[China Aluminum Industry Network] With the gentrification of the living environment, new heat-insulating aluminum alloy profiles have been introduced from abroad to China. Each aluminum profile production company has introduced foreign thermal break bridge wear strip equipment, and domestic enterprises engaged in aluminum processing equipment have also developed thermal break bridge wear strip equipment. All hope to push the new type of heat insulation aluminum extrusion market. The production cost of insulation aluminum profiles is higher than that of ordinary aluminum profiles, which increases the number of processes such as through-oxidation, spraying, and stripping. Through the connection of the broken bridge, the silver oxide white material can be connected with the color spray paint, the sand fabric and the coloring material, and the decoration of the profile can be increased. The specific conditions are briefly explained below.
1. The insulation principle of heat insulation aluminum profiles The heat insulation wear aluminum profiles are composed of aluminum alloy profiles and thermoplastic heat insulation strips. Rolling heat insulation aluminum alloy profiles are made of high-density heat-insulating polyamide PA66 rubber strips or PVC hard plastic plastic strips that are rolled and rolled to form aluminum and plastic. The foamed heat insulation aluminum profile is the use of heat insulation strips to connect the inner and outer aluminum profiles into one body, fill the formed insulation cavity with polyurethane foam, and become a “cold bridge†of heat insulation aluminum alloy profiles, achieving insulation Energy-saving effect.
2. Production process Domestic heat insulation aluminum production line, the main production technology is the use of "roll embedded", whether it is the introduction of foreign or domestic equipment, are using the "three-step method" production process, that is, open teeth, Wear strips and roll. Some companies are also studying the “two-step process†production process, which will open the teeth and wear strips simultaneously, but the basic principles are the same, but the process time is shortened.
The technological process is: operating platform on the profile → sticking the protective film → opening the teeth → wearing the strips → roller pressing → filling the polyurethane foam with insulation chamber → packaging.
(1) The main process is mainly to inspect the surface quality and dimensional specifications of the profiles. Inner and outer aluminum profiles can be anodized or electrostatic powder coated. It is also possible to use different color ingredients for the inner and outer aluminum profiles, and to connect the inner and outer aluminum alloy doors and windows with a broken bridge.
(2) The second process is to stick the protective film. The surface quality of the main protection profile is not damaged during processing and handling.
(3) The opening process is a key process, and the main process is to form a zigzag tooth path by rolling the inner walls of the insulating aluminum profile stripping slideway. The PVC rigid plastic strips are embedded by roll pressing.
At present, there is no specific provision for tooth depth, but in the industry standard JC/T building heat insulation aluminum alloy standard. The tensile strength and shear strength values ​​are specified (see Table 1), which requires that the toothed path must be tightly connected to the PVC rigid plastic insulation strip and the aluminum alloy profile by a roller.
(4) The tying and rolling process is an important process. The slivers are made of PVC rigid plastic heat insulation strips and are threaded into the toothed heat-insulating aluminum profiles through the splicing equipment (see Figure 2). Then, by means of a roller press, the heat-insulating aluminum profile and the PVC rigid plastic strip are rolled together.
(5) The process of filling the polyurethane foam in the insulation chamber is for the foam insulation aluminum profiles. The profiles are placed in a two-component metering mixer and poured into the insulation cavity through the mixing nozzle to be naturally foamed.
Polyurethane is an abbreviation for polyurethane. High-molecular compounds containing many repeating groups in the polymer backbone, collectively referred to as polyurethanes. The thermal conductivity is particularly low, with excellent acoustic, electrical, and chemical resistance properties. Foam-type insulated aluminum profiles have double insulation effect and are suitable for cold areas.
(6) The packaging is a later process, and it can be packaged with plastic film, and can also be wrapped with wrapping paper. The main reason is that the protection profile is not scratched during transportation and processing.
3. Verification of thermal insulation profiles and verification of thermal insulation effects (1) In addition to meeting the requirements of GB/T 5237-2000, the insulation aluminum alloy profiles need to be subjected to conventional shear strength and transverse tensile strength testing, combined elasticity. And combined moment of inertia detection. Here only the main and complex inspection items are introduced. For specific detailed inspection items, please refer to the JG/T Building Insulation Aluminum Alloy Profile Standard in the industry.
Shear strength test: Take (100±1)mm long composite heat insulation aluminum alloy profile, and store it in (23±2)°C and humidity of 45%～55% for two days, and the effect will be obtained through the shear strength tester. The force is evenly pushed to the profile section, the feeding speed is 1 to 5 mm/min, and the applied load and the corresponding shear deformation number are recorded. Shear strength calculation formula:
Where: T - shear strength;
F1max - greater shear resistance;
L - sample length.
The combined elasticity value is the ratio of the force and displacement H in the shear failure unit length and is calculated according to the formula:
K=F1/(H×L)
Where: K - combined elasticity;
H - the displacement resulting from the shear force F(N), in mm;
L - sample length;
F1 a shear resistance.
Transverse Tensile Strength Test: The transverse tensile strength test is performed after the failure of the shear force. After the 2mm displacement occurs between the inner and outer aluminum alloy profiles, the shear force fails. Through the horizontal tensile strength tester, the effect is evenly applied to the inner and outer aluminum alloy profiles of the heat-insulating aluminum profiles, and they are outwardly stretched. Horizontal tensile strength calculation formula:
Where: Q - transverse tensile strength;
F2max - greater tensile strength
L - sample length.
(2) Verification of heat insulation effect:
Test (1). Take the heat insulation aluminum alloy sample 100mm long, clamped with a bracket, the two galvanic digital temperature display probes are close to the inner and outer aluminum alloy surface of the heat insulation aluminum profile. Bake the inner profile with an alcohol lamp, observe the temperature display and record it.
Test (2). On-site tracking of the room where the heat-insulating aluminum profiles have been installed, and through the winter and summer seasons, the changes in temperature were measured and recorded, and the heat insulation effect was observed.
It can be seen that if there is air-conditioning and heating equipment in the room, the indoor constant temperature can be maintained, thereby saving energy and making people feel good.
Insulation aluminum alloy building heat transfer coefficient detection: thermal conductivity test detection by thermal conductivity tester. Heat transfer coefficient calculation formula:
â–³T=(W/m2)
Where: â–³ T - heat transfer coefficient;
W - heat / W;
K - Calculate the temperature difference coefficient;
M2 - heat insulation aluminum alloy area.
4. Application of heat insulation profiles in the construction industry Through the innovation of various enterprises and engineering technicians, heat insulation aluminum profiles have been widely used in the construction industry. In addition to heat-insulating aluminum alloy profiles for doors, windows, and curtain walls, the company has developed automotive insulated aluminum alloy doors, windows, and furniture wardrobes for insulated sliding doors, as well as R&D for freezers and refrigerators. It can be seen that the heat insulation aluminum alloy profile will be a new type of heat insulation material with great development potential.
Feton Corporation , https://www.ultraplantleds.com