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Why choose composite material for manhole cover?

Author: Site Editor     Publish Time: 2021-01-05      Origin: Site

Composite material manhole cover do not is plastic manhole cover

With the advancement of urban construction process, the demand for manhole covers has surged. The disadvantages of traditional metal manhole covers and cement manhole covers are becoming more and more obvious, and new materials have become the first choice for urban construction and are widely used. Among them, the composite material manhole cover can be considered as a rising star, because the product shape beautiful become a unique landscape in the city.

Despite this, it is possible that the lack of popularization or the entry of composite materials into the manhole cover market has break the balance within the market itself, and there seems to be some misunderstanding of composite manhole covers in society, industry and the public.

There are many people ask that ‘is a composite manhole cover a plastic manhole cover?’ It means that some misconceptions about composite manhole covers have been deeply rooted in people's minds. In fact, the composite manhole cover is made of polymer as the matrix material, adding reinforcing materials, fillers, etc., through a certain process composite manhole cover, and is not the plastic manhole cover that everyone talks about.

Many people is not knowing about composite manhole covers and mistakenly confuse them with plastic manhole covers and take it for granted that composite manhole covers have poor pressure-bearing capacity, which is also a common misconception. On the contrary, composite manhole covers have excellent resistance to bending and stretching because of the superiority of the material itself, so they are very good at bearing pressure. And the composite material manhole cover also has the advantages of anti-theft, beautiful, long service life .... The advantages of composite manhole covers are incomparable to those of other materials.

However, some manufacturers reduce the cost of composite manhole covers by lowering the resin and glass fibre content for personal gain, leading to easy breakage and poor pressure-bearing of composite manhole covers, and causing a series of accidents. The market is full of BMC plus steel products, poor quality composite products also have the same problem of easy breakage and lack of pressure-bearing capacity.

In the long run, the public formed a "composite material manhole cover is plastic manhole cover" such a concept. In fact, it is not the composite material manhole cover itself has defects, pressure is not enough, but the composite material manhole cover when the development of uneven, product quality mixed, the user is easy to buy does not meet the specifications of substandard products.

Therefore, users still need to seek formal channels and formal manufacturers to purchase composite manhole covers. Ltd. is a national high-tech enterprise focusing on the research and development, production and sales of composite manhole covers and products, and is a participant of the national standard GB/T23858-2009, and has obtained a number of system certifications such as ICMQ (Italy), UKAS (UK), ISO90001 and ISO140001. Jinmeng has an independent R & D centre and has independently developed composite materials with high strength, corrosion resistance, light specific gravity and high flexibility, and has obtained a number of invention and utility model patents.

What is composite material?

The composite material is a new type of material that is composed of several types of different materials, such as organic polymers, inorganic non-metals or metals, through a composite process. It can not only retain the main characteristics of the original composition material, and obtain the performance that the original composition does not have through the compound effect. The performance of each component can be complemented and related to each other through design, so as to obtain new superior performance, which is essentially different from the simple mixing of general materials.

As can be seen from the definition of composite materials, the essential difference between simple mixing of general materials and composite materials is mainly reflected in two aspects: 

First, composite materials not only retain the characteristics of the original constituent materials but also complement each other through the performance of each component And correlation can obtain new superior performance that the original component does not have.

The second is the designability of composite materials, such as structural composite materials not only can be designed according to the force requirements of the material in use but more importantly It can also carry out composite structure design, that is, the design of the proportion, distribution, arrangement and orientation of the reinforcement. Structural composite materials, it is composed of a reinforcement component that can bear the load and a matrix component that can connect the reinforcement as a whole and play a role in transmitting force.

SMC (sheet molding compound) is suitable for molding various parts from small to large, from flat plates to very complex shapes. Can provide the possibility of continuous stranding or matt SMC (sheet molding compound) has a variety of colors and usually can be color matching SMC (sheet molding compound) has excellent physical, heat-resistant, flame-retardant and chemical resistance.


Composite manhole cover material composition

  • The composite manhole cover belongs to the inorganic synthetic composite manhole cover, which is made of a new type of high-strength inorganic synthetic material and glass fiber composite. It is a medium-to-high grade manhole cover product. Resin fiberglass composite manhole cover is also called fiberglass manhole cover, plastic manhole cover. Non-metallic materials will not rust.

  • The inside of the composite manhole cover is reinforced by mesh steel bars, and the key force-bearing part is specially strengthened. When an inevitable external impact occurs, the pressure can be quickly dispersed to ensure the safety of people and vehicles. Shockproof.

  • The glass fiber material  can be composite reinforced materials such as resin and does not contain metal components. However, it has the same or even higher toughness and strength. After long-term use, the product will not be crushed or damaged, and it can completely prevent the occurrence of "urban black hole" accidents. And it is not conducive yet.

  • The weight of the composite manhole cover is much smaller than that of the cast iron manhole cover. It only contains reticulated steel bars inside, and the content is small, and because the manhole cover is extremely strong, it is difficult for thieves to damage the manhole cover to take out the few steel bars. Therefore, the composite manhole cover does not have much theft value. Due to the lightness of the composite material, the composite manhole cover is more convenient to use. It is easy to transport, install and repair. The labor intensity and cost of transportation, installation and construction are greatly reduced.

  • The composite manhole cover has high compressive, flexural, and impact-resistant strength, and has a long service life. durable. Through scientific formula, advanced technology and perfect technical equipment, the manhole cover enables the product to be used normally in the environment of -50℃~+300℃. And it has the advantages of corrosion resistance and can adapt to special corrosive environments.

