Aluminium windows and doors can generally judge the quality from raw material (aluminum) materials selection, aluminium profile surface treatment and internal processing quality, the price of aluminum doors and windows, etc to make roughly judgment.
First see the material. Superior aluminum used in the aluminum doors and windows, thickness, intensity and oxidation film, etc, should comply with the regulations of relevant national standard, aluminium window profiles main stress bar wall thickness should be in 1.4 millimeter above, aluminum door profiles main stress bar wall thickness should be in 2.0 millimeter above, tensile strength of millimeter of every square metre reach 157 Newton, the yield strength to achieve every square millimeter 108 Newton, oxidation film thickness should achieve 10 micron. If it couldn't reach the standard of above, it is inferior aluminium doors and windows, cannot be used.
Second see the process. High quality aluminum doors and windows, fine processing, exquisite installation, sealed performance is good, switch freely. Inferior aluminium doors and windows, blindly choose aluminium profile series and specifications, processing manufacture in a rough way, use saw cutting replaces milling process, not according to the requirements for installation, sealed performance is poor, the switch does not freely, not only rain or air leak leakage and appear glass blast crack phenomenon, but also while encounter strong breeze and outside force, blow push-pull part or glass easily fall or touch fall, destroy content cuts.
Third see the price. In general, high quality aluminum doors and windows for the production cost is high, price is higher than inferior aluminium doors and windows about 30%. Some aluminum doors and windows which made from aluminium profile that wall thickness only in 0.6-0.8 millimeter, tensile strength and yield strength is much lower than the relevant state standards, using very insecure. In addition, more are self-employed entrepreneurs processing of aluminum doors and windows; they do not know the structure characteristics and properties of aluminum doors and windows. In order to reduce cost they jerry-build, shoddy, the hidden trouble of the product is big, should not be commonly use. So you had better choose normal aluminium window and door manufacturers products.
Forth see the material. On the material using there are mainly six aspects can refer to:
1. Thickness. Aluminium sliding doors and windows have 70 series and 90 series two kinds, residential interior aluminum sliding door can use 70 series. Aluminum alloy series number show the thickness of the door frame millimeters of structure sizes. Common aluminum sliding windows have 55 series, 60 series, 70 series, and 90 series four kinds. Selection should be according to the size of humanly scaled and local wind pressure value, Used as aluminum sliding window of the closed balcony should not be less than 70 series.
2. Strength. Tensile strength should achieve every square millimeter 157 Newton; Yield strength should achieve every square millimeter 108 Newton. When choose and buy, can moderate bending the profiles, they should be able to back after let go.
3. Color. The same aluminum profile color should be consistent, if color has difference obviously, namely that, unfavorable choose and buy.
4. Flatness. Check the surface of aluminum profiles should be no dents or bulging.
5. Glossiness. Aluminum doors and windows should avoid the choose and buy aluminium profiles which have open defect such as the surface has open air bubbles (white) and ash (black), crack, burr, peeling etc.
6. Oxidizability. Oxidation film thickness should achieve 10 micron. Light scratch on a material surface when choose and buy, see if the surface oxidation film can be erased.