Kinds of aluminum and quality requirements of aluminum goods
Basing on polishing way of product surface, there are three types of aluminum on the market, white polishing, light, we can see on surface dimly the tiny veins with certain rules, and they are the most common kinds of aluminum, with cheap price.
Polishing aluminum goods, surface is shinning like mirror, clearly light reflection; softly touching can also left traces. There are no differences in quality and using value of these two types, but each kind has its own beauty that depending on the preference of consumers. In addition, there are also types of white washing aluminum, with clear white and silver, protective film layer is rather thick, much more durable using. To protect aluminum and create various colors for the product, it is now also painted by electrostatic on aluminum goods, creating aluminum goods with a special design.
Products of these types are made from aluminum foil, processed by pressure (different from cast aluminum products, with many impurities) and the processed surface. If processing by polishing, we will have kind of shiny aluminum goods. Using oil sandpaper to polish on the aluminum surface, oil will create a protective film layer.
If processing by white washing, we will have kind of silver-white aluminum goods. White washing is used soda (NaOH) and acid nitric (NHO3) to act on the goods surface, forming a thick aluminum oxide layer (Al2O3) to protect the inside aluminum.
Every high quality aluminum goods must achieve the following three requirements:
- No defects that affecting to using time, such as: blisters, dents, cracks ... especially the disabled case stands in the bottom part of the product or the same place, but the two sides have defect.
- Defects only affect to the beauty but do not affect to the durability, such as: sunspots, uneven horizontal and vertical strips ... also tobe limited. Limited level depends on levels and kinds to decide.
- Structure of parts must be balanced, durable and stable, easy to use (For example: straps, handles, lid of saucepan, pot, the assembled details of the door are not disordered, loosen) welding connections must be tight
- In addition, we can check size, thickness and weight of items to compare with standard samples (especially items are used in construction.)
Points need to note when preserving and using aluminum:
- Do not use glue or chalk to write on the surface of aluminum goods due to aluminum corrosion elements in glue and chalk, and also do not use aluminum tools to cook, wash clothes with soap because aluminum only can withstand the effects of slight alkaline type in certain extent. Similarly, do not use soap to wash regularly because it will make aluminum old quickly and destroy the shiny surface.
- However, aluminum has a higher melting temperature than tin, zinc, but aluminum goods are generally thin, if it often contact with high temperatures, it will be easy tobe soft caused to warping, distortion. Therefore, it is better to avoid cooking aluminum pots on the too hot stove.
- Do not use sand, gravel, ash or metal scrubber, hard object to hit, scrape aluminum pots for shinning and nice. Because it will loss aluminum oxide layer for outside protection. If you scrape many times, this aluminum oxide layer disappears, oxide in the air will react with aluminum and it will create another aluminum oxide layer to replace, aluminum goods are getting thinner and thinner and rapid perforation.
- In case of aluminum goods are sticked with oil, grease, mucus. It is simply to wash with hot water, soak for a while, and then gets soap cloth to wash, at last using water to clean clearly. You can also use thick rice water or tea residue to wash the left mucus.
- If the surface of aluminum has white spots, it is better to use vinegar with 40% concentration to drip on it, after few minutes, getting a soft cloth to clean, not keeping so long, it will corrode aluminum goods with small holes.
- The disadvantages of aluminum is not withstanding with the acidic substances such as vinegar, lemon, star fruit, acid, salty substances such as fish sauce, salt, and calcium, sodium ... These substances corrode aluminum, reduce the life of aluminum. Therefore, do not use aluminum goods to keep or contain food and utensils have the above substances in a long time. Do not contain food that has acidic (sour soup and pickles) or salty foods (meat, fish...) over night, because these kinds of food can corrode aluminum and dissolve a part of aluminum into food. Cooking, frying, frying foods with aluminum tools, but after that it is better to move to other containers (bowls, ceramic dishes ...)
- Because aluminum is thin, easily distorted, easily perforated, so when using, avoiding dragging them on the floor or rubbing, strong collisions with other solid things. Do not high pilling aluminum too heavy, too tall or put heavy objects override on aluminum goods, it is very easy to make aluminum goods break down quickly.
- If aluminum goods have gray and white salt, it is better to clean clearly before using to cook.