Conveyor belts have become a must-have for almost every industry. They help transport materials with ease. Right? In fact, some conveyor belts are so strong and durable that they are used in construction and mining sectors. The reason behind their excellent strength lies in the conveyor belt structure.
The conveyor belts are designed in a way that they consist of a few layers. These layers strengthen the core, so they provide reliable performance during operations. However, many seem to have no idea when it comes to the structure of conveyor belts. In this article, we will discuss everything about the structure of these belts. So, let’s begin!
Why Conveyor Belt Structure Matters?
In the previous article, we discussed the key components of conveyor belts. This article, however, focuses more on the design and structure of these belts. Strong structure is why conveyor belts are durable and perform well for a long time.
- The conveyor belt with a better structure offers balanced load distributions. As a result, the conveyor belt can handle more load. Handling higher loads is even more critical for belts designed for the mining and construction industries.
- The conveyor belt structure consists of three layers or covers. These layers or covers improve the strength of the core of conveyor belts. As a result, these belts can handle the harsh material with ease. They don’t wear out quickly, even when carrying the harshest materials.
- Remember, conveyor belts roll over the pulley. Right? If they are not flexible, they would break during rolling or moving over the pulley. The structure of these conveyors is designed to make the belts more flexible. They move around the rollers and pulleys without showing any sign of wear or breaking.
- The conveyor belt with an inefficient structure is more prone to slippage issues. The belt can slip out of the pulley. If this occurs, there will be additional downtime, which will impact conveyor belt efficiency. The conveyor belts are designed to prevent slipping, even when moving or operating at high speeds.
- Last but not least, a better-structured conveyor belt ensures a better lifespan, and vice versa. As I said, structure is responsible for making conveyors robust and resistant to wear. Remember, robust conveyor belts will last longer and withstand harsh usage easily. Conveyor belts with compromised structure are fragile and prone to damage.
Structure of Conveyor Belts
People generally believe that conveyor belts have single rubber layers. This layer moves and transports the material from one point to another. However, this is not true as the conveyor belts consist of complex structures. They have multiple layers and reinforcements that ensure the stability of these belts. Here is a list of those key layers:
- Top layer
- Carcass (core)
- Bottom layer – it rubs against the components like rollers or pulleys.
- Glue or Skim coat – keeps the structure of the whole conveyor belt firm and intact.
- Frame (Base – generally made of steel materials).
Apart from these layers, the conveyor belt structure also contains other components. These include fabric reinforcements, frames, and other components. In the section below, I will explain all the parts that make up the structure of conveyor belts.
1- Top Layer
The conveyor belt consists of three major layers. One layer that remains on the top plays a key role in protecting the other two layers, especially the carcass. This top layer generally remains in contact with the materials being transported. The layer of the conveyor belt is usually made of rubber materials. However, it has a higher thickness, which makes it robust and long-lasting.
It can resist cuts and other harsh usage, protecting the overall conveyor belts. Some manufacturers use natural rubber, while others use synthetic rubber in making this top layer. Have you ever noticed that some conveyor belts are heat-resistant while others are oil-resistant? They are made by using specific types of rubber in the top or outer layers.
There are some rubbers available that are heat-resistant. Manufacturers use heat-resistant rubber to make heat-resistant conveyor belts. On the other hand, resistant rubbers are used to make oil-resistant conveyor belts. The primary role of the top layer is to protect the carcass (the core of the belts) from cuts and harsh impacts. Without the top layers, the conveyor belts may not be as strong as they are with them.
2- Carcass (Core) with Fabrics Or Steel Reinforcement
The carcass or core is the most crucial part when it comes to the structure of the conveyor belts. This carcass is present between the top and bottom layers. In simple words, it remains sandwiched between two layers (top and bottom). Are you thinking about the composition of this carcass?
Generally, conveyor belts are made with fabric materials. This fabric is woven into layers and placed inside the middle portion. Different types of fabrics are used in carcasses, including polyester, cotton, and so on. These fabrics undergo weaving to enhance the core’s strength.
Some higher-end conveyor belts also come with steel material inside the carcass. These steel cables form a strong network within the carcass, ensuring durability. Without a carcass, the conveyor belt would be nothing but a sheet of rubber. It won’t have any rigidity or ability to carry the materials from one location to another.
Quick Highlight: The carcass (core) is so crucial that the top and bottom layers further protect it. The top layer prevents contact with the material that the belt carries. Similarly, the bottom layer of the conveyor belt ensures that the carcass does not rub against the pulley and remains in place. Remember, the safety of the carcass ensures the conveyor lasts longer and vice versa.
3- Bottom Layer
The bottom layer is responsible for the long-lasting performance of the conveyor belts. As I said, the conveyor belts consist of rollers and pulleys. The conveyor belts roll over these rollers and pulleys. Right? This bottom layer comes into contact when the belt rolls on the pulley. It rubs against the roller and pulley of the conveyor belts.
