Foreword
     With the modern development of the booming construction industry, construction market has been the traditional doors and windows Muchuang, Gangchuang to more decorative and energy-saving features of plastic doors and windows and aluminum doors and windows. Steel doors and windows, aluminum doors and windows and plastic doors and windows by已呈Dingzu trend.
     Construction of the doors and windows, in addition to the overall requirements of a good decorative effect, but also need to have excellent insulation, noise, dust, sealing performance, and other characteristics. As one of the doors and windows of the annex, flexible plastic strips is sealed to obtain an important guarantee for excellent performance.
     In the past the use of the process, since the building with doors and windows sealed plastic strips chosen properly, a lot of quality issues, the main problems:
     1. Sealed plastic strips used soon hardens Biancui the loss of flexibility and sealing functions.
     2. Sealed plastic strips installed, falling short period of time contraction, leading to rework.
     3. By sunlight or heat, sealed plastic strips of the stick, attached to the window and glass, sometimes there will be "permeability" phenomenon, pollution of the doors and windows, doors and windows sealed affect the function and aesthetics.
     4. Due to structural reasons for sealing plastic strips of "false" installed or no sealing function.
     This shows that the choice of excellent sealing materials and the design of the structure is reasonable to solve the crux of the problem.

First, building doors and windows sealed plastic strips Summary

     1. Building the definition of doors and windows sealed plastic strips
       Building doors and windows sealed with plastic strips generally refers to the doors and windows in the building components, such as glass and pressure of the glass and fans, with fans and box fans and fans, and other digital interface, can prevent internal and external medium (water, air, dust , Etc.) disclosure, or to prevent invasive or mechanical vibration, shock and injuries to achieve sealing, noise insulation and insulation, such as the role of ribbon or rod material (Figure 1, Figure 3).
      2. Sealed plastic strips classification
     Seal of the material can be divided into rubber seal, rubber seal, plastic seal; structure of the material can be divided into solid seal of the sponge sealed, hollow seal, sealing compound (sponge and solid rubber, sponge-rubber And metal inserts, rubber and metal inlay pieces of sponge and leather, fiber and other entities), electrostatic flocking seal and the seal of the surface coating; processing technology can be divided into the curing seal and non-curing seal; their Special features can be divided into heat-resistant seal, cold seal, oil seals, anti-wear seal and vibration sealed; their use in different parts of the doors and windows can be divided into sealed glass of the box (fan) sealed , Yarn, such as fan use of the seal. It can also be divided into its transparent sealed transparent and non-transparent sealed; their decorative effect can be divided into different colors of the seal.
      3. The work of sealing plastic strips
     Construction is the main doors and windows sealed plastic strips used in the body structure flange lip cavity (see Figure 1), and other parts of the assembly flexibility and decorative pieces (glass, metal pieces or non-metallic pieces), and other contact with the surface of objects and contact pressure A seal, in general -50 ~ 70 ℃ within the scope of use.

