scholarly journals Thermal and Mechanical Properties of Green Insulation Composites Made from Cannabis and Bark Residues

2021 ◽  
Vol 5 (5) ◽  
pp. 132
Author(s):  
Konstantinos Ninikas ◽  
Andromachi Mitani ◽  
Dimitrios Koutsianitis ◽  
George Ntalos ◽  
Hamid R. Taghiyari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Cannabis Sativa ◽  
Raw Materials ◽  
Methyl Cellulose ◽  
Tree Bark ◽  
Low Density ◽  
Hemp Fibers ◽  
Pine Tree ◽  
Board Type

The objective of this paper was to investigate the technical feasibility of manufacturing low density insulation particleboards that were made from two renewable resources, namely hemp fibers (Cannabis sativa) and pine tree bark, which were bonded with a non-toxic methyl cellulose glue, as a binder. Four types of panels were made, which consisted of varying mixtures of tree bark and hemp fibers (tree bark to hemp fibers percentages of 90:10, 80:20, 70:30, and 60:40). An additional set of panels was made, consisting only of bark. The results showed that addition of hemp fibers to furnish improved mechanical properties of boards to reach an acceptable level. The thermal conductivity unfavorably increased as hemp content increased, though all values were still within the acceptable range. Based on cluster analysis, board type 70:30 (with 30% hemp content) produced the highest mechanical properties as well as the optimal thermal conductivity value. It is concluded that low density insulation boards can be successfully produced using these waste raw materials.

scholarly journals Utilization of SiC and Cu Particles to Enhance Thermal and Mechanical Properties of Al Matrix Composites

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2770 ◽  
Author(s):  
Dongxu Wu ◽  
Congliang Huang ◽  
Yukai Wang ◽  
Yi An ◽  
Chuwen Guo
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
High Thermal Conductivity ◽  
Low Density ◽  
Matrix Composites ◽  
Thermal And Mechanical Properties ◽  
Cu Content ◽  
Sic Particles ◽  
Al Matrix Composites ◽  
Al Matrix

In this work, SiC and Cu particles were utilized to enhance the thermal and mechanical properties of Al matrix composites. The ball-milling and cold-compact methods were applied to prepare Al matrix composites, and the uniform distribution of SiC and Cu particles in the composite confirms the validity of our preparation method. After characterizing the thermal conductivity and the compressibility of the prepared composites, results show that small particles have a higher potential to improve compressibility than large particles, which is attributed to the size effect of elastic modulus. The addition of SiC to the Al matrix will improve the compressibility behavior of Al matrix composites, and the compressibility can be enhanced by 100% when SiC content is increased from 0 to 30%. However, the addition of SiC particles has a negative effect on thermal conductivity because of the low thermal conductivity of SiC particles. The addition of Cu particles to Al-SiC MMCs could further slightly improve the compressibility behavior of Al-SiC/Cu MMCs, while the thermal conductivity could be enhanced by about 100% when the Cu content was increased from 0 to 30%. To meet the need for low density and high thermal conductivity in applications, it is more desirable to enhance the specific thermal conductivity by enlarging the preparation pressure and/or sintering temperature. This work is expected to supply some information for preparing Al matrix composites with low density but high thermal conductivity and high compressibility.

Synthesis, Characterization and Mechanical Properties of Silicon Carbide Nanowires

2010 ◽  
Author(s):  
Huan Zhang ◽  
Weiqiang Ding ◽  
Daryush Aidun
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Physical And Mechanical Properties ◽  
High Hardness ◽  
High Strength ◽  
Harsh Environments ◽  
Low Density ◽  
Low Thermal Expansion ◽  
Oxidation And Corrosion

Silicon carbide (SiC) material has many outstanding physical and mechanical properties such as high strength, high hardness, low density, high thermal conductivity, low thermal expansion coefficient, large band-gap, and excellent oxidation and corrosion resistances [1–3]. It is a leading material for components and devices operating at high temperature, high power and under harsh environments [4–5]. Micro-sized SiC particles and whiskers are commonly used as reinforcement materials for ceramics, metals and alloys in various structural and tribological applications [6–7].

scholarly journals Evaluation of Mechanical Properties and Volatile Organic Extractable to Investigate LLDPE and LDPE Polymers on Final Packaging for Semisolid Formulation

