[China Aluminum Industry Network] Aluminum alloy curtain wall as a building's external protective structure, because of its dual function of decoration and structure, its material relative to the concrete structure, the material cost is higher. With the continuous maturation of the curtain wall industry market, the unit price of the curtain wall is also getting lower and lower. How to do a good job in cost control and strive to win large profits in the low price situation is already a concern for all current curtain wall companies. The curtain wall (aluminum curtain wall, glass curtain wall, stone curtain wall) composed of various forms is often inseparable from the glass curtain wall. In the unit price of glass curtain wall, the material cost of common plate (such as 6mm tempered coated glass or 6T+9A+6 coated insulating glass) accounts for about 20%~30% of the unit price, and the aluminum material (silver white material) also occupies the unit price. 20% to 33%, how to reduce the cost of expensive aluminum has become an important part of reducing the cost of the curtain wall. Material plan When the design is more economical and reasonable, the key task is to make scientific and accurate procurement planning and nesting production. Due to the diversity of façade changes in the façade, the length of the main keel and the horizontal keel is also varied. The main keel has a high linear density. When planning, the length of the main keel is generally measured at the required length. When horizontal keel or other glass frame, window frame material and other materials are under the material, the standard length of short-term material should be made into a long material with several short materials to facilitate production and processing, and each short material should be added with 4~10mm Cutting losses, partially cut-angled aluminum materials are sometimes affected by less advanced processing equipment, and each short material requires a cutting loss of 20 to 30mm. At present, when the aluminum factory is in the alumina material, the two ends are left with the aluminum wire used for suspending the aluminum. The black marks that can not be removed are generally 3~5mm from the end of the aluminum. The increase of 7 ~ 10mm cutting residual material, such as the required horizontal keel: 1100 × 200, then you need to order the long material should be (1100 +8) × 5 +80 = 5620mm, a total of 40. The length of the long aluminum material is limited by the condition of the manufacturer's oxidation tank. The general length should be controlled within 6.3m, and individual manufacturers can achieve 6.7m, but the long material is not convenient for transport. In the case of stretch-bend profiles, under normal circumstances it is not possible to order lengths exceeding 6m, as some stretch-bend machines (even imported machines) can only pull up to 4.6m due to the influence of the bending machine's own machining range, while the Lidola bend in Foshan The pull length of the factory is longer and pulled up to m. At the same time, a 150-200mm allowance should be set aside for the fixture at each end of the long material (deformation due to the clamped position can no longer be used). If the aluminum material is to be sprayed, it should be indicated on the purchase plan sheet that the material is a light body material so as not to be oxidized together with the other materials on the sheet. Due to the oxidation of silver on the surface of the aluminum material, unless the oxide film is washed off again, the coating applied on the silver material will not be able to guarantee the quality of the coating because of the low adhesion to the surface of the aluminum material. The sprayed profiles are generally provided with spare parts of 10~20mm at both ends on the basis of the required length as backup positions for the manufacturers. The larger length of spray paint is also different from that of spray painters. Some manufacturers have long sprays of only 4 meters and some can spray to 6 meters. Therefore, these conditions should be considered in advance in the material planning in order to guarantee the material Department of accurate processing. From the aluminum plant scheduling and material transportation of the curtain wall company, the aluminum plan should be produced and transported in batches. Therefore, the procurement plan for aluminum materials should avoid the ordering of materials with fewer models and fewer quantities. During the processing of aluminum materials, due to the actual conditions of the construction, there will be inconsistencies between the specific material size and the plan, but the higher material utilization rate should be followed. Aluminum nesting can now replace manual nesting with some software such as ALCAD's wire optimization system. In the long-term construction, there will be a lot of cases where the curtain wall companies will suffer material losses due to material errors (small tens of thousands, as many as several hundred thousand). Unloading (planning) is a relatively cumbersome and meticulous task. At present, in order to reduce losses in this area as far as possible, some large companies have set up specialized engineering and technical personnel to check this. In addition to reviewing the blanking dimensions of the project department, they are more reasonable in the use of materials. Optimization, which is also a measure of cost control. Purchasing control The importance of choosing a high quality and low cost manufacturer in saving material costs is self-evident. Prior to the material ordering, negotiate with the manufacturer, strictly control the deviation range of the material, irregularly check the thickness of the aluminum material, and ask the manufacturer to make corrections. If this work can be done well, it can save a very considerable annual cost. . For example, the allowable deviation of 3mm aluminum is ±0.28mm. When the positive deviation is large, the deviation weight is about 0.28/3×100% of the theoretical weight = 9.3%. If the deviation can be controlled and +0.1mm, the deviation weight is Can save (0.28-0.1) / 3 × 100% = 6%, according to the annual production of 100,000 glass curtain wall, each need 10Kg aluminum, per kilogram of aluminum according to 20 yuan, then save 10X10X per year 6%×20=1.2 million. It is worth mentioning here that the gross weight of aluminum packaging can reach 1% to 6%. When aluminum is only packaged in plastic film, a ton of aluminum has a weight of 10 kg for the weight of the packaging paper (ie, 1%). When the aluminum is packaged with a heavy waterproof paper, there are 50 to 60 per ton of aluminum. Kilograms are the weight of the package. If it is agreed with the manufacturer that only lighter packaging is used, the same calculation as above will save 10×10×(6%-1%)×20=100 million each year. Semi-finished product protection Due to the fact that curtain wall construction often cross-works with other construction units, the protection of the decorative surface before or after installation of the aluminum material (paste protection film) is to guarantee the appearance quality of the curtain wall product, and also to avoid the material being replaced due to pollution.