DENSE GLASS FOAM PRODUCED IN MICROWAVE FIELD

2018 ◽  
Vol 24 (1) ◽  
pp. 30-35
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
BOGDAN VALENTIN PAUNESCU
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Building Materials ◽  
Microwave Field ◽  
Microwave Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Mechanical Feature ◽  
Glass Foam ◽  
Fluxing Agent

Experimental results obtained in the process of manufacturing dense glass foam using the microwave energy are presented in the work. The glass foam is produced from bottle glass waste, calcium carbonate as foaming agent and borax as fluxing agent. The high compressive strength (2.5 - 6.2 MPa) is the main mechanical feature of this product, which together with other physical and morphological features (apparent density 0.60 – 0.90 g/cm3, porosity 59.1 – 72.7%, thermal conductivity 0.081 – 0.105 W m K, water absorption 0.5 – 1.0%, pore size 0.5 – 3 mm), are appropriate for using as a substitute for similar building materials existing on the market.

scholarly journals DENSE GLASS FOAM PRODUCED IN MICROWAVE FIELD

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
BOGDAN VALENTIN PAUNESCU
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Building Materials ◽  
Microwave Field ◽  
Microwave Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Mechanical Feature ◽  
Glass Foam ◽  
Fluxing Agent

<p>Experimental results obtained in the process of manufacturing dense glass foam using the microwave energy are presented in the work. The glass foam is produced from bottle glass waste, calcium carbonate as foaming agent and borax as fluxing agent. The high compressive strength (2.5 - 6.2 MPa) is the main mechanical feature of this product, which together with other physical and morphological features (apparent density 0.60 – 0.90 g/cm<sup>3</sup>, porosity 59.1 – 72.7%, thermal conductivity 0.081 – 0.105 W m K, water absorption 0.5 – 1.0%, pore size 0.5 – 3 mm), are appropriate for using as a substitute for similar building materials existing on the market.</p>

USE OF NATURAL DOLOMITE AS A CHEAP FOAMING AGENT FOR PRODUCING GLASS FOAMS FROM GLASS WASTE IN THE MICROWAVE FIELD

2020 ◽  
Vol 26 (1) ◽  
pp. 57-64
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Thermal Conductivity ◽  
Microwave Field ◽  
Specific Energy Consumption ◽  
Morphological Characteristics ◽  
Microwave Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Insulating Material ◽  
The World ◽  
Glass Foam

The paper presents experimental results obtained in the process of making glass foam from glass waste using a cheap foaming agent (natural dolomite). The originality of the work is the application of the microwave energy, unlike the conventional techniques commonly used in the world. The main advantage highlighted by the experiments is the very low specific energy consumption (below 1.5 kWh/kg), due to the peculiarities of the microwave heating technique. The foamed product has physical, mechanical and morphological characteristics (density between 0.30-0.32 g/cm3, thermal conductivity between 0.064-0.067 W/m·K, compressive strength in the range 2.2-2.6 MPa), which are similar to those of foams made by conventional methods and are suitable for its use as insulating material in construction.

scholarly journals USE OF NATURAL DOLOMITE AS A CHEAP FOAMING AGENT FOR PRODUCING GLASS FOAMS FROM GLASS WASTE IN THE MICROWAVE FIELD

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE
Keyword(s):  
Thermal Conductivity ◽  
Microwave Field ◽  
Specific Energy Consumption ◽  
Morphological Characteristics ◽  
Microwave Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Insulating Material ◽  
The World ◽  
Glass Foam