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 113 ◽  
Author(s):  
Arianna Cozzi ◽  
Benedetta Briasco ◽  
Enrico Salvarani ◽  
Barbara Mannucci ◽  
Filippo Fangarezzi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
Raw Materials ◽  
Plastic Material ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Two Samples ◽  
Volatile Organic ◽  
The Difference ◽  
And Performance

Plastic material is used for a wide variety of commercial packaging due to being inexpensive, lightweight, and due to its resistance. In pharmaceutics, container-content compatibility studies are required for product authorization. Many guidelines and publications are available; however, the information is often only related to the raw materials used to produce packaging. During the manufacturing process, substances can be added to improve the product characteristics and performance, resulting in a processed material that is considerably different from the unprocessed material. In this study, the mechanical properties of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) specimens fabricated according to standard ISO 527 and specimens fabricated with the same materials, but obtained from final packaging, were evaluated. Furthermore, we examined the interaction between a semisolid formulation and LLDPE and LDPE as a final packaging, by subjecting two samples to accelerated degradation testing. Then, mechanical properties and volatile organic extractable were evaluated. Simulated solar radiation did not induce changes in the packaging mechanical properties and no extracts were detectable. The thermal shock strongly influenced the mechanical behavior, and interactions between packaging contents were identified. The present work underlines the difference between analyzing the standard ISO specimens versus samples obtained from final packaging in order to evaluate the packaging under real use conditions. An evaluation on the final packaging, instead on standard specimens, can provide information about the plastic material after the manufacturing process and the interaction between packaging and content.

scholarly journals Thermal Behavior of Insulation Fiberboards Made from MDF and Paper Wastes

2021 ◽  
Vol 72 (3) ◽  
pp. 245-254
Author(s):  
Bita Moezzipour ◽  
Aida Moezzipour
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Thermal Analysis ◽  
Fire Resistance ◽  
Dimensional Stability ◽  
Raw Materials ◽  
Waste Paper ◽  
Recycled Fibers ◽  
Thermal Stability Of

Today, recycling is becoming increasingly important. In recycling process, the product performance should also be considered. In this study, manufacturing insulation fiberboard, as a practical wood product from recycled fibers, was investigated. For this purpose, two types of waste (MDF wastes and waste paper) were recycled to fibers and used for producing insulation fiberboards. The target fiberboard density was 0.3 g/cm3. The ratio of waste paper to MDF waste recycled fibers (WP/RF) was considered at two levels of 70/30 and 50/50. Polyvinyl acetate adhesive was used as a variable in the board manufacturing process. The mechanical properties, dimensional stability, thermal conductivity, and fire resistance of the boards were evaluated. Besides, the thermal stability of fiberboards was studied using thermal analysis including thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The results showed that the insulation fiberboards had admissible mechanical properties and dimensional stability. The manufactured boards displayed low thermal conductivity, which proved to be well competitive with other insulation materials. The fiberboards manufactured with PVAc adhesive and WP/RF ratio of 50/50 had higher fire resistance compared to other treatments. Additionally, results of thermal analysis showed that the use of PVAc adhesive and WP/RF ratio of 50/50 leads to improved thermal stability. Overall, the recycled fibers from MDF and paper wastes appear to be appropriate raw materials for manufacturing thermal insulation panels, and use of PVAc adhesive can significantly improve thermal and practical properties of insulation fiberboards.

scholarly journals Mechanically Strong, Low Thermal Conductivity and Improved Thermal Stability Polyvinyl Alcohol–Graphene–Nanocellulose Aerogel

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 170
Author(s):  
Xiuya Wang ◽  
Pengbo Xie ◽  
Ke Wan ◽  
Yuanyuan Miao ◽  
Zhenbo Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Polyvinyl Alcohol ◽  
Low Density ◽  
Composite Aerogel ◽  
Ternary Composite ◽  
Low Thermal Conductivity ◽  
Good Thermal Stability ◽  
Composite Aerogels

