Solar backsheet (membrane) monitoring of external water vapor barrier performance - Database & Sql Blog Articles
Abstract: Water vapor transmission rate is an important performance index to characterize the solar water backsheet (membrane) barrier to external water vapor (moisture). It can effectively monitor the protection performance of solar panels on internal battery components and avoid solar cells. It is oxidized in the external environment. This paper uses the W3/330 water vapor transmission rate test system independently researched and developed by Jinan Languang Electromechanical Technology Co., Ltd. to test the water vapor transmission rate of the solar backsheet (film), and briefly describes the parameters, application scope and test of the equipment. The process provides a reference for the solar equipment manufacturing industry to verify the solar barrier properties of the solar backsheet material.
Keywords: water vapor transmission rate, moisture barrier, water vapor barrier, solar backsheet (film), solar cell, battery oxidation, water vapor transmission rate test system
1, meaning
The core component of solar energy equipment, solar panels, converts solar energy into electrical energy, enabling the development of renewable energy and clean energy. At present, most of the solar energy products are required to be used for more than 25 years. Therefore, the key components of the solar cell backplane (herein referred to as the solar backplane) must have a very high protective effect on the cells of the internal photovoltaic modules. The solar cell module is generally assembled by a "photovoltaic glass-EVA film-solar panel-EVA film-backboard" in an aluminum alloy frame. Currently, the commonly used solar backsheet materials mainly include a TPT backboard and a BBF backsheet. TPE backsheet, EVA backsheet, etc., wherein the TPT backsheet has high barrier properties, and it is a three-layer composite film of PVF (or PVDF) / PET / PVF (PVDF).
Since the solar cell module is placed outdoors for a long time, the backboard must have excellent properties of insulation, water resistance, and aging resistance, and should have high peel strength, tensile strength, and good heat shrinkage rate. The most important indicator is the water vapor transmission rate, which is the barrier index to external moisture. If the water vapor transmission rate of the back sheet (film) is large, that is, the barrier to water vapor (moisture) in the outside air is poor, moisture will penetrate into the back sheet to the inside of the solar back sheet, making the EVA possessed. The adhesive properties deteriorated, causing the backsheet to detach from the EVA, causing more moisture to contact the cell and oxidizing the cell. In this paper, the water vapor transmission rate test of the solar backsheet (film) was carried out using the W3/330 water vapor transmission rate test system independently developed by Jinan Languang Electromechanical Technology Co., Ltd., in order to verify the solar moisture barrier of the solar backsheet material. How is sex?
Figure 2 Solar backing material
2. Status
At present, the domestic test methods for water vapor transmission rate of soft plastic materials include weighing method (cup method), electrolysis method, humidity method and infrared method. The method standard that can be referred to is GB 1037-1988 "plastic film and sheet". Water vapor permeability test method cup method, GB/T 16928-1997 "packaging material test method moisture permeability", GB/T 21529-2008 "plastic film and sheet water vapor transmission rate measurement - electrolytic sensor method" , GB/T 30412-2013 "Plastics film and sheet water vapor transmission rate measurement humidity sensor method" (released, implemented on December 1, 2014).
In this paper, the water vapor transmission rate of fleshy pine packaging is tested by electrolysis. The standard is GB/T 21529-2008 "Determination of water vapor transmission rate of plastic film and flakes - Electrolytic sensor method".
3, test samples
A brand of solar cell backsheet (film).
4, test equipment
The test equipment used in this paper is the Labthink W3/330 water vapor transmission rate test system.
