SMC/BMC Manhole Cover Mold/Mould
SMC/BMC manhole cover steel mold is key in producing FRP manhole covers. Its size, classification, and application advantages directly affect the quality and performance of the manhole cover. TechnoFRP has rich theoretical knowledge and production experience in the field of SMC/BMC compression moulding and can customize a complete set of SMC/BMC manhole cover production lines for you. If you have such requirements, contact us. Thank you.
1. SMC/BMC manhole cover mold structure
• Upper mold and lower mold: The mold usually consists of an upper mold and a lower mold. The interior of the upper and lower mold has the shape of the manhole cover, and a SMC manhole cover molding machine applies pressure to form the SMC material in the mold.
• Mold cavity and mold core: The mold contains a mold cavity (used to form the main shape of the manhole cover) and a mold core (used to form the surface details and structure of the manhole cover, such as textures, logos, etc.).
• Heating system: The mold is usually equipped with a heating system to heat the SMC material during the molding process so that it flows and solidifies at high temperatures.
• Exhaust system: To prevent bubbles or defects during molding, the mold design may include an exhaust channel to exhaust excess air or gas.
2. Size of SMC/BMC manhole cover mould
The size of the SMC manhole cover steel mold is closely related to the size of the manhole cover produced. The size design of the mold is usually based on the following factors:
• Diameter or side length of the manhole cover: The diameter of the common round manhole cover ranges from 400mm to 1200mm, and the side length of the square manhole cover ranges from 300mm to 1000mm. The mold size will be slightly larger than the actual size of the manhole cover to consider the material’s flow and shrinkage.
• Thickness of the manhole cover: The thickness of the manhole cover is usually between 25mm and 100mm. The mould design will consider this to ensure that the thickness of the manhole cover meets the requirements after molding.
• Mold wall thickness: To withstand the high pressure during the molding process, the wall thickness of the steel mold is generally between 20mm and 60mm, depending on the mold’s size and the shape’s complexity.
3. Manhole cover mold classification
SMC manhole cover steel molds can be classified according to different standards:
1) Classification by manhole cover shape:
• Circular mould: used to produce circular manhole covers, commonly used on municipal roads and sidewalks.
• Square mold: used to produce square manhole covers, suitable for use in industrial parks, residential areas, etc.
• Rectangular mold: used to produce rectangular manhole covers, suitable for use in special occasions such as drainage ditches.
2) Classification by mold structure:
• Single-cavity mold: only one cavity, suitable for producing single manhole covers, often used for small batch production.
• Multi-cavity mold: contains multiple cavities, can produce multiple manhole covers simultaneously, is suitable for mass production, and is more efficient.
3) Classification by surface texture:
• Smooth surface mold: produces manhole covers with smooth surfaces, usually used in applications requiring beautiful surfaces.
• Textured surface mold: the surface has an anti-slip texture or specific patterns, suitable for manhole covers requiring anti-slip functions or specific signs.
4. Usage process of SMC/BMC manhole cover mould
Material preparation: First, put the prefabricated SMC material into the mold.
Molding and pressurization: The mold is closed, and the hydraulic press applies high temperature and pressure. The SMC material flows in the mould and fills the mould cavity.
Curing and cooling: After the material is solidified at a high temperature, it is cooled and formed. The manhole cover is taken out after the mold is opened.
Post-processing: The manhole cover after molding may require some subsequent processing, such as removing edge burrs, surface coating, etc.
5. Typical applications
Urban roads and sidewalks: Manhole covers produced by SMC manhole cover steel moulds are often used in urban roads, squares, sidewalks, etc., providing high strength, anti-slip, anti-theft and other functions.
Industrial parks: In industrial parks, SMC manhole covers are widely used due to their corrosion resistance and insulation, especially for chemical plants, power plants and other occasions.
Residential and commercial areas: SMC manhole covers are often used in drainage systems in communities, shopping malls and other places, considering both beauty and practicality.
The diversity of sizes, detailed classification and multiple advantages of SMC manhole cover steel moulds in applications make them an indispensable tool in modern municipal, industrial and environmental protection projects.
6. More details about our SMC/BMC manhole cover mold
| Number | Specific matters | Detailed description |
| 1 | Selection of mold steel | Mold steel materials include: 45#, 50#, P20, H13, 718, 2738, NAK80, S136, SKD61, etc.This type of product has high requirements for appearance. The product surface requires high brightness, so choosing mould material is very important. However, considering the price, it is generally more appropriate to choose P20 steel. P20 is pre-hardened steel unsuitable for heat treatment but can be nitrided. Hardness 280HRC~400. Since it has been pre-hardened, mechanical cutting is not too difficult. Moreover, the hardness of this steel is higher than that of medium carbon steel, and the deformation is more stable than that of medium carbon steel, so it is widely used in plastic moulds. |
| 2 | Mould Base | LKM,HASCO,etc |
| 3 | Design Software | UG, PROE,CAD，CAXA |
| 4 | Design of mold structure | Professional designers design a reasonable structure to achieve the shortest production cycle, reduce unnecessary processing procedures in the later stage, and improve production efficiency. Cold runner, hot runner, and hot nozzle cold runner structures are the three most commonly used. |
| 5 | Cooling water system and gate design | Reasonable gate forms are designed according to the product’s structural characteristics and appearance requirements. There are large gates, latent gates, fan gates, needle valve gates, etc. A reasonable cooling system can make the mould temperature reach equilibrium quickly to improve product accuracy and production efficiency. |
| 6 | Parts configuration | Inserts, guide pillars, guide sleeves, sliders, slider sleeves, inclined ejector blocks, etc., are made of wear-resistant standard parts to increase the service life of the mould. |
| 7 | Cavity type | Single/Double/Multi-type |
| 8 | Mold surface treatment | Industrial polishing grade |
| 9 | Product demolding time | 6-90 seconds |
| 10 | Target mold life | More than 500,000 times |
| 11 | Time required to complete the mold | 25-70 days |
7. Precautions for mould use
1) Check that there is no debris in the mold cavity and core.
2) Check that the mold ejection mechanical system is operating normally.
3) Check that no debris is blocking the mold gate and the cooling system is normal.
4) Check whether the mold safety side lock is open, etc.
5) Required mold maintenance matters:
After the mold is used, clean the cavity and core. No debris should be left to avoid damaging the mold surface. Spray rust inhibitor.
There should be no cooling water left in the mold cooling system. It must be cleaned to avoid rust blocking the water channel.
The mechanical standard parts of the mold should be coated with lubricating oil, such as: guide pin-ejector pin-reset rod-lower guide pin, etc.
After the mold is closed, cover it with a dustproof cloth to prevent dust from entering the mold and causing it to rust.
8. Why choose us
1）The company has introduced more than ten advanced mold processing and testing equipment, such as precision CNC machining centers, CNC EDM machines, CNC deep hole drills, etc., from home and abroad.
2) High mould precision: TechnoFRP has experienced mold-making masters, professional technology, and strict control at every level.
3）Long mold life: The mold made of steel with a hardness of 20-56 can be pressed 100,000-1 million times.
4）Professional customization: Focusing on mold processing and customization for over 20 years. Different molds can be produced according to customer needs.
5）The company has a professional production workshop with an annual production capacity of more than 200 sets of large and small molds. It has 630-2000 tons of hydraulic presses to meet the needs of mold testing and molding processing.
