Why do some compound well covers have steel bars in them, while others don't? Let's talk about it today. First of all, the production process of well cover is generally divided into hand paste process and molding process. The hand lay up technology refers to the manual production, so the bearing capacity of the hand lay up well cover is general, which is only suitable for the use of green belt, without competitive advantage, and has been gradually eliminated by the market. Then there is the molding process. At present, most of the well cover enterprises use the molding process. The structure of the well cover made by this process is relatively compact, with high bearing capacity, and it is pressed under a certain temperature and pressure.
At present, the product structure of resin composite well cover is mainly divided into flat bottom type, ribbed type and fish belly type. From the stress structure analysis, the fish belly structure is economic and reasonable, saving raw materials and simplifying the mold at the same time, it can greatly improve the bearing capacity of the well cover. The reinforced material of BMC well cover is short fiber of 10-50mm, and the strength of short fiber is only 20-30% of continuous fiber, so it is difficult to make the bearing capacity of well cover meet the requirements of use only by using short fiber. In this case, adding steel bar can obviously improve the bearing capacity, but because the material of steel bar and composite material is very different, its thermal expansion coefficient is poor The difference is large. The surface of the manhole cover with reinforcement is easy to rust, which leads to poor combination of the surface and resin. In terms of service life, this method is not ideal. However, the bearing capacity of the SMC manhole cover with continuous fiber reinforcement is much higher than that of the short fiber BMC manhole cover with reinforcement, and the service life is more guaranteed.
With the increase of the usage of the well cover, we must pay attention to the safety of the well cover. The purchaser must select the appropriate well cover according to the environmental demand, so that the well cover can play its due price