![Width="300" height="225" src="http://i.bosscdn.com/blog/20/17/10/2117950291317.jpg" /> Figure 3 W3/330 water vapor transmission Rate Test System</p></p><p align="center"></p><p><p >4.1 Test Principles</p></p><p><p>W3/330 Adoption Electrolytic sensor method test principle, nitrogen with stable relative humidity flows on one side of the film, dry nitrogen flows on the other side of the film; due to the existence of humidity gradient, water vapor will diffuse from the high wet side through the film to the low wet side; On the low-humidity side, the permeated water vapor is carried to the sensor by the flowing dry nitrogen gas. When entering the sensor, the same proportion of electric signal is generated, and the water vapor transmission rate of the sample is obtained by analyzing and calculating the electrical signal of the sensor. parameter. For the packaging container, dry nitrogen flows in the container, and the outside of the container is in a high-humidity state. </p></p><p><p >4.2 Device Parameters</p></p><p><p><!----[if !supportLists]---->l<! ----[endif]---->The routine test range of film samples is 0.001 ~ 40 g / (m < sup> 2 </sup> · 24h), can be extended to 0.01 ~ 1000 g / (m < Sup>2</sup>·24h), the resolution is 0.001 g/(m<sup>2</sup>·24h); the test range of container samples is 0.0001 ~ 0.2 g/(pkg·24h), The resolution is 0.00001 g/(pkg·24h). </p></p><p><p><!----[if !supportLists]---->l<!----[endif]---->The temperature range of the test is 15 ° C ~ 55 ° C, temperature control accuracy of ± 0.1 ° C; humidity range of 0% RH, 35% RH ~ 90% RH, 100% RH, humidity control accuracy of ± 1% RH. </p></p><p><p><!----[if !supportLists]---->l<!----[endif]---->The device is configured with three The test chamber and the three test chambers can be designed independently, and the test process does not interfere with each other, and the test results are displayed independently. </p></p><p><p ><!----[if !supportLists]---->l<!----[endif]---->The system can support up to 10 Station</p><p><p>Instrument</p><p>Connect in parallel to establish an efficient system for simultaneous testing of 30 samples. </p></p></p><p><p><!----[if !supportLists]---->l<!----[endif]---->provide Standard membranes are used for system calibration to ensure the accuracy and versatility of the test data. </p></p><p><p><!----[if !supportLists]---->l<!----[endif]----> can communicate with oxygen The rate test system is matched to form a hybrid test system, which is controlled by a computer to realize an efficient and convenient test method for simultaneous testing of water vapor and oxygen transmission rate. </p></p><p><p >4.3 Scope</p></p><p><p >(1) This device is suitable for film, sheet, paper, cardboard and Testing of water vapor transmission rate of packages such as composite materials and containers. The film includes various plastic film, plastic composite film, paper-plastic composite film, co-extruded film, aluminized film, aluminum foil, aluminum foil composite film, glass fiber aluminum foil paper composite film, etc.; sheet materials include various engineering plastics and rubber Sheet materials such as building materials, such as PP sheet, PVC sheet, PVDC sheet, etc.; paper, cardboard and composite materials including paper, cardboard, etc., such as cigarette coated aluminum paper, paper aluminum-plastic composite sheet; The device can also be used for testing the water vapor transmission rate of special packaging parts such as solar back panels, liquid crystal display films, medical blister packs, pharmaceutical plastic bottles, sterile protective film, automobile fuel tanks, and battery plastic casings. </p></p><p><p>The water vapor transmission rate of bottles, bags, cans, boxes and barrels made of plastic, rubber, paper, paper-plastic composite, glass, metal, etc. Testing, such as Coke bottles, peanut oil barrels, Tetra Pak packaging, vacuum packaging bags, metal packaging bags, metal three-piece cans, plastic cosmetic hose packaging, toothpaste hose packaging, jelly cups, etc. </p></p><p><p >(2) This device complies with national and international standards such as GB/T 21529, ISO 15106-3, DIN 53122-2, and YBB 00092003. </p></p><p><p>5, test procedure</p></p><p><p >(1) Using a special cutter to cut 108 mm × 108 from the surface of the specimen 3 samples of mm. </p></p><p><p >(2) Three samples were mounted on the three test chambers of the instrument and the test chamber was tightened. </p></p><p><p >(3) Set parameter information such as sample thickness, test temperature, and test humidity. </p></p><p><p >(4) Adjust the pressure of the nitrogen gas so that the humidity in the test chamber reaches the set value, and the nitrogen flow rate in the upper and lower chambers is reached by the nitrogen flow rate adjustment knob. Standard rating. </p></p><p><p >(5) Click the Start Test option and the test begins. The instrument automatically records the change in water molecule content on the low-humid side during the test and calculates the final test results. </p></p><p align="center"></p><p ><p align="center"></p><p align="center"><img alt=](http://i.bosscdn.com/blog/20/17/10/2117952361942.jpg)
Figure 4 sample clamping process
6, test results
The water vapor transmission rate test values ​​of the three samples were: 1.2405 g/(m 2 ·24h), 1.3114 g/(m 2 ·24h), and 1.3075 g/(m 2 ·24h), respectively.
7. Conclusion
W3/330 water vapor transmission rate test system is a professional testing equipment for film, sheet and container to the external water vapor barrier performance. It has the advantages of high detection precision and good repeatability of test results. The test of water vapor transmission rate can effectively monitor the life of solar cells. In addition to water vapor transmission rate testing equipment, Labthink can also provide you with the ability to test the tensile properties and peel strength of solar backsheets.
Tensile testing machine
For testing equipment such as physical and mechanical strength properties, you can check or consult the specific information about the equipment at The more you understand, the more you trust! Jinan Languang Electromechanical Technology Co., Ltd. is willing to enhance technical exchanges and cooperation with enterprises and institutions in the industry.
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