Cast iron parts are being used for manhole covers on urban roads. Although cast iron manhole covers have many advantages, they also have the following problems: cast iron manhole covers are often lost during use, resulting in frequent accidents; Some cast iron manhole covers with larger surface areas have poor impact resistance and are prone to breakage under the impact of moving vehicles; Cast iron manhole covers are greatly affected by climate. In areas where the temperature changes significantly in winter and summer, cast iron manhole covers have a higher coefficient of thermal expansion and a looser fit, making them susceptible to overturning by moving vehicles; Although self-locking structures can only change certain functions in terms of formal structure, they are prone to loss; It is difficult to overcome phenomena such as breakage caused by impact.

Therefore, people began to explore the replacement of cast iron products with polymer composite materials. There are also many manhole covers made from waste plastics or other polymer composite materials in the shopping mall. The use of polymer composite materials to manufacture manhole cover series products must have the following advantages: ① high strength and rigidity; ② Not deformed or broken under heat or force; ③ Has high wear resistance and heat resistance; ④ Good molding process, low shrinkage rate, and good scale stability; ⑤ Low molding pressure, simple manufacturing process, extensive data sources, and low price; ⑥ It has a non retrievable function and anti-theft (non retrievable for use). The manhole covers produced using SMC materials have become the mainstream of this type of product due to their excellent functional agility. This type of product has been tested in many cities, with various functions reaching the level of manhole covers. It is both environmentally friendly and anti-theft, and has a huge market size. It is a product worth promoting. Therefore, SMC data is outstanding in the application of manhole covers for urban roads.

 

The article originates from SMC molded products: http://www.jmlicheng.com/