久久激情5月丁香伊人_αv中文字幕女人乱码在线_成年人看的毛片在线观看_国产上床视频_精品亚洲国产黄片_三级日本黄页网站大全_国产美女精品网站_在线观看中文综合亚洲_男操女视频免费_亚洲中文字幕无码永久

(1) light product quality: the specific gravity of engineering plastics is generally about 0.83 ~ 2.2, only 1/9 ~ 1/4 of steel and 1/2 of aluminum. Some engineering plastics, such as polypropylene, are much lighter than water. This characteristic of plastics is of great significance to the mechanical equipment that requires to reduce its self weight, such as vehicles, ships and aircraft.

(2) high specific strength: for materials with equal volume, the strength of engineering plastics is generally lower than that of metal. However, because engineering plastics are much lighter than metal, when compared with equal weight, the strength of some engineering plastics is much higher than that of general metal, which is the highest strength material in the existing structural materials. For example, the tensile strength per unit weight of glass fiber reinforced epoxy resin is about 2 times higher than that of ordinary steel.

(3) good chemical stability: engineering plastics generally have excellent corrosion resistance to acid, alkali and other chemicals, which is a very significant advantage. Among them, polytetrafluoroethylene and polyether chloride have excellent corrosion resistance, and have broad development prospects in chemical anti-corrosion equipment.

(4) excellent electrical function: almost all engineering plastics have superior electrical insulation function, minimal dielectric loss and excellent arc resistance, which can be compared with ceramic, rubber and other insulating materials. Therefore, the application of engineering plastics in motor, electric appliance and electronic industry has a very broad prospect.

(5) excellent friction reducing and wear-resisting functions: by using this feature, various self-lubricating bearings, gears and sealing rings can be made of engineering plastics. Engineering plastics also have excellent embedment to foreign matters, which is particularly important for their application in the harsh conditions with abrasive particles or impurities.

(6) excellent shock absorption and noise elimination effect: machinery equipped with engineering plastic bearings and gears can reduce vibration, weaken noise and even achieve noise elimination.

(7) convenient forming and processing: engineering plastic products can often be formed at one time, while metal products have to go through several, dozens or even dozens of processes to complete the processing. This characteristic of engineering plastics is of great significance for saving man hours and improving labor productivity. The machining of plastics is also relatively simple.

This article is from Jiangmen Engineering Plastics:http://www.xrtsm.com.cn/