<p>The paper presents experimental results obtained in the process of making glass foam from glass waste using a cheap foaming agent (natural dolomite). The originality of the work is the application of the microwave energy, unlike the conventional techniques commonly used in the world. The main advantage highlighted by the experiments is the very low specific energy consumption (below 1.5 kWh/kg), due to the peculiarities of the microwave heating technique. The foamed product has physical, mechanical and morphological characteristics (density between 0.30-0.32 g/cm<sup>3</sup>, thermal conductivity between 0.064-0.067 W/m·K, compressive strength in the range 2.2-2.6 MPa), which are similar to those of foams made by conventional methods and are suitable for its use as insulating material in construction.</p>

scholarly journals NONCONVENTIONAL TECHNIQUE FOR PRODUCING HIGH MECHANICAL STRENGTH GLASS FOAM FROM GLASS WASTE

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Energy Source ◽  
Mechanical Strength ◽  
Electromagnetic Waves ◽  
Building Materials ◽  
Glass Waste ◽  
High Mechanical Strength ◽  
Foaming Agent ◽  
Heating Efficiency ◽  
Glass Foam

In the work experimental results on the manufacture of glass foam with high mechanical strength from glass waste are presented. By replacing the usual conventional energy source with a nonconventional energy (electromagnetic waves) the heating efficiency allows a fast and economical manufacturing process. Calcium carbonate as a foaming agent and an addition of sodium silicate (aqueous solution) as a binder were used. By their physico-mechanical and morphological features (0.40-0.66 g/ cm<sup>3 </sup>the apparent density, 0.054-0113 W/ m·K the thermal conductivity, 2.2-6.3 MPa the compressive strength, below 1.2 % the water absorption and under 2 mm the pore size), the foams are appropriate for their use as replacer of existing similar building materials on the market.

NONCONVENTIONAL TECHNIQUE FOR PRODUCING HIGH MECHANICAL STRENGTH GLASS FOAM FROM GLASS WASTE

2019 ◽  
Vol 25 (2) ◽  
pp. 48-55
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Energy Source ◽  
Mechanical Strength ◽  
Electromagnetic Waves ◽  
Building Materials ◽  
Glass Waste ◽  
High Mechanical Strength ◽  
Foaming Agent ◽  
Heating Efficiency ◽  
Glass Foam

In the work experimental results on the manufacture of glass foam with high mechanical strength from glass waste are presented. By replacing the usual conventional energy source with a nonconventional energy (electromagnetic waves) the heating efficiency allows a fast and economical manufacturing process. Calcium carbonate as a foaming agent and an addition of sodium silicate (aqueous solution) as a binder were used. By their physico-mechanical and morphological features (0.40-0.66 g/ cm3 the apparent density, 0.054-0113 W/ m·K the thermal conductivity, 2.2-6.3 MPa the compressive strength, below 1.2 % the water absorption and under 2 mm the pore size), the foams are appropriate for their use as replacer of existing similar building materials on the market.

USE OF THE MICROWAVE ENERGY FOR ALUMINUM WASTE FOAMING

2019 ◽  
Vol 25 (4) ◽  
pp. 43-49
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Porous Structure ◽  
Powder Mixture ◽  
Aluminum Foam ◽  
Fine Powder ◽  
Microwave Energy ◽  
Raw Material ◽  
Foaming Agent ◽  
Foaming Process

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.

scholarly journals Adequate Correlation between the Physical and Mechanical Properties of Glass Foam

2021 ◽  
Vol 1 (4) ◽  
pp. 14-26
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Marius Florin Dragoescu ◽  
Felicia Cosmulescu
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Thermal Insulation ◽  
Coal Fly Ash ◽  
Physical And Mechanical Properties ◽  
Ceramic Foam ◽  
Glass Waste ◽  
Glass Foam

The paper presents experimental results obtained in the manufacturing process of a glass foam by adequate correlation between its physical and thermal properties (density, porosity, thermal conductivity) and mechanical (compressive strength) by a slight controlled overheating of the foamed material. Using a powder mixture of glass waste (87-91.5 %), coal fly ash (3-9 %) and silicon carbide (4-5.5 %) microwave heated at 935-975 ºC by this unconventional technique, constituting the originality of the work, was obtained a glass-ceramic foam with moderate compressive strength (1.8-2.6 MPa) and very low thermal conductivity (0.058-0.070 W/m·K). The material overheating generated a homogeneous porous structure characterized by closed cells with relatively large dimensions (without the tendency to join neighboring cells) making it difficult to transfer heat across the material. The foamed product is suitable for the manufacture of thermal insulation blocks for the inner or outer walls of the building without excessive mechanical stress, being an advantageous alternative by comparison with known types of polymeric or fiberglass thermal insulation materials.

