In the Course of our work , sometimes we might need to identify unknown samples. One of the best way thus far in fulfilling this was the use of DSC, Differential scanning calorimetry.
Differential scanning calorimetry or DSC is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and reference are maintained at nearly the same temperature throughout the experiment. Generally, the temperature program for a DSC analysis is designed such that the sample holder temperature increases linearly as a function of time. The reference sample should have a well-defined heat capacity over the range of temperatures to be scanned.
Wikipedia provide a very in depth explaination regarding this subject: the link can be sort at the following:
DSC
Wednesday, May 19, 2010
Tuesday, May 11, 2010
Quality Control for Glass
There is a series of test that undergoes to ensure solar glass can perfomed to spec
-Light transmittance Test
-impact Test
-Boil Test
-Loading Test
-Bow Measurement
-Dimension Measurement
-Diagonal Line measurement
-Arch Measurement
-Fragment measurement
-surface checking
-resistance measurement
Quality Control Specification and Picture
-Light transmittance Test
-impact Test
-Boil Test
-Loading Test
-Bow Measurement
-Dimension Measurement
-Diagonal Line measurement
-Arch Measurement
-Fragment measurement
-surface checking
-resistance measurement
Quality Control Specification and Picture
Normal CLear Float Glass
Common Clear Float Tempered Glass
What is Clear Float Tempered/Toughened Glass?
Clear float glass, it is molten glass floats on the tin and
spreads out thus seeking a controlled level. Control heating will then allows the glass to flow and form a float ribbon of uniform thickness while on the tin bath. Glass is then slowlycooled and fed off from the molten tin into the annealing lehr for further cooling.
Clear float tempered/toughened glass is float glass that has been processed through a tempering oven to
increase its strength to resist impact, mechanical loads and thermal
stress breakage.
Glass is heat-treated by heating annealed glass to a temperature of approximately 1,150°F (621°C), then rapidly cooling it. The glass is cooled by a carefully controlled airflow (also known as quenching), which uniformly cools all glass surfaces simultaneously.
It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Characteristics
It is smooth without any pattern on glass surface.
The energy transmittance about 88%
It is of less cost compare to low iron glass
It is a little green seen from edges.
Where to use it?
· Substrate of semiconductor of thin film photovoltaic technology, including amorphous silicon (aSi), cadmium telluride (CdTe) and copper indium diselenide (CIS).
· Thermal Collector.
What is Clear Float Tempered/Toughened Glass?
Clear float glass, it is molten glass floats on the tin and
spreads out thus seeking a controlled level. Control heating will then allows the glass to flow and form a float ribbon of uniform thickness while on the tin bath. Glass is then slowlycooled and fed off from the molten tin into the annealing lehr for further cooling.
Clear float tempered/toughened glass is float glass that has been processed through a tempering oven to
increase its strength to resist impact, mechanical loads and thermal
stress breakage.
Glass is heat-treated by heating annealed glass to a temperature of approximately 1,150°F (621°C), then rapidly cooling it. The glass is cooled by a carefully controlled airflow (also known as quenching), which uniformly cools all glass surfaces simultaneously.
It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Characteristics
It is smooth without any pattern on glass surface.
The energy transmittance about 88%
It is of less cost compare to low iron glass
It is a little green seen from edges.
Where to use it?
· Substrate of semiconductor of thin film photovoltaic technology, including amorphous silicon (aSi), cadmium telluride (CdTe) and copper indium diselenide (CIS).
· Thermal Collector.
Low Iron Float Glass/ Ultra Clear glass
What is Low Iron Float Tempered Glass?
Low iron float glass also named Ultra-clear glass. It is made by matured technical operation norm. It looks just like colorless crystal with higher transmittance.
Compare to common float glass, it is with outstanding characteristics of the high solar lights transmittance, the low reflectance, the low iron, the high mechanical strength and the high flatness, it is the ideal encapsulation material for thin solar modules and thermal collectors.
