1、What is the purpose of the light aging test?
The economic loss caused by aging is hundreds of millions of dollars every year. Aging often causes changes in the physical properties of textiles, coatings, plastics and other organic materials, mainly in the form of discoloration, loss of light, loss of strength, cracking, peeling, chalking and oxidation. We know that sunlight, especially short wavelength UV light, high temperature, rain, dew and moisture in the form of high humidity are the main factors causing these damages.
The purposes of using UV Accelerated Weathering Tester to test various types of materials are as follows.
(1) To reduce the risk of return
(2) To comply with relevant quality and technical standards.
(3) To avoid losses caused by aging.
(4) To improve the reputation of the product.
(5) To improve the competitiveness of the product.
(6) To enter the high-end market.
(7) Save resources.
(8) Life cycle prognosis.
2、What is the significance of accelerated aging in laboratory? What are the advantages over natural exposure to sunlight?
As the natural aging test takes several years to decide the aging result, the time cost is too high for general enterprises, especially in this era of fierce competition, the product development cycle is very short, if the testing cycle of a new product takes several years, then the product is not competitive at all to speak of. At the same time, because the climate conditions vary a lot, the same material under test may get very different aging results, and the repeatability and reproducibility of the experimental results are not very good. Therefore, people tend to use UV Accelerated Weathering Tester for artificial accelerated weathering, which not only can shorten the test cycle, but also has good repeatability and can be used for quality control, material stability testing and rapid comparative screening test of materials. In addition, this method has a wide range of applications, because it is only used indoors, it can be free from natural conditions and only consider the influence of human factors, easy to use and high controllability.
3、How long is the laboratory UV Accelerated Weathering Tester equivalent to a year in the natural environment?
This question is one of the most frequently asked questions, but also one of the most difficult to answer, even in the aging of knowledgeable and experienced researchers will also feel difficult, there is no standard or paper has clearly pointed out that the laboratory UV Accelerated Weathering Tester how long equivalent to a year in the natural environment or give a clear formula. The main reason is that there are too many factors that change in natural conditions and cause product aging such as light intensity, light duration, temperature, humidity, rainfall and pollutants, etc. The lab cannot simulate them all. Therefore, most of the current standards do not give the test time, the time is the result of multi-negotiation. Some standards have a given time, a kind of laboratory data and long-term use of the data comparison results, such as most of the automotive standards.
4, the amount of irradiation doubled the test time can be reduced by half? (Is Joule equivalent?)
Often people ask if only consider the irradiance factor, the original irradiance 0.55 w/m2 need to do 2000 hours, if the irradiance increased by 1.1 w/m2, is not only need to do 1000 hours, in fact, this idea is not right, light aging a slow light aging process, which may contain light reaction, oxidation reaction, mechanical action, temperature and humidity, etc., although improve the irradiance can be a certain degree to improve the reaction activity. Although increasing irradiance can improve the reaction activity to a certain extent, but not this reaction is not superimposed according to the ratio, the pursuit of speed may deviate from the meaning of the test itself, resulting in the deviation of the test results from the actual. The following comparison data is a good illustration of this point.
5、What kinds of light aging tests are there? How to choose?
At present, there are three main types of light aging tests: UV aging, xenon aging, and carbon arc lamp aging
(1) rapid ultraviolet aging (QUV): the corresponding test equipment is UV Accelerated Weathering Tester, UV wavelength is generally between 290 ~ 400nm, in the short-wave UV band can better simulate sunlight, short-wave UV usually causes aging of polymers, such as loss of light, strength, yellowing, cracking, embrittlement, and its lamp Spectral stability, it changes over time the spectral power distribution changes very little can improve the test reproducibility and repeatability, in addition to do a better job in simulating outdoor humidity, its condensation system (100% RH) than the xenon lamp water spray more intense and real. Its deep penetration can cause damage to do, such as surface blistering of coatings, cracking, corrosion, etc.
(2) xenon lamp aging: the corresponding test equipment is Xenon lamp aging test chamber, xenon lamp is mainly simulated sunlight, its wavelength is generally between 400 ~ 800nm, in the long-wave ultraviolet band and visible light band simulation effect is better, long-wave ultraviolet and visible light will make pigments and dyes fade and color change, so when the product is concerned about color change We generally recommend the use of xenon lamps, in addition, because the xenon lamp filter is able to simulate through the glass window and other special conditions, and thus the indoor conditions are generally selected xenon lamps.
(3) carbon arc lamp aging: the corresponding test equipment is carbon arc aging tester, carbon arc lamp simulation accelerated aging tester is the first to appear, because of high maintenance costs, can not be corrected, simulation of the narrow spectral range and other shortcomings, now in addition to some Japanese companies due to the large amount of data accumulated in the early carbon arc, but also in the continuation of the use of the outside, less and less people use. However, in recent years, some Japanese companies are also trying to switch to xenon lamps for testing.
6, light aging test before which parameters need to be confirmed?
There are two cases as follows.
A. If there is a standard, please provide the standard number and test time
B. If there is no standard, please provide the following information.
(1) Confirm which light source to use for the test? Generally determined by the purpose of the test or recommended by the standard on which it is based.
(3) Which filter to use? UV aging considerations for the selection of filters, xenon lamps must be used in accordance with the conditions of the product to select the filter or recommended by the standard.
(4) temperature, black plate temperature or black standard temperature.
(5) Is it sprayed? According to the conditions of product use to choose.
(6) Test time, decided by consultation, can refer to point 3 of this article.
(7) Other information, such as humidity, chamber temperature, circulation control, etc.
QINSUN is a manufacturer with many years of manufacturing and production of Xenon lamp aging test chamber and UV aging test chamber, our aging equipment in line with international standards, advanced aging test methods, welcome to buy!