scholarly journals Physical and thermal characterizations of insulation composite made of wood fibers

2021 ◽  
Author(s):  
◽  
Tianxiao Hu

Currently, mineral fiber or cellular plastic insulation materials dominate the building construction market because of their relatively competitive price and low thermal conductivity properties; however, the environmental impacts of cellular plastic insulation materials during their whole life cycle are significantly higher. Additionally, the forestry sector in Canada generates approximately 5.38 × 106 oven-dried tons of wood product residues per year and there are opportunities to further process and use them as the raw materials for producing wood-based fiber insulation boards. The purpose of this study is to investigate the methods to utilize the woody residues and process them into wood fibers to form insulation boards. Additionally, an eco-friendly casein adhesive was chosen to bind the wood particles together. The boards were successfully formed and have thermal conductivity values ranging from 0.057 to 0.078 W/mK, based on different board densities and moisture contents, which satisfy the minimum requirement of the ASTM insulation standard. Thus, this study of forming wood-based fiber insulation boards shows opportunities of reducing the environmental impacts and reducing the building energy consumption due to heating or cooling at the same time.

2014 ◽  
Vol 604 ◽  
pp. 285-288 ◽  
Author(s):  
Saulius Vaitkus ◽  
Rūta Karpavičiūtė ◽  
Sigitas Vėjelis ◽  
Lina Lekūnaitė

Natural fibres from flax and hemp are used as raw materials for efficient thermal insulation. In current work, tests were carried out using chopped and combed long flax fibres as well as chopped and combed long hemp fibres. Investigations have shown that thermal conductivity of natural fibres depends on their preparation method (combing, chopping) and materials density.


2013 ◽  
Vol 662 ◽  
pp. 331-334
Author(s):  
Huan Qi Zhao ◽  
Guo Zhong Li

Cement-based lightweight insulation materials were made. Cement and fly ash are main raw materials. The self-developed composite excitation agent and foaming agent are used. The method of foaming is the physical foaming. The inflection of fiber dosage on the performance of lightweight insulation materials was researched. Its influencing mechanism was discussed. Experiments show that foaming lightweight insulation materials were made with 1.22MPa bending strength, 2.95MPa compressive strength and the 0.072W/mk coefficient of thermal conductivity when the fiber mixing content is 1.2%.


2013 ◽  
Vol 327 ◽  
pp. 40-43
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li

The ordinary portland cement was used to prepare foamed cement insulation materials by physical foaming method. The influence of different process of fiber added to the foamed cement insulation materials on its performance was studied and the optimum mix ratio of raw materials was determined. The results showed that the glass fire could be evenly dispersed in the slurry by dry adding technology and got better enhanced effect. When the dosage of glass fire was 0.9%, the performance of the foamed cement material as follows: dry density of 318 kg/m3, 3d flexural strength of 0.61MPa, 3d compressive strength of 1.05MPa, thermal conductivity of 0.065W/(m·k). The reinforce mechanism of glass fire was explored.


1970 ◽  
Vol 17 (2) ◽  
pp. 208-212 ◽  
Author(s):  
Jolanta VĖJELIENĖ ◽  
Albinas GAILIUS ◽  
Sigitas VĖJELIS ◽  
Saulius VAITKUS ◽  
Giedrius BALČIŪNAS

The development of new thermal insulation materials needs to evaluate properties and structure of raw material, technological factors that make influence on the thermal conductivity of material. One of the most promising raw materials for production of insulation material is straw. The use of natural fibres in insulation is closely linked to the ecological building sector, where selection of materials is based on factors including recyclable, renewable raw materials and low resource production techniques In current work results of research on structure and thermal conductivity of renewable resources for production thermal insulating materials are presented. Due to the high abundance of renewable resources and a good its structure as raw material for thermal insulation materials barley straw, reeds, cattails and bent grass stalks are used. Macro- and micro structure analysis of these substances is performed. Straw bales of these materials are used for determining thermal conductivity. It was found that the macrostructure has the greatest effect on thermal conductivity of materials. Thermal conductivity of material is determined by the formation of a bale due to the large amount of pores among the stalks of the plant, inside the stalk and inside the stalk wall.http://dx.doi.org/10.5755/j01.ms.17.2.494


2020 ◽  
Vol 24 (5 Part B) ◽  
pp. 3195-3203
Author(s):  
Jianying Wang

In order to reduce the energy efficiency of the construction industry and improve the building safety, in this research, a new type of inorganic insulation material ? vitreous bead insulation mortar is studied and its properties are analyzed. Quantitative method is used to analyze the influence of glass bead mixing amount, cellulose ether mixing amount and redispersible emulsion powder mixing amount on the consistency, water retention rate, dry density, softening coefficient and compressive strength of glass bead insulation mortar. The effect of different raw materials allocation on the thermal conductivity of vitrified microbeads thermal insulation mortar is explored. The results show that the performance of insulation mortar decreases significantly with the increase of glass bubbles. With the increase of cellulose ether content, the consistency and compressive strength of insulation mortar first increased and then decreased, the water retention rate increased significantly, but the dry density decreased significantly. With the increase of the content of redispersible emulsion powder, the consistency and compressive strength of insulation mortar first increased and then decreased, but the dry density decreased gradually. Glass bubbles and fly ash parameters are the main factors that affect the thermal conductivity of thermal insulation mortar, and their thermal conductivity decreases with the increase of the proportion of air-entraining agent. As a result, the performance of vitreous microbeads thermal insulation mortar will change to a certain extent with the different proportion of raw materials, which provides data support for the preparation and application of inorganic external wall thermal insulation materials.