The consistent rubbing with conveyor belts can cause wear and tear. Therefore, this layer is made very strong using synthetic rubbers. Some manufacturers also add additives to increase flexibility and impart other desired properties. Remember, additives also make the bottom layer of the belt abrasion-resistant.
Due to this, this layer of the conveyor belt can withstand friction for a longer duration. The presence of the bottom layer ensures the carcass does not come directly in contact with the roller or pulley. If that happened, the carcass would get damaged by rubbing against the pulleys. In short, the bottom layer plays a crucial role in protecting and ensuring the overall safety of the conveyor belt.
4- Glue or Skim Coat (Layer)
Have you ever noticed how all the layers in the conveyor belt remain intact? That’s because of the skim coat. A skim coat is a thin layer that acts as a bonding glue. These bonding layers are present between the carcass and the other two layers (top and bottom). It ensures that the carcass remains firmly bonded to the top and bottom layers.
This skim coat is generally made of rubber materials, but it is very robust. Additionally, it exhibits excellent shock absorption properties. As you know, the core (carcass) of the conveyor belt faces stress during operation. Right? This skim coat acts as a shock absorber, absorbing some stress. In this way, it protects the carcass from extreme stress.
Additionally, conveyor belts run at some speed. If there is no skim coat or glue, the layers of the conveyor belt will separate from each other. The presence of a skim coat between the top, core, and bottom layers ensures that these layers remain bonded together. In simple terms, this glue or skim coat maintains the stability and integrity of the conveyor belt’s structure in the long run.
One of the key advantages of a skim coat is that it prevents contaminants and moisture from reaching the carcass. Remember, some conveyor belts are designed for use in moist conditions. They can carry liquid stuff. Spilling of this liquid can happen. In such a case, the skim coat ensures no moisture or liquid reaches the carcass. If this happens, the core or carcass will be severely affected.
5- Frame (Base)
The frame acts as the base for the conveyor belt. It holds all the parts and components of these conveyor systems. The frame of almost all conveyor belts is made of steel. Why? Because the frame undergoes stress and load when the conveyor belt is operational. So, it must be strong and rugged to withstand that stress.
In the previous article, I mentioned some parts that support the structure and functionality of the conveyor belts. Some of those supporting structures are as follows:
- Idlers
- Pulleys
- Axle bearings
- Drive unit (Motor & Gearbox)
All these parts are mounted on the frame of conveyor belts. It ensures that all parts of the belts are perfectly aligned for smooth operation. Idlers are parts that provide a base for the conveyor belts. Similarly, pulleys are the wheels that ensure that the belt moves smoothly. Similarly, the frame is the part that holds all the components of the conveyor belt together.
The frame of the conveyor belt makes up the overall structure of the conveyor. In simple words, the frame is the skeleton of the conveyor belt. It holds all the primary parts, including the belt itself. If the frame is weaker, the conveyor belt would be very fragile. It would be prone to damage, mainly when used in heavy-duty industries, i-e, mining or construction.
Manufacturers also use aluminum and stainless steel to make the frame of these belts. The material used to make frames affects the overall cost and price of conveyor belts. Generally, steel is used to make belts that are supposed to be used in heavy-duty industries. Aluminum frames are used in inexpensive conveyor belts, which are employed in less intense sectors.
Frequently Asked Questions
What is the structure of a belt conveyor?
The structure of the conveyor belts is based on three main layers. Those include the top layer, carcass (core), and bottom layers. The skim coat or glue acts as a bonding agent, keeping these layers intact and holding the conveyor belt structure together.
How to design a conveyor belt?
Different conveyor belts can have various designs and shapes. However, all of them have a conveyor belt consisting of three layers. These belts are supported by idlers and run by the pulley. The core (carcass) is the central part where manufacturers pay maximum attention.
Which material is used for conveyor belts?
The use of rubber (natural or synthetic) is a significant material used in conveyor belts. Apart from that, manufacturers use reinforcement of fabrics or steel in carcasses. These reinforcements make the carcass (core) extremely rugged and durable.
Conclusion
The use of conveyor belts is becoming more common day by day. This is due to the durability and performance they offer. Right? However, their durability is due to their unique structure, which sets the conveyor belt apart. The presence of three layers, including the carcass, is responsible for the ruggedness of these belts.
However, many people are unaware of the structure of conveyor belts. In this article, I’ve explained the complete structure and how these belts are designed. Remember, some conveyor belts are premium and come with carcasses reinforced with steel cable. However, most manufacturers use fabrics reinforced together in carcasses. The reason is that fabrics are inexpensive, which helps keep the price of conveyor belts low.