Second, building doors and windows sealed with plastic strips Category

     At present, the system suitable for windows and doors sealed plastic strips to do construction materials three major categories: rubber, plastic and rubber blends plastic materials. Abroad mainly in rubber-based materials, respectively chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), silicone rubber (SiR) and EPDM (EPDM); domestic major modification to the main plastic materials, mainly A plasticized polyvinyl chloride (PVC), by plastic polypropylene (PP). In addition, rubber, plastics blend material in domestic and foreign are also used. Below were sealed plastic strips on a variety of materials to make a brief introduction, so we know it.
      1, the Department of rubber materials
      ⑴ natural rubber: a very good wear resistance, high flexibility and mechanical properties. Shortcomings in the air is easy to aging, Heating viscosity change in mineral oil in the expansion and easy solution, alkali-resistant but intolerance strong acid. The use of temperature range of -55 ℃ ~ +80 ℃.
      ⑵ NBR: The main feature is oil, solvent resistance, but intolerance ketones, esters and chlorinated hydrocarbons, and other media. Sulfide permanent deformation of small, flexible and mechanical properties are good. Shortcomings in the ozone and oxygen in the aging-cracking, poor cold resistance. The use of temperature range of -30 ℃ ~ 120 ℃.
      ⑶ chloroprene rubber: has good flexibility and mechanical properties, excellent light resistance, heat resistance, anti-aging, oil and corrosion-resistant chemicals, in particular its ozone-resistant properties, weather-resistant, fire and more prominent, in a very non - And solvents have great stability. Shortcomings is not cold, cold, crystal-hardening, the stability of poor storage, processing difficult to control. The use of temperature range of -40 ℃ ~ +120 ℃, the NBR can be used as substitutes.
      ⑷ EPDM: comprehensive performance, a prominent ozone resistance, weatherability good, very good resistance to high and low temperature performance; prominent drug-resistant chemical drugs, a variety of polar solute capability, such as brake oil , Strong acid strong base, alcohol and so on. Shortcomings in the general mineral oil and ester of two additional expansion of a large quantity of lubricants. The use of temperature range of -60 ℃ ~ +150 ℃.
      ⑸ silicone rubber: a prominent high-resistant, low-temperature characteristics, weather resistant and resistant to ozone-aging properties, excellent drainage and proper ventilation; has unparalleled insulation properties. Shortcomings in the mechanical strength of the rubber materials is the worst, not oil. The use of temperature range of -100 ~ +300 ℃.
      ⑹ polyurethane rubber: has excellent flexibility and abrasion resistance, good gas-tight, high damping performance, in addition to medium oil, oxygen-resistant and resistant to ozone aging characteristics. Shortcomings is not acid and alkali and water. The use of temperature range of -30 ℃ ~ +80 ℃.
2, the Department of plastic materials
      ⑴ plasticized PVC resin: cheap materials easily obtained, a corrosion-resistant, wear-resistant, Naisuan Jian, and various chemical media, burning resistance, high mechanical strength and weaknesses within the system with easy plasticizer migration, as time Biancui extended hardens, loss of flexibility, intolerant aging, weathering of the poor and low-temperature characteristics.
      ⑵ by polypropylene plastic resin: Performance and plasticized PVC similar, usually used to make the system transparent products.
3, rubber and plastics materials blend
     At present, domestic and foreign rubber used to make plastic-sealed plastic blend of materials mainly as follows:
a \ acrylonitrile-butadiene rubber / PVC and used system is used rubber and plastics technology and a pioneer;
b \ ethylene - EVA (EVA) / PVC and use system;
c \ EPDM / PVC and use system;
d \ polyurethane rubber / PVC and use system;
e \ EPDM / polypropylene and used systems, dynamic approach to curing;
f \ butadiene rubber / acrylonitrile-butadiene rubber / PVC and use system.
    ⑴ thermoplastic elastomer (TPE) thermoplastic elastomer to the matrix of plastic resin, chemical or physical means to incorporation of rubber components, thus forming a flexible and elastic rubber, plastic and rigid, is a wide range of materials. Thermoplastic elastomer (TPE) is the biggest characteristic of the need curing process, and the use of plastic molding thermoplastic processing methods, you can significantly reduce the molding cycle, but can also waste recycling and re-use, with the help of financing energy-saving, is a Promising material can be used as a substitute for vulcanized rubber.
     Thermoplastic elastomer (TPE) of styrene main TPE, that is, TPS; Olefin TPE, that is, TPO; polyurethane of the TPE, that is, TPU and polyester of the TPE, that is, TPEE, and other broad categories. Recently developed for the modification of PVC TPE of olefins of TPE, the main U.S. production of DuPont Elvalog741, 742; Goodyear production Chemigum P83 Bayer company of Germany and the Levapren. After the modification of PVC seal has good resistance to compression of permanent deformation.
    ⑵ surface coating material surface coating material is sealed in the surface coating of polyurethane (PU, including water dispersion of PU), organic silicon, Xylan or Teflon (PTFE), and other material to replace the traditional process on the surface Flocking. Seal coating the surface of the film has good resistance, smoothness, especially silicone coating the surface coating seal of the coefficient of friction on the surface, is conducive to the glass door and window fans or sliding. General polyurethane Germany, the United States and Japan use oil as a seal of the surface coating materials.