scholarly journals New Manufacturing Method of Glass Foam by Cold Expansion of Glass Waste

2021 ◽  
Vol 2 (3) ◽  
pp. 1-9
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Bogdan Valentin Paunescu
Keyword(s):  
Thermal Conductivity ◽  
Aqueous Solution ◽  
Compressive Strength ◽  
High Temperature ◽  
Insulation Material ◽  
Glass Waste ◽  
Foaming Agents ◽  
Manufacturing Method ◽  
Aluminium Powder ◽  
Glass Foam

Abstract                                                         An innovation cold manufacturing method of glass foams is presented in the paper. Traditional foaming agents used in conventional expansion processes of glass waste at high temperature were substituted with aluminium powder in aqueous solution of calcium hydroxide, which releases hydrogen forming gas bubbles in the viscous sludge and then, by solidification, a porous structure typical for the glass foam. The manufactured foam is adequate for using as a thermal insulation material for inner wall of buildings, having the apparent density of 0.31 g·cm-3, the thermal conductivity of 0.070 W/m·K and the compressive strength of 1.32 MPa. The process originality is the use of recycled aluminum waste, melted by an own microwave heating technique and sprayed with nitrogen jets. The process effectiveness is remarkable in economical and energy terms.

scholarly journals Adequate Correlation between the Physical and Mechanical Properties of Glass Foam

2021 ◽  
Vol 2 (4) ◽  
pp. 14-26
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Marius Florin Dragoescu ◽  
Felicia Cosmulescu
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Thermal Insulation ◽  
Coal Fly Ash ◽  
Physical And Mechanical Properties ◽  
Ceramic Foam ◽  
Glass Waste ◽  
Glass Foam

The paper presents experimental results obtained in the manufacturing process of a glass foam by adequate correlation between its physical and thermal properties (density, porosity, thermal conductivity) and mechanical (compressive strength) by a slight controlled overheating of the foamed material. Using a powder mixture of glass waste (87-91.5 %), coal fly ash (3-9 %) and silicon carbide (4-5.5 %) microwave heated at 935-975 ºC by this unconventional technique, constituting the originality of the work, was obtained a glass-ceramic foam with moderate compressive strength (1.8-2.6 MPa) and very low thermal conductivity (0.058-0.070 W/m·K). The material overheating generated a homogeneous porous structure characterized by closed cells with relatively large dimensions (without the tendency to join neighboring cells) making it difficult to transfer heat across the material. The foamed product is suitable for the manufacture of thermal insulation blocks for the inner or outer walls of the building without excessive mechanical stress, being an advantageous alternative by comparison with known types of polymeric or fiberglass thermal insulation materials.

scholarly journals Ultra-light Colorless and Green Glass Foam Produced by Microwave Radiation

2021 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Felicia Cosmulescu ◽  
Marius Florin Dragoescu ◽  
Bogdan Valentin Paunescu
Keyword(s):  
High Performance ◽  
Microwave Field ◽  
Specific Energy Consumption ◽  
High Energy ◽  
Glass Waste ◽  
Foaming Agent ◽  
Very High Energy ◽  
Green Glass ◽  
Glass Foam ◽  
Very High

Abstract                                                         According to the research objective that was the basis of the paper, an ultra-light glass foam with an apparent density of 0.14 g/cm3 was experimentally made from 98.9% post-consumer glass bottle and 1% CaCO3 as a foaming agent by sintering/foaming at 823 ºC in microwave field with a very low specific energy consumption (0.70 kWh/kg). A very advanced mechanical processing of glass waste (below 32 μm) and a very fine granulation (below 6.3 μm) of CaCO3 were the solutions adopted to obtain this high-performance product. The originality of the work is the use of the unconventional technique of predominantly direct microwave heating with a very high energy efficiency, applied by authors in recent years and presented in several previous papers.

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