2018 ◽  
Vol 27 (4) ◽  
pp. 096369351802700 ◽  
Author(s):  
Mehmet Önal ◽  
Gökdeniz Neşer

Glass reinforced polyester (GRP), as a thermoset polymer composites, dominates boat building industry with its several advantages such as high strength/weight ratio, cohesiveness, good resistance to environment. However, proper recovering and recycling of GRP boats is became a current environmental requirement that should be met by the related industry. In this study, to propose in a cost effective and environmentally friendly way, Life Cycle Assessment (LCA) has been carried out for six scenarios include two moulding methods (namely Hand Lay-up Method, HLM and Vacuum Infusion Method, VIM) and three End-of-Life (EoL) alternatives(namely Extruding, Incineration and Landfill) for a recreational boat's GRP hulls. A case study from raw materials purchasing phase to disposal/recycling stages has been established taking 11 m length GRP boat hull as the functional unit. Analysis show that in the production phase, the impacts are mainly due to the use of energy (electricity), transport and raw material manufacture. Largest differences between the methods considered (HLM and VIM) can be observed in the factors of marine aquatic ecotoxicity and eutrophication while the closest ones are abiotic depletion, ozon layer depletion and photochemical oxidation. The environmental impact of VIM is much higher than HLM due to its higher energy consumption while vacuum infusion method has lower risk than hand lay-up method in terms of occupational health by using less raw material (resin) in a closed mold. In the comparison of the three EoL techniques, the mechanical way of recycling (granule extruding) shows better environmental impacts except terrestrial ecotoxicity, photochemical oxidation and acidification. Among the EoL alternatives, landfill has the highest environmental impacts except ‘global warming potential’ and ‘human toxicity’ which are the highest in extrusion. The main cause of the impacts of landfill is the transportation needs between the EoL boats and the licenced landfill site. Although it has the higher impact on human toxicity, incineration is the second cleaner alternative of EoL techniques considered in this study. In fact that the similar trend has been observed both in production and EoL phases of the boat. It is obvious that using much more renewable energy mix and greener transportation alternative can reduce the overall impact of the all phases considerably.


2021 ◽  
pp. 002199832110316
Author(s):  
Nuno Gama ◽  
B Godinho ◽  
Ana Barros-Timmons ◽  
Artur Ferreira

In this study polyurethane (PU) residues were mixed with residues of textile fibers (cotton, wool and synthetic fibers up to 70 wt/wt) to produce 100% recycled composites. In addition, the effect of the type of fiber on the performance of the ensuing composites was evaluated. The presence of fibers showed similar effect on the density, reducing the density in the 5.5-9.0% range. In a similar manner, the addition of fillers decreased their thermal conductivity. The 70 wt/wt wool composite presented 38.1% lower thermal conductivity when compared to the neat matrix, a reduction that was similar for the other type of fibers. Moreover, the presence of fillers yields stiffer materials, especially in the case of the Wool based composites, which with 70 wt/wt of filler content increased the tensile modulus of the ensuing material 3.4 times. This was attributed to the aspect ratio and stiffness of this type of fiber. Finally, the high-water absorption and lower thermal stability observed, especially in the case of the natural fibers, was associated with the hydrophilic nature of fibers and porosity of composites. Overall, the results suggest that these textile-based composites are suitable for construction and automotive applications, with the advantage of being produced from 100% recycled raw-materials, without compromised performance.


Author(s):  
Marcela Spišáková ◽  
Mária Kozlovská ◽  
Jozef Švajlenka

Construction industry creates an environment for people's lives. On the other hand, construction activities have a negative impact on various aspects of the environment. It consumes natural raw materials, significantly contributes to carbon footprint, waste, etc. Appropriate choice of constructional, material, technical, technological and environmental parameters of buildings can partially reduce this negative impacts. By designing, implementing and using wood-based constructions it is possible to reduce the negative impact in the area of construction waste generation. Currently, the construction market offers a large number of construction systems of wooden buildings, which have both strengths and weaknesses. In this paper are identified construction systems of wooden buildings offered on the Slovak construction market. The aim of the paper is a detailed identification of construction waste generation during the realization of particular wooden structures and monitoring of waste generation in production factory (off site) and on construction site (on site) during the construction of wooden buildings. Based on the obtained information, the individual construction systems of wood-based constructions are compared in terms of construction waste generation


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