Low iron float tempered glass is low iron float glass that
has been processed through a tempering oven to increase its strength to resist impact, mechanical loads and thermal stress breakage. It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Characteristics
It is of higher energy transmittance about 91%
It is expensive compare to clear float glass
It is highly smooth without patterned which more suitable for thin film solar modules and thermal collectors.
Where to use it?
· Front cover glass of of thin film photovoltaic technology, including amorphous silicon (aSi), cadmium telluride (CdTe) and copper indium diselenide (CIS).
· Front cover glass of thermal collectors.
Low iron float glass also named Ultra-clear glass. It is made by matured technical operation norm. It looks just like colorless crystal with higher transmittance.
Compare to common float glass, it is with outstanding characteristics of the high solar lights transmittance, the low reflectance, the low iron, the high mechanical strength and the high flatness, it is the ideal encapsulation material for thin solar modules and thermal collectors.
Low iron float tempered glass is low iron float glass that
has been processed through a tempering oven to increase its strength to resist impact, mechanical loads and thermal stress breakage. It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Characteristics
It is of higher energy transmittance about 91%
It is expensive compare to clear float glass
It is highly smooth without patterned which more suitable for thin film solar modules and thermal collectors.
Where to use it?
· Front cover glass of of thin film photovoltaic technology, including amorphous silicon (aSi), cadmium telluride (CdTe) and copper indium diselenide (CIS).
· Front cover glass of thermal collectors.
Low Iron Pattered Glass
Low Iron Patterned Tempered Glass
What is Low Iron Patterned Tempered Glass?
Low iron patterned glass, also called low iron figured glass or low iron rolled glass or low iron textured glass, is made by a continuous roll-impressed process. Low iron patterned glass with excellent performance on high solar transmittance, low absorbance, low reflectance and low iron content, is the ideal encapsulationmaterial for solar thermal and photovoltaic modules.Low iron patterned tempered glass is low ironpatternedglass that has been processed through a
tempering ovento increase its strength to resist impact, mechanical loads and thermal stress breakage. Glass is heat-treated by heating annealed glass to a temperature of approximately 1,150°F (621°C), then rapidly cooling it. The glass is cooled by a carefully controlled airflow (also known as quenching), which uniformly cools all glass surfaces simultaneously.
It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Specifications and Properties of Raw Glass:
1、Glass Thickness：3.2m &4mm；
2、Tolerance of thickness：±0.15mm
3、Max. Size：1650mm×2440mm
4、Light transmittance（3.2mm）：≥91.6%
5、Content Iron：≤150ppmFe2O3
6、Specific Heat at 32° -212°F (0° -100°C)：0.2
7、Density：2.5g/cc
8、(Young's) Modulus of Elasticity ：73GPa
9、Tensile Strength ：42 MPa
10、Hemispherical Emissivity at 0° -150° (-18° -66°C)：0.84
11、Expansion Coefficient ：9.03x10-6/℃
12、Softening Point：720 ℃
13、Annealing Point：550 ℃
14、Strain Point：500 ℃
Characteristics
It is of higher energy transmittance about 91.5%
It is expensive compare to clear float glass
It has two types of surface patterns, prismatic/matt-finished (SM) and matt-finished/matt-finished (MM).
Series of low iron patterned glass:
· Raw glass without tempered
· Tempered with designed sizes
Where to use it?
· Front cover glass of Crystalline silicon (cSi) including monocrystalline solar panels, polycrystalline solar panels.
What is Low Iron Patterned Tempered Glass?
Low iron patterned glass, also called low iron figured glass or low iron rolled glass or low iron textured glass, is made by a continuous roll-impressed process. Low iron patterned glass with excellent performance on high solar transmittance, low absorbance, low reflectance and low iron content, is the ideal encapsulationmaterial for solar thermal and photovoltaic modules.Low iron patterned tempered glass is low ironpatternedglass that has been processed through a
tempering ovento increase its strength to resist impact, mechanical loads and thermal stress breakage. Glass is heat-treated by heating annealed glass to a temperature of approximately 1,150°F (621°C), then rapidly cooling it. The glass is cooled by a carefully controlled airflow (also known as quenching), which uniformly cools all glass surfaces simultaneously.