Third, building doors and windows sealed in a star - EPDM (EPDM) rubber seal

     1, excellent resistance to ozone and resistant to oxidation of EPDM the molecular structure of the main non-linked bond (Figure 2), to fully resist the attack of ozone in the air, ozone concentration is 100 PPM environment, there is no 2430 hours Cracking (500 hours cracking butyl rubber, neoprene cracking 40 hours) in 50 PPM, drawing 30 percent of the static condition, not cracking 150 hours (two hours in butyl rubber cracking). Chang and diene and flexibility of use, to improve their ozone-resistant and anti-oxidation (NR, SBR encountered, such as ozone, will cause stress cracking, and with all the physical properties of film deterioration).
    2, excellent weather can be long-term EPDM in sunlight, humidity, cold use of the natural environment. CB vulcanizate of the sun exposure in 2003 will not be cracking, and mechanical properties have a very small change.
    3, excellent heat resistance at 120 ℃ EPDM can under the conditions of long-term use, the maximum temperature 150 ℃, more than 150 ℃ at the beginning of decomposition, when the accession to the appropriate agent or peroxide Fanglao Hua, quinone curing system, its occasional resistance Temperature as high as 315 ℃. This feature is saturated by the main structure linked by the decision.
    4, the outstanding characteristics of low-temperature poly ylmethyl main chain of flexible Qu provided a good low-temperature characteristics, its glass transition temperature in the -35 ℃ - 65 ℃, and the majority of products in curing under the conditions of -50 ℃ or soft, That is, the temperature has better flexibility and less compression permanent deformation, making it the region will not be cold ambient temperature is too low and closed lower its performance, so that in the cold in the winter construction easier.
    5, chemical resistance of a variety of polar-resistant EPDM solute, such as brake oil, acid and alkali, alcohol, etc.; resistant to non-polar solute poor performance, such as gasoline and other hydrocarbon solute, and so on, through the use of ultra-filled polymer oil Circumstances will be of medium oil.
    6, high-filling (fill and oil) EPDM than any other of flexibility must be filled in much higher (up to 200 above), make up a price higher than the general common rubber (about than SBR, IR, NR high 60 %) Deficiencies. Use of ultra-high molecular weight oil-filled ethylene-propylene rubber, will not only further increase the filling, mix reduced processing costs, but also to be highlighted for the tensile strength and elongation strength.
    7, EPDM synthetic rubber is almost all in a proportion of the lightest (also below the plasticized PVC), so its products are lighter weight metres. This is also its decision to have a broad prospect.
      EPDM is in addition to the above-mentioned advantages (Table 1), and EPDM density, has excellent electrical properties, good stress - strain characteristics, good wear resistance, high humidity resistance and resistance of water vapor.
Concluding remarks
     Throughout the past few years abroad construction of the doors and windows sealed the production and application, we can see that has the following characteristics worthy of our attention.
     1. The correct choice of sealing doors and windows of the building has become a product of the process of doing must consider and address the key. Now, is not a seal of quality problems before taking remedial measures, but has deeply penetrated into the system to process products.
     2. Building doors and windows to solve the "seal" the problem alone, excellent material or reasonable structure are not solve the problem. "Structure" and "material", "Construction," "test" four, are inseparable. Rely on the old, traditional concept of choice, anywhere from the market to buy several seal is not really solve the building's windows and doors "seal" the problem.
     3. Research and promotion of high-performance seal has become a top priority. High-performance sealed plastic strips and guarantee its development of high-quality windows and doors simultaneously. Construction works on windows and doors in recent years the quality problems are mostly from low performance, poor quality of the seal.