Porous aerogel materials have advantages of a low density, low thermal conductivity and high porosity, and they have broad application prospects in heat insulation and building energy conservation. However, aerogel materials usually exhibit poor mechanical properties. Single-component aerogels are less likely to possess a good thermal stability and mechanical properties. It is necessary to prepare multiple-composite aerogels by reinforcement to meet practical application needs. In this experiment, a simple preparation method for polyvinyl alcohol (PVA)–graphene (GA)–nanocellulose (CNF) ternary composite aerogels was proposed. This is also the first time to prepare ternary composite aerogels by mixing graphene, nanocellulose and polyvinyl alcohol. A GA–CNF hydrogel was prepared by a one-step hydrothermal method, and soaked in PVA solution for 48 h to obtain a PVA–GA–CNF hydrogel. PVA–GA–CNF aerogels were prepared by freeze drying. The ternary composite aerogel has advantages of excellent mechanical properties, a low thermal conductivity and an improved thermal stability, because strong hydrogen bonds form between the PVA, GA and CNF. The composite aerogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, Brunauer–Emmett–Teller analysis, dynamic thermal analysis, thermogravimetry and thermal constant analysis to characterize the properties of the ternary composite aerogels. The lightweight, low-density and porous PVA–GA–CNF composite aerogels withstood 628 times their mass. The thermal conductivity of the composite aerogels was 0.044 ± 0.005 W/mK at room temperature and 0.045 ± 0.005 W/mK at 70 °C. This solid, low thermal conductivity and good thermal stability PVA–GA–CNF ternary composite aerogel has potential application in thermal insulation.

Thermal Conductivity of Low-Density Wood Composite Mats

2019 ◽  
Vol 69 (4) ◽  
pp. 322-328
Author(s):  
Takashi Nakaya ◽  
Mariko Yamasaki ◽  
Satoshi Fukuta ◽  
Yuki Matsuda ◽  
Yasutoshi Sasaki
Keyword(s):  
Thermal Conductivity ◽  
Raw Materials ◽  
Japanese Cedar ◽  
Heat Transfer Process ◽  
Low Density ◽  
Wood Composite ◽  
Fiber Layer ◽  
Experimental Conditions ◽  
Density Region ◽  
Mat Density

Abstract In order to effectively use the waste produced during lumber sawing, the thermal conductivities of wood composite mats shaped by thermoforming and composed of wood shavings, kenaf fibers, and binders were examined by assuming a one-dimensional heat transfer process that could be described by the sum of its heat conduction and radiation components. To improve the heat-insulating properties of the mats, various types of auxiliary raw materials were examined. Mat density depended on the volumetric ratio of the air layer inside the mat to the fiber layer. In the low-density region, increasing the mat density decreased the magnitude of the radiation component and thus the thermal conductivity of the mat, whereas in the high-density region, increasing the mat density increased the value of the conduction component, which in turn enhanced the thermal conductivity of the mat. The minimum value of the thermal conductivity obtained under all experimental conditions is 0.062 W/m·K. Thus, it is difficult to decrease the thermal conductivity of the mat below 0.060 W/m·K by varying its density and mixing ratio. The utilized model predicted that mat thermal conductivity would be less than 0.060 W/m·K if the fibers with a density similar to that of Japanese cedar wood (0.40 g/cm3) were used.

Physico-mechanical characterization of non-stabilized Compressed Earth Blocks

2020 ◽  
Author(s):  
Marios Kyriakides ◽  
Rafail Panagiotou ◽  
Rogiros Illampas ◽  
Michalis Tapakoudis ◽  
Ioannis Ioannou
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Raw Materials ◽  
Capillary Absorption ◽  
Ongoing Research ◽  
Development Fund ◽  
Granular Composition ◽  
Compressed Earth Blocks ◽  
Earth Blocks