It is approximately four times stronger than annealed glass of the same thickness and configuration. When it is broken, tempered glass fractures into small fragments that reduce the probability of serious injury as compared to annealed glass.
Specifications and Properties of Raw Glass:
1、Glass Thickness：3.2m &4mm；
2、Tolerance of thickness：±0.15mm
3、Max. Size：1650mm×2440mm
4、Light transmittance（3.2mm）：≥91.6%
5、Content Iron：≤150ppmFe2O3
6、Specific Heat at 32° -212°F (0° -100°C)：0.2
7、Density：2.5g/cc
8、(Young's) Modulus of Elasticity ：73GPa
9、Tensile Strength ：42 MPa
10、Hemispherical Emissivity at 0° -150° (-18° -66°C)：0.84
11、Expansion Coefficient ：9.03x10-6/℃
12、Softening Point：720 ℃
13、Annealing Point：550 ℃
14、Strain Point：500 ℃
Characteristics
It is of higher energy transmittance about 91.5%
It is expensive compare to clear float glass
It has two types of surface patterns, prismatic/matt-finished (SM) and matt-finished/matt-finished (MM).
Series of low iron patterned glass:
· Raw glass without tempered
· Tempered with designed sizes
Where to use it?
· Front cover glass of Crystalline silicon (cSi) including monocrystalline solar panels, polycrystalline solar panels.
Wednesday, April 14, 2010
Materials needed for Testing
In RED , material needed , always revolved around aluminium, glass, stainless steel.
Thus i will cater a post space for this matter.
Aluminium:
Al 6061
Al 6061 Composition, Properties, Temper and Applications of 6061 Aluminium
Al 2024
Thus i will cater a post space for this matter.
Aluminium:
Al 6061
Al 6061 Composition, Properties, Temper and Applications of 6061 Aluminium
Al 2024
Tuesday, April 13, 2010
Photovoltaic Encapsulant Optical Property Study
All Photovoltaic Study of glass panel should be discuss here:
Photovoltaic Encapsulant Optical Property Study
This paper will present a technical comparison of several incumbent and candidate encapsulants that can be used for thin-film photovoltaic module manufacturing. We will focus on moisture ingress behavior and mechanical properties of several polymers. Most thin-film technologies are moisture sensitive; meaning, they can experience decreases in power output as a result of moisture ingress. One of the most important tests for this is a "damp heat" test defined by IEC 61646, where a module is placed for a period of time at 85oC and 85% relative humidity. Moisture ingress data measured in from the sides of glass-glass laminates after 1000 to 5000 hours of damp heat testing will be discussed. Resulting data for PVB, EVA and several ionomer-based encapsulants (commercial and experimental ionomers) will be compared.
Besides its role in protecting a cell from moisture and other environmental factors, an encapsulant also contributes to mechanical strength in a module. Finite Element Modeling (FEM) can be used to calculate the strength behavior of modules made with alternative encapsulants, under mechanical wind load test conditions (2.4 kPa uniform pressure for 1 hour). FEM modeling using a theoretical module will be discussed, where the variables are:
type of encapsulant (we will discuss all encapsulants mentioned);
support system (2-sided versus 4-sided);
glass thickness; and
encapsulant thickness.
We will compare some of these calculations with real mechanical load tests.