  • High-cost performance, beautiful appearance. Patterns can be designed on the surface, and the colors are bright and diverse and adjustable. It can be equipped with a locking structure according to customer needs to realize the anti-theft of property in the well.

Why we choose composite materials to make manhole covers

  • The composite manhole cover has a zero scrap value, which eliminates the theft of the manhole cover.

  • Cast iron manholes and metal manhole covers are stolen every day. The thieves steal the cast iron manhole cover and let vehicles, people, or animals fall into the hole.

  • Composite manhole covers provide a quick, easy and affordable method to prevent manhole covers from being stolen. FRP manhole covers or composite manhole covers have no waste value.

  • The weight reduction of composite manhole covers means that the probability of worker injury is reduced. The composite manhole cover is lighter and easier to handle and place in practical engineering.

  • Cast iron manhole covers usually weigh between 100 and 200+ pounds. The weight reduction of composite manhole covers and glass fiber manhole covers can reach more than 60%.

  • We consider the convenience and safety of customers and pedestrians from all aspects of production, installation and use. Starting from the realization of all aspects of functional convenience, composite materials are the well-deserved first choice for manhole cover materials. Solve many functional and long-term problems of the manhole cover at one time.

Composite manhole covers are also ideal for special environments

The composite manhole cover can easily resist the corrosive environment. Sewers and sewage systems can be highly corrosive. Hydrogen sulfide is corrosive, toxic, heavier than air, flammable, and even explosive. When dissolved in water, it becomes a weak acid called hydrosulfuric acid or sulfurous acid. When heat and humidity are combined with a long retention time, ideal conditions for microbial induced corrosion are created. This corrosion can eventually damage most of the sewer infrastructure, but the composite manhole cover is not affected. Composite manhole covers and frames are ideal for corrosive settings found in municipal collection systems, sewers and industrial pretreatment applications.

Thanks to perfect qualification, excellent materials developed independently, strong technical team and technical strength, Jinmeng occupies a pivotal position in the composite manhole cover industry. Jinmeng's composite manhole covers are made by high temperature moulding process and are formed in one go. The products can reach the highest load-bearing grade F900, with a single point bearing pressure of 90 tons and a normal service life of more than 20 years.

The advantages of Jinmeng's composite manhole cover compared with other manhole cover:



The high-strength SMC manhole cover is moulded at high temperature and high pressure, and has excellent overall bending and tensile strength; during testing, it deforms slightly under high pressure as the pressure increases, and returns to its original state when the pressure is removed, and there are no cracks on the lower surface under pressure.



The structure of the product is scientifically designed, with uniform thickness and good integrity, and there are no particularly weak areas of stress. The product has high bending and tensile strength and is fatigue resistant when crushed several times.

Friction resistance

Friction resistance

A highly wear-resistant formula is used in Jinmeng SMC, and the wear resistance far exceeds the standard requirements.



Unlike cast iron that blocks electromagnetic waves, SMC has good wave-transmitting performance, and the communication signals in the well can be directly transmitted to the ground base station through the SMC manhole cover. SMC materials have been widely used in fields such as smart manhole covers and 5G radomes.



The product has good anti-static performance, which eliminates the potential safety hazards caused by static electricity, and has good insulation. It is widely used in gas stations and other oil gas industries.



‘Ultraviolet absorber’ is introduced in the product design, which effectively improves the anti-ultraviolet performance of the product; improves the anti-aging performance, prolongs the fading time of the product, and extends the service life of the product. 


Corrosion Resistance

FRP (organic glass fiber reinforced plastics ) itself is a world-recognized, good corrosion-resistant material; it has extremely high resistance to atmosphere, water, and general concentrations of acids, alkalis, salts, and a variety of oils and solvents; it has been universally applied to all aspects of chemical corrosion protection.

special locking system


1. The natural properties of SMC material make it have no recycling value, and prevent traffic accidents and road safety hazards caused by theft.

2. The simple and innovative anti-theft system design concept enables the manhole cover to be opened only by a specially designed key, which greatly improves the safety.



Compared with cast iron manhole covers and cement reinforced manhole covers, the weight is lighter. Easy for the construction and maintenance, while greatly reducing transportation costs.


Personalized customized service

Product structure / size / pattern / color / performance / carrying capacity / function / brand customization.

Excellent stability

Excellent stability

Jinmeng’s products use its own research and development of higher purity of the anti-shrinkage system, the general shrinkage rate of the product is only two thousandths, can achieve 0 shrinkage, far lower than the traditional cast iron material shrinkage. It makes the cover flatter, the deformation rate smaller, and the combination surface of the cover and the base flatter, effectively avoiding problems such as bouncing of the cover when the vehicle drives by, strange noises, and wear and tear caused by mutual friction between the cover and the seat.

It is not that the composite material manhole cover is not good, but not choose the right manufacturer and product. Please recognize Hangzhou Jinmeng Road Establishment Co., Ltd. 

*If you would like to have a question then get in touch today, we are ready to assist 24/7. We welcome your cooperation and we will develop with you.

 Factory-direct Connectivity Solutions.
 High quality, Competitive Price.
 Custom-tailored solutions.
 Problem-solving approach.
Jinmeng fabricates composite manhole covers, trench covers, Trench drain grates, customized composite valve boxes, manhole chambers.
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If you would like to have a question then get in touch today, we are ready to assist 24/7. We welcome your cooperation and we will develop with you.

 Factory-direct Connectivity Solutions.
 High quality, Competitive Price.
 Custom-tailored solutions.
 Problem-solving approach.