Current international testing standards and develo

2022-08-23
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Introduction to the current international testing standards and development of insulating glass

at present, there are two types of insulating glass performance testing methods and testing methods for evaluating insulating glass performance in the world: one is the European standard en1279 represented by the European Union, and the other is the North American insulating glass standards astme2190, astme2188, astme2189 represented by North America These two kinds of insulating glass standards have evolved from different national standards after years of practice and according to the development of science and technology, the improvement of product quality and the improvement of people's requirements for product quality. By introducing the relevant contents and development process of international insulating glass standards, this paper hopes to enlighten the revision of insulating glass standards in China

en1279 insulating glass standard before officially becoming a European standard, en1279 standard has also been coordinated with the standards of various countries for many times, and compared with the standards of many countries. After many discussions, it has finally been accepted as an en standard by most countries, the most typical being in line with the Italian national standard

the MQV mark of Italian national product certification is difficult to be accepted as a quality mark by other European countries, mainly for the following reasons: ① non compulsory certification structure (fully voluntary); ② The reference standard uni7171 is an invalid standard; ③ The additional test standards do not refer to any official standards

in order to modify uni7171 standard, the stopped part is required to connect uni to centc129. The new Italian standard will recognize the work of wg4. With the help of mrdechateau (the father of European architectural glass standard), the abolished part is recognized, and the work of "marchionui" standard can continue. In 1996, uni standard became a formal member of the quality mark of insulating glass, which gave a new impetus to the promotion of pren1279 standard, which is an important raw material for the production of polycarbonate, and made Italy a leading country to accept different parts of pren1279 standard, which also promoted the promotion and application of pren1279 in European countries

in 2000, pren1279 series of standards have been fully accepted by Italy, including the product control and periodic test in part 6, the mquni insulating glass version that has been widely recognized in the past seven years. The regulations still include documents, system description of insulating glass products (mandatory items specified in the standard rules), and the whole standard (pren1279 Series) is composed of the following parts: prEN: architectural glass insulating glass products-1: general provisions, dimensional deviation and product structure regulations; PrEN: building glass - insulating glass products -2: long term test methods and requirements for water vapor penetration; PrEN: building glass - insulating glass products -3: long term test methods and requirements for gas leakage ratio and gas concentration deviation; PrEN: architectural glass - insulating glass products -4: Test Method for physical properties of edge sealant products; PrEN: architectural glass - insulating glass products -5: compatibility evaluation; PrEN: architectural glass - insulating glass products -6: factory product control and periodic testing

the Italian standard uni regulations include many details of product structure manufacturing requirements, which are:

1 All materials used in the product must be certified. Glass: identified according to European standards and relevant standards; Spacer, sealant and desiccant: identified according to relevant parts of 1279 (valid for 5 years); In addition, the quality of each batch needs to be tested according to the corresponding procedures

2. Insulating glass products should meet the following requirements: the minimum amount of butyl rubber: at least 1.5g/m along the length of each side of the aluminum strip, so that after effective hot pressing, the width of butyl rubber is at least 3mm; The minimum thickness of external secondary sealant is 3mm; Quantity of desiccant: aluminum strips with an interval of more than 10mm shall be filled with at least 50% desiccant on each side; For aluminum strips below 10mm, at least 3 sides are filled with desiccant; For traditional aluminum strips that are not elbows, the corners must be sealed with butyl rubber; The output signal of no pressure sensor passes through two inverse closed-loop amplifiers to make the output voltage signal meet the collection requirements of single chip microcomputer. There are broken strips and glue breaks of butyl rubber and secondary sealant; For inflatable insulating glass: the gas concentration in the cavity must be measured (at least 3 samples per day); And seal the inflation hole

3. Define FPC (factory product control) and test, and follow pren1279 investigation to understand whether enterprises support circular economy -6 with practical actions. Generally, the voluntary certification system reaches the 1+ level of CPD (construction product regulations). With the initial type test, it will be checked twice a year without notice. According to prEN or prEN regulations, on-site sampling (long-term test: 4+7 weeks maturation). Therefore, in the past years, the second, third and fourth parts of pren1279 standard can be tested, including the sixth part of factory product control

from the perspective of glass structure production and product characteristics, one of the main problems that is most difficult to control is the use of embossed glass, carved glass or polished glass on the second or third side of insulating glass, because such a surface will have a negative impact on the water vapor penetration I value. The water vapor permeability I value of embossed insulating glass products is indeed higher, but it is still lower than the limited value

the second is the use of color and polyurethane spacer (PVC spacer). Butterfly bonding test shows that the bonding between color spacer and sealant is very poor. Italy has done several tests with polycarbonate plastic lattice strips, and no positive results have been obtained. On the contrary, the moisture content of desiccant always exceeds 0.25 after aging of samples made in the same factory, while the average water vapor penetration I value of pure aluminum strip insulating glass after aging test is only 0.02

for the insulating glass manufacturing factory, the common problems and problems prone to occur in the process of product quality certification and verification are: incomplete sealing of aluminum spacing (cracks); The distance between the spacer and the outer edge of the glass is wrong (less than 3mm); The quantity (at least 1.5g/m), width (3mm after pressing) and butyl rubber have poor uniformity (discontinuity) and inappropriate pressing combination; The glass and sealant are not fully bonded

the main reasons for these problems are generally expressed in the industry. First, the production of spacer bars mainly depends on the type and thickness of aluminum spacer bars; The width of the spacer bar is more than 15mm and the use of color spacer bar is one of the reasons for the frequent problems; Second, the problem of the aluminum spacer depends on several factors, such as: the position of the spacer on the glass; The wear of the support pulley of the assembly line leads to the dislocation of the spacer; Whether the spacer is square or not, especially the square control of elbow spacer

according to the analysis, there are two main factors affecting the water vapor penetration of insulating glass products: one is the butyl rubber extruder: the biggest problem may be the calibration of the nozzle and the imbalance of butyl rubber extrusion quantity on both sides of the spacer strip (the en standard stipulates that the butyl rubber extruder must be checked many times every day); The second is the type of pressing: roller press and flat press are significantly different. All vertical roller press must be improved before production, and only flat press can obtain satisfactory results. Zhonghua glass () Department

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