Comparison of Moisture Behavior and Mechanical Strength of Several Encapsulants
Encapsulant materials can provide protection and electrical isolation of the solar components in photovoltaic (PV) modules from the environment. However, some photovoltaic devices are sensitive to low levels of moisture and the ingress of water into a module can decrease its performance significantly during the lifetime of a module. In glass/glass PV modules, the moisture penetrates through the encapsulant to the module’s metal components and degradation can occur. In this study, we have developed and validated methods to determine moisture ingress in situ in a laminate. Results indicate that water permeability and equilibrium moisture level (which are temperature dependent) can both affect the corrosion of the metal. We have measured the moisture ingress through a developmental encapsulant material from the glass edge towards the center by an in-situ Fourier transform infrared (FTIR) spectroscopy technique after damp-heat exposure. The FTIR measurements were performed on glass / encapsulant / glass laminates that were weathered at various times at elevated temperatures and humidity. The moisture level in the encapsulant can be determined by integration of the IR band between 1880 and 1990 nm. This peak surface was compared to a calibration curve, which was obtained using laminates with known encapsulant moisture levels (determined by Karl- Fischer titration). The moisture migration through an encapsulant material from the edge was also measured using an ASTM D7191 moisture analysis method [1]. The measurements were made on Al foil/encapsulant/Al foil laminates that were exposed to 85°C and 85%RH (damp heat). The experimental data from both methods were well-correlated using a Fickian diffusion model.
DETERMINATION OF MOISTURE INGRESS THROUGH VARIOUS ENCAPSULANTS IN GLASS/GLASS LAMINATES
Photovoltaic Encapsulant Optical Property Study
This paper will present a technical comparison of several incumbent and candidate encapsulants that can be used for thin-film photovoltaic module manufacturing. We will focus on moisture ingress behavior and mechanical properties of several polymers. Most thin-film technologies are moisture sensitive; meaning, they can experience decreases in power output as a result of moisture ingress. One of the most important tests for this is a "damp heat" test defined by IEC 61646, where a module is placed for a period of time at 85oC and 85% relative humidity. Moisture ingress data measured in from the sides of glass-glass laminates after 1000 to 5000 hours of damp heat testing will be discussed. Resulting data for PVB, EVA and several ionomer-based encapsulants (commercial and experimental ionomers) will be compared.
Besides its role in protecting a cell from moisture and other environmental factors, an encapsulant also contributes to mechanical strength in a module. Finite Element Modeling (FEM) can be used to calculate the strength behavior of modules made with alternative encapsulants, under mechanical wind load test conditions (2.4 kPa uniform pressure for 1 hour). FEM modeling using a theoretical module will be discussed, where the variables are:
type of encapsulant (we will discuss all encapsulants mentioned);
support system (2-sided versus 4-sided);
glass thickness; and
encapsulant thickness.
We will compare some of these calculations with real mechanical load tests.
Comparison of Moisture Behavior and Mechanical Strength of Several Encapsulants
Encapsulant materials can provide protection and electrical isolation of the solar components in photovoltaic (PV) modules from the environment. However, some photovoltaic devices are sensitive to low levels of moisture and the ingress of water into a module can decrease its performance significantly during the lifetime of a module. In glass/glass PV modules, the moisture penetrates through the encapsulant to the module’s metal components and degradation can occur. In this study, we have developed and validated methods to determine moisture ingress in situ in a laminate. Results indicate that water permeability and equilibrium moisture level (which are temperature dependent) can both affect the corrosion of the metal. We have measured the moisture ingress through a developmental encapsulant material from the glass edge towards the center by an in-situ Fourier transform infrared (FTIR) spectroscopy technique after damp-heat exposure. The FTIR measurements were performed on glass / encapsulant / glass laminates that were weathered at various times at elevated temperatures and humidity. The moisture level in the encapsulant can be determined by integration of the IR band between 1880 and 1990 nm. This peak surface was compared to a calibration curve, which was obtained using laminates with known encapsulant moisture levels (determined by Karl- Fischer titration). The moisture migration through an encapsulant material from the edge was also measured using an ASTM D7191 moisture analysis method [1]. The measurements were made on Al foil/encapsulant/Al foil laminates that were exposed to 85°C and 85%RH (damp heat). The experimental data from both methods were well-correlated using a Fickian diffusion model.
DETERMINATION OF MOISTURE INGRESS THROUGH VARIOUS ENCAPSULANTS IN GLASS/GLASS LAMINATES
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