Analysis of the gap between China and Germany in t

The gap between plastic doors and windows between China and Germany is analyzed from three perspectives

in real life, the application of plastic doors and windows can be seen everywhere. The technology of German doors and windows is mature and suitable for China's national conditions. Therefore, the gap between plastic doors and windows between China and Germany is analyzed from three perspectives

there are two major systems of PVC plastic profiles and plastic doors and windows in the world, mainly the European system represented by Germany and the North American system of the United States and Canada

1. There is a gap in basic research and management

the production of plastic doors and windows in Europe began in the late 1950s, with a long history, a relatively perfect standard system, strict standards, and national standards tend to be based on European standards. Most enterprises in Germany have physical performance testing equipment for doors and windows. They have carried out their own research and accumulated a large amount of data. During the preparation of the standard, the key data are analyzed after a large number of experiments. According to the French Construction Technology Research Center (CSTB), the center has an organization responsible for the certification of plastic doors and windows, including the certification of mixed raw materials, the certification of profiles, the license of door and window design, and the certification of door and window enterprises and their products

in contrast, many data of China's corresponding standards are also from European standards, but the source of data is often unknown. In addition, the standard system is incomplete. For example, in the case of large indoor and outdoor temperature difference, there is no standard to detect the physical performance index of the deformed outer window and the anti-theft standard of the outer window. The standards for profiles and doors and windows were organized and formulated by the former Ministry of light industry and the Ministry of construction respectively. The incongruity between the standards also caused some difficulties in quality supervision. In China, most PVC plastic profiles and door and window enterprises do not have physical performance testing equipment for doors and windows, and the research carried out is not deep enough, lacking the accumulation of door and window use data

2. There is a big difference in design power and product level

architectural design lacks novelty and creativity. European style buildings are not the same in design. There are French style houses and Italian style houses, and American style buildings are also divided into South America and North America, so that the plastic door and window design is coordinated with the external facade of the house. This multi system architectural style is related to national, historical, cultural, climatic and other conditions, and is formed in the long-term development process

domestic products tend to be similar and lack novelty. In the plastic door and window market with a large increase in number, their varieties have not increased correspondingly, but have a tendency to become increasingly single. Most manufacturers copy the European system, and the cavities imitate each other, lacking novelty and creativity, which will transform into price competition with the same cavity and window type, which will inevitably hinder the development of the plastic door and window Market in the future

founded in the late 1950s, the joint-stock German door and window Research Institute has complete testing equipment and has accumulated a large amount of data for decades, which can be used as a database for enterprise development. Each large-scale enterprise carries out independent research and development. For each new window type, the cavity design, hardware matching, and physical and mechanical properties are all considered in the design. The products of each enterprise have their own technical characteristics and are not copied. All the technologies produced in China, such as flat open lower hung windows, lower hung sliding doors, folding doors, and lifting sliding doors, originate from Germany. When importing equipment and technology, Chinese enterprises often ask each other to design doors and windows. Once they are pushed open in the market, other enterprises without design ability have asked mold factories to imitate mold production, and the products are the same. Because they are not their own technology, they lack the guidance of secondary design needed in door and window engineering

in addition, the development cost of plastic doors and windows is high and the cycle is long (generally, the cost of a series of molds is hundreds of thousands of yuan or millions of yuan, and it takes nearly half a year to make and debug successfully, which is beyond the average enterprise's ability to afford), which restricts the development process of plastic doors and windows in the Chinese system. In recent years, some domestic enterprises have also undergone some gratifying changes. They have carried out research on the technology of doors and windows, and have independently developed some new products to complete the tensile, contraction, zigzag, shear and other mechanical property experiments of samples. However, from the perspective of the industry as a whole, they still can not meet the development needs of the industry. We must aim at the development direction of building energy conservation in order to ensure the sustainable and healthy development of enterprises and industries

from the aspect of energy-saving standard requirements for external windows, the heat transfer coefficient K of external windows in Germany is ≤ 0.6-1.1w/(㎡.K). The main technical means is to increase the thickness of PVC plastic profiles and increase the insulation chamber, generally 5-7 insulation chambers. Some insulation chambers are filled with polyurethane foam, and modified PVC plastic profiles that can replace reinforced steel are developed; In terms of glass, Low-E insulating glass filled with inert gas is used, and vacuum is consistent with insulating glass; In terms of sealing, EPDM sealant strips or silicone rubber sealant strips are used. Because the building energy-saving standard in China is not high, only some cold regions stipulate that the heat transfer coefficient K of external windows should be less than 2.0w/(㎡.K). The domestic technical measures are to use four chamber profiles and three seals. Due to price reasons, Low-E insulating glass is rarely used. The double insulating glass of three-layer glass is commonly used, and the surface contacted with the sample adopts sticky soft rubber and other glasses. Due to the small thickness of domestic profiles, the air layer in most insulating glass is 6mm or 9mm, the performance of insulating glass is poor (theoretically, the air layer thickness of insulating glass is better when it is 12mm), and the innovation level is significantly lower than that in foreign countries

3. Differences of enterprises (personnel, equipment, management)

many workers in German door and window assembly plants are students from technical schools, with high quality, low mobility of workers, serious work and good product quality. Chinese workers generally have not received formal training and their work quality is low. Except for a few factories, the product quality generally cannot reach the level of Germany

in addition to the technical quality of workers, the accuracy of assembly equipment in domestic door and window factories varies greatly. Most of the mechanical equipment used by the profile factories of some European multinational companies are products of the 1980s, but the profiles produced are better in quality and appearance than those of Chinese enterprises equipped with more advanced mechanical equipment in the middle and late 1990s. The main reason is the difference between production and quality management. Standardize and improve the service items and capabilities of third-party institutions, such as: the inspection items and times of profile factories with continuous production are higher than those of Chinese enterprises; Door and window enterprises are generally equipped with physical performance inspection equipment for doors and windows, while China's door and window enterprises have been relying on caliper, tape and steel ruler for inspection

in Germany, in recent years, due to the development of information technology and the development of a new material application by Shanhui fan of Stanford University who integrated manufacturing systems, the concentration of door and window assembly plants has increased and the number of factories has decreased. Now the assembly plant is large in scale, with a production capacity of more than one million square meters. Some original small enterprises have become distributors of large enterprises. The direct effect is to reduce the product cost and improve the product quality

China's door and window factories are generally small. Generally, the annual production scale of door and window factories in large cities can reach 100000-300000 square meters, while there are only 50000 square meters or less assembly plants in small cities. The application of integrated manufacturing system has just started. The application equipment level of integrated manufacturing system is low, and the vast majority of them are single machine production, with low efficiency and poor quality. In developed countries, the proportion of high-performance system doors and windows has reached 70% of the total use of doors and windows, while in China, high-performance system doors and windows account for only 0.5% of the total use of doors and windows. It can be seen that China's plastic steel door and window products have a lot of room for upgrading