Composite resin manhole covers are suppressed
1. Product features of composite resin manhole cover
（1）. Light weight, the weight of the glass steel manhole cover is about 1/4 of the iron cover, the engineering installation and use of the opening and closing are light and flexible;
（2）. Good self-locking. The unique constrained connection structure of the glass fiber reinforced plastic round manhole cover and the well seat has a self-locking function to prevent the manhole cover from jumping off the well seat after the car passes by;
（3）. High strength. The tensile strength of FRP materials is equivalent to that of Q235 steel, and the compressive strength is more than twice that of C30X. Its impact, vibration, fatigue, and fracture resistance are better than steel, iron and other materials. It is used as a bearing structure of the manhole cover , Strength and safety conditions are easier to meet than iron manhole covers;
（4）. Anti-theft and loss, FRP products have no waste recycling value. Used as a manhole cover can avoid the hidden danger of steel manhole covers from being stolen, thereby preventing man and vehicle traffic accidents caused by manhole cover theft and reducing economic losses and accident liability.
（5）. Corrosion resistance, glass fiber reinforced plastic material is naturally corrosion resistant. It is used as a manhole cover for acid, alkali, salt, sewage and other corrosive medium environments. It has technical and economic advantages.
2. The main purpose of composite resin manhole coveris mainly used for municipal roads, water supply, power supply, post and telecommunications, street lights, residential areas, garden planning, oil and gas exploitation, chemical production, sewer cover, environmental sanitation and other engineering projects, mainly divided into the following three types:
（1）. Heavy: the road or parking place where motor vehicles pass.
（2）. Light duty: green spaces, passages, bicycle lanes or sidewalks where motor vehicles are not allowed to enter.
（3）. Ordinary type: roads or parking places where cars of class 10 and below pass.
3. Compound tree manhole cover production equipment
The production equipment of composite resin is mainly a composite manhole cover hot-press forming hydraulic press. The commonly used specification is a 315-ton four-column hot press. In addition, peripheral equipment such as kneaders and molds are required; specifically, the raw materials are prepared by the kneader. BMC molding compound (BMC), the material is heated at this time, and then quickly cut the mass to bear the weight, place it in the mold cavity heated to a specified temperature (usually about 140 degree ), and then the press slide beam quickly Press down to close the mold, hold the pressure (the pressure hold time depends on the thickness of the manhole cover), eject the mold and obtain the finished product.
