulation board under aluminum foil. The radiant panel is simplified as a two-dimensional heat transfer model for analysis. The numerical simulation is carried out to obtain the thermal performance. Experiments are conducted to verify the simulation. The average temperature of the inner wall of the heating tube and the surface of the aluminum foil under steady state was measured, and the thermal resistance under the experimental conditions was obtained. Comparisons between the experimental results and the simulation results indicate that the simulation is valid. The effects of different tube spacing and thickness of aluminum foil on the surface temperature and the equivalent thermal resistance of the radiant panel is studied by simulations. The results show that the distance between heating tubes has obvious effect on the equivalent thermal resistance, while the thickness of aluminum foil has insignificant influence on the thermal performance of the heating panel in question.

Effect of Moisture Content on Thermal Properties of Porous Building Materials

The thermal conductivity and specific heat capacity of characteristic types of porous building materials are determined in the whole range of moisture content from dry to fully water-saturated state. A transient pulse technique is used in the experiments, in order to avoid the influence of moisture transport on measured data. The investigated specimens include cement composites, ceramics, plasters, and thermal insulation boards. The effect of moisture-induced changes in thermal conductivity and specific heat capacity on the energy performance of selected building envelopes containing the studied materials is then analyzed using computational modeling of coupled heat and moisture transport. The results show an increased moisture content as a substantial negative factor affecting both thermal properties of materials and energy balance of envelopes, which underlines the necessity to use moisture-dependent thermal parameters of building materials in energy-related calculations.

Hygric characterization of wood fiber insulation under uncertainty with dynamic measurements and Markov Chain Monte-Carlo algorithm

The present work is the hygric characterization of wood fibre insulation boards, using dynamic measurements of relative humidity and sample weight, analyzed in the frame of Bayesian inference for parameter identification under uncertainty. It is an attempt at identifying detailed profiles of moisture-dependent properties, and thus a relatively high number of parameters. Because of this ambition, some caution should be exercised once the outcome of the inversion algorithm is available: in addition to confidence intervals of parameters provided by the Bayesian framework, a simplified form of identifiability analysis is performed by analysing a posteriori parameter correlations and likelihood-based confidence intervals.The characterization methodology does not require for the model structure to have a differentiable analytical formulation, or for material samples to reach mass equilibrium between each RH step of the experimental process. Two separate experimental designs were used for material characterization and for validation, respectively. Results show a clear relation between available information (experimental data) and inference (confidence intervals of parameters). A single relative humidity step is not informative enough for a precise inference of moisture-dependent properties such as vapour permeability and moisture capacity. A two-step experiment however holds enough information to significantly reduce parameter uncertainty.

Foam Concrete Gravity Wedges as a Thermal Insulation of Flat Roofs

Proper selection of thermal insulation materials is an essential part of almost any construction project, whether it is a new construction, renovation or revitalization. There is a large number of materials available on the market and it is often very difficult to have a good grasp. Though some material has very similar features, they often cannot replace each other. The same applies to single-shell flat roofs. So far the most often used thermal insulation boards are from polystyrene and mineral wool. Their installation is accompanied by a large volume of waste. The experimental part deals with the general assessment of the behavior and properties of foam concrete. This allows simplification of technology of thermal insulation laying. Besides the construction speed up and the overall cost reduction the improvement in mechanical properties of the roof structure has been achieved.

Thermal Insulation Boards from Bamboo Paper Sludge

This study was conducted to evaluate the properties of insulation boards made from bamboo paper sludge and fly ash floating beads. An orthogonal test design was applied to study the effects of certain factors on the properties of the insulation boards. The results indicated that the sequence of significant effect of factors on the properties of the composite boards was particle size of bamboo paper sludge, thickness of boards, and weight ratio of sludge to fly ash floating beads. The verified optimal conditions were confirmed to be 20 to 40 mesh, 80:20, and 14 mm, representing the particle size of bamboo paper sludge, weight ratio of sludge:fly ash floating beads, and thickness of boards, respectively. The thermal conductivity of the bamboo paper sludge and fly ash floating beads insulation boards was measured and suggested that both insulation boards had thermal conductivity values ranging from 0.12 to 0.165 W/mK, which is close to the conventional insulation material lightweight concrete.

Development of medium- and low-density fibreboards made of coconut husk and bound with tannin-based adhesives

Fibreboards made of coconut husk and bonded with tannin-based adhesives could represent an affordable building material in the Philippine for the low-income population. Coconut husk is a large available and not full-exploited byproduct of the coconut industry, and suitable tannins could be extracted from the bark of local tree species. Medium-density boards (700–800 kg m−3) were produced at the lab-scale and the influence of pressing cycle parameters, material preconditioning, and tannin adhesive formulation investigated and correlated to the chemical characteristics of the husk. Mimosa tannin adhesives with and without hardener (hexamine) and at different pH were considered. The produced board satisfied the mechanical requirements for the Japanese standard JIS A 5905 (Type 15) and showed also remarkably low-volatile emissions. An initial moisture content of the husk between 9 and 15% was necessary for an efficient adsorption of the adhesive. The presence of silica on the fibre surface enhanced the auto-condensation of tannin molecule reducing the need of hardener in the adhesive formulation. Low-density boards (250–300 kg m−3) were also produced. Their thermal conductivity (0.071–0.082 W m−2K−1) satisfied the requirement for JIS A 5905 Class A insulation boards.