<p>Recent challenges faced by humanity in relation to the ongoing climatic changes around the globe, have led many practitioners and researchers search for new environmentally friendly materials to use in construction, such as earth-based materials. A specific form of an earth-based building material that nowadays receives particular attention is Compressed Earth Blocks (CEBs). CEBs comprise of soil mixed at low moisture content and are formed under high pressure in compression, without firing. The end-products can be non-stabilized, i.e., without any cement or lime added, or stabilized, whereby a small quantity of stabilizer (<12% by weight) is added, mainly for enhancing their mechanical and durability properties. CEBs, particularly the non-stabilized ones, are considered to be less expensive and environmentally friendlier, compared to the traditional fired clay bricks, due to their lower production cost and excellent recyclability potential, which significantly reduces the end-product’s environmental impact.</p><p>In Cyprus, CEBs were not used in the past, as the prevailing earth building technique on the island was adobe masonry. Recently, however, there appears to be an interest in the use of this material for contemporary construction. The work hereby presented is part of an ongoing research project that focuses on the design, production and characterization of a sustainable and eco-friendly prototype CEB masonry system that will be fabricated using raw materials originating from Cyprus. The project is funded by the European Regional Development Fund and the Republic of Cyprus, through the Cyprus Research and Innovation Foundation (Project ENTERPRISES/0618/0007).</p><p>In the framework of the aforementioned project, various types of locally sourced soils, with different mineralogical/granular composition and plasticity characteristics have been selected and used for the production of non-stabilized CEBs. A series of tests, including particle-size analysis, Atterberg limits determination, shrinkage and compaction measurements, and X-ray diffraction analyses have been carried out to determine the characteristics of the raw materials selected. In addition, compression and 3-point bending tests, capillary absorption measurements and thermal conductivity analyses have been conducted to assess the physico-mechanical properties of the CEBs produced.</p><p>XRD analyses have shown that the soils investigated are mainly composed of carbonates and silicates at different ratios. Preliminary capillary absorption tests have demonstrated that the use of a non-reactive liquid, such as acetone, is better over water in determining the sorptivity of non-stabilized CEBs. In addition, the thermal conductivity of all specimens ranged between 0.60-0.85 W/mK. Finally, the results suggest that, despite the different granular composition of the soils used, all soils demonstrated adequate mechanical properties in terms of compressive (over 5 MPa) and flexural (over 0.5 MPa) strength.  </p>

Development of Carbon Nanotube - Reinforced Silk and Cannabis Fibers by an Electrophoretic Deposition Method

2011 ◽  
Vol 695 ◽  
pp. 377-380
Author(s):  
Somjate Veingnon ◽  
Yaowamarn Chuminjak ◽  
Tewasin Kumpika ◽  
Pisith Singjai
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrophoretic Deposition ◽  
Cannabis Sativa ◽  
Natural Fibers ◽  
Break Point ◽  
Deposition Method ◽  
Hemp Fibers ◽  
Carboxylic Acid Groups ◽  
Mixed Acids

Carbon nanotubes (CNTs) were deposited by electrophoretic deposition (EPD) onBombyx mori(silk) andCannabis sativa L. var.sativa (hemp) fibers to improve their mechanical properties. The CNTs were functionalized in mixed acids in order to introduce carboxylic acid groups on their surfaces. The tensile strength and strain at break point of both the modified fibers were approximately two times higher than those of the virgin natural fibers. The addition of small amounts of Mg(NO3)2.6H2O, (CH3COO)2Ni.4H2O significantly improved the deposition of the functionalized CNTs on the hemp fibers.

scholarly journals Acoustic absorption and thermal insulation of wood panels: Influence of porosity

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3746-3757
Author(s):  
Marilia da Silva Bertolini ◽  
César Augusto Galvão de Morais ◽  
André Luis Christoforo ◽  
Stelamaris Rolla Bertoli ◽  
Wilson Nunes dos Santos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Sound Absorption ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Pressing Pressure ◽  
Reverberation Chamber ◽  
Polyurethane Resin ◽  
Highly Porous

The development of materials that offer environmental comfort inside buildings, through adequate thermal and acoustic behavior, has been as relevant as the search for raw materials of renewable origin. In this context, this study produced and characterized panels made with Pinus sp. waste materials, which were treated with a copper chrome boric oxide preservative and a castor-oil based polyurethane resin. The physical and mechanical properties of the panels were evaluated according to the ABNT NBR 14810 standard (2013). The panel porosity was investigated by scanning electron microscopy (SEM) and mercury intrusion porosimetry techniques. The sound absorption was analyzed by a reverberation chamber and thermal conductivity by the modified fractionated column method. Samples with a higher pressing pressure (4 MPa) during the manufacturing presented lower thickness swelling and higher mechanical properties in static bending. Panels made with a lower press pressure (2.5 MPa) resulted in a higher porosity volume (55.7%). The more highly porous panels were more acoustically efficient, with a sound absorption coefficient close to 0.8 at 3.2 kHz, and they had a better thermal conductivity performance.The potential of these panels for application where sound absorption and thermal insulation are prioritized is thus observed.

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