A simple centerline extraction approach for 2D polygons

T his paper describes a new two task approach for extracting the centerline from simple 2D polygons. An algorithm of the first task, which generates a set of points for future centerline, is presented. The idea of the algorithm is to use the polygon hatching by parallel lines and creating paths from its middle points in different polygon rotations. The centerline is derived from the intersection points between these paths. The algorithm was developed for printed circuit board insulation process and its execution time for a few hundred polygons is less than one second. The algorithm is easy to understand and implement. DOI: http://dx.doi.org/10.5755/j01.itc.45.3.12964

Environmental Footprint of External Thermal Insulation Composite Systems with Different Insulation Types

In terms of upcoming energy directive for Nearly Zero Energy Houses (nZEB), we are very much focused on building skin and its properties. Not only thermal characteristics and design, but also durability and environmental aspects should play a role, when deciding on which system will be implemented. External Thermal Insulation Composite Systems or ETICS are generally made of adhesive, insulation, render with mesh reinforcement, primer and finish coat. In the following case study we have presented a life cycle assessment (LCA) study of three ETICS with different types of insulation: expanded polystyrene (EPS), mineral wool and wood fiber board insulation. The study complies to the standard EN 15804:2012. It was conducted in the program Gabi using the Gabi Professional 2012 Database. The scope of the study is covering the production phase (raw material supply, transport to the factory, manufacturing). We have compared the functional unit of 1 sqm of the ETICS system with U-value 0.27W/m2K taking into account different environmental impact categories. In the calculation the characterization factors proposed by Centre of Environmental Science (CML) at Leiden University were used. The comparison of ETICS shows the important impact of the insulation type used. Also there are some differences in the amount of other ETICS components applied, since changing the type of insulation affects the environmental footprint of the ETICS.

Investigation of the interrelations between defibration conditions, fiber size and medium-density fiberboard (MDF) properties

Defibration conditions and raw material properties affect wood fiber characteristics, and thereby the properties of fiber-based panels such as high-density fiberboard (HDF), medium-density fiberboard (MDF) and wood fiber insulation board. This study investigates the influence of steaming conditions (time and temperature), grinding disc distance, wood species (pine, beech, birch and poplar), method of refiner discharging (radial and tangential stock outlet) and wood chip size on fiber length and fiber length distribution, and further the influence of fiber size on MDF properties. Fiber lengths were determined applying the recently developed image analysis-based fiber size measuring system FibreCube. This system enables an automated and nearly complete mechanical separation of woolly-felted fiber samples prior to image acquisition, software-supported post-separation of overlapped-lying fibers at the beginning of image analysis, and flow line tracing-based length measurement. It was found that grinding disc distance and wood species are the most influential parameters on fiber length characteristics. Especially the content of undefibrated fiber bundles (shives) was found to strongly correlate with the grinding disc distance. Wood anatomical differences between hardwood and softwood were reflected clearly by the fiber length characteristics. Fiber size was found to be one of the parameters influencing panel properties. However, other fiber characteristics—in particular the chemical nature of the fiber, which is responsible for its wettability with water (thickness swelling) and glue (mechanical properties)—have to be considered as important influencing parameters on panel properties.

Effect of plaster thickness on performance of external thermal insulation cladding systems (ETICS) in buildings

In a properly designed and constructed building, insulating material contributes enormously to energy savings for the heating and cooling of buildings (about 60%). On the other hand, there is always the possibility of fire in buildings. Insulation materials mostly used in Turkey are expanded polystyrene foam (EPS), extruded polystyrene (XPS) and rock-wool (RW). RW is the best durable materials to fire, however it is expensive. EPS and XPS start to soften at low temperatures (about 80°C). This is not only financial losses but also a contribution to CO2 and global warming. For the study, tests conducted to determine combustion characteristics of insulation boards with different plaster thicknesses of 2, 4, 6 and 8mm. They were exposed to ignition by a single flame test setup on the front surface. Moreover, the ignition time on the insulation boards was gradually increased from 0.5min to 25min. At the end of tests, burnt length and burnt volume of EPS boards behind plaster on the specimen surface were measured. Results showed that in practical engineering, all types of boards except for RW, must be used as insulating materials with at least 4mm plaster for the lowest combustion and hazard. The optimum thickness is measured as 6mm for all the coatings.

Influence of suspended particles on the emission of organophosphate flame retardant from insulation boards.

The influence of the presence of the so-called seed particles on the emission rate of Tris (1-chloroisopropyl) phosphate (TCIPP) from polyisocyanurate (PIR) insulation boards was investigated in this study. Two Field and Laboratory Emission Test cells (FLEC) were placed on the surface of the same PIR board and respectively supplied with clean air (reference FLEC) and air containing laboratory-generated soot particles (test FLEC). The behavior of the area-specific emission rates (SER A ) over a time period of 10days was studied by measuring the total (gas + particles) concentrations of TCIPP at the exhaust of each FLEC. The estimated SER A of TCIPP from the PIR board at the quasi-static equilibrium were found to be 0.82μgm(-2)h(-1) in the absence of seed particles, while the addition of soot particles led to SER A of 2.16μgm(-2)h(-1). This indicates an increase of the SER A of TCIPP from the PIR board with a factor of 3 in the presence of soot particles. The TCIPP partition coefficient to soot particles at the quasi-static equilibrium was 0.022 ± 0.012m(3)μg(-1). In the next step, the influence of real-life particles on TCIPP emission rates was investigated by supplying the test FLEC with air from a professional kitchen where mainly frying and baking activities took place. Similar to the reference FLEC outcomes, SER A was also found to increase in this real-life experiment over a time period of 20days by a factor 3 in the presence of particles generated during cooking activities. The median value of estimated particle-gas coefficient for this test was 0.062 ± 0.037m(3)μg(-1).