A conveyor belt is a continuous moving surface that carries materials or products from one place to another. They are considered one of the most important inventions in modern industries. Today, you can find them everywhere, from airports and supermarkets to factories and mining sites. But have you ever wondered how conveyor belts are made?
Actually, making a conveyor belt is far from simple. Every industry requires conveyor belts tailored to meet its unique demands. That’s why manufacturers carefully design and prepare conveyor belts. If you are new to this topic, you are in the right place! This article will break down the entire process of how conveyor belts are made in easy steps. So, let’s get started!
Basic Structure of a Conveyor Belt
A conveyor belt is essentially built in layers, and each layer plays a distinct role. So, before we proceed to the manufacturing process, let’s first understand the basic structure of a conveyor belt.
- Karkasse: The carcass is the backbone of the conveyor belt. It is the inner layer that provides strength and shape. Depending on the type of belt, the carcass may be made of fabric or steel cords for extra strength. The carcass determines the strength and durability of the belt.
- Top Cover: The top cover is the outer layer of the belt. It directly touches the materials being carried. Since it faces the most wear and tear, it is made of strong materials like rubber, PVC, or polyurethane. Moreover, the thickness of the top cover depends on the purpose.
- Bottom Cover: The bottom cover is on the opposite side of the top cover. It comes into contact with the rollers or pulleys that cause the belt to move. Its job is to protect the carcass from wear caused by continuous contact with the moving parts. It is usually made of the same material as the top cover but may be thinner.
- Skim Coats: Between the carcass and the covers, there are thin layers of rubber. These layers are called skim coats. They act like glue, bonding the covers with the carcass. Without them, the belt could peel apart under stress.
- Additional Features: In some cases, belts are made with extra features. Those features are added to meet the industry’s needs. For example, some belts have sidewalls. They are raised edges to keep materials from falling off. However, some belts feature cleats. These are ridges or blocks on the surface to push materials uphill.
Manufacturing Process of Conveyor Belts: A Step-by-Step Guide
We have seen what conveyor belts are made of and how their layers are arranged. But turning raw material into a durable belt requires a well-planned manufacturing process. So, let’s drill down and explore how manufacturers bring all the parts together to create a working conveyor belt.
Step 1: Designing the Belt
The very first step in making a conveyor belt is designing it carefully. This stage is crucial because not every conveyor belt is used in the same way. As you know, a belt in a bakery must be light, smooth, and food-safe. However, a belt in a mining site must be robust and resistant to heavy loads and sharp materials. That is why manufacturers first study the purpose of the belt.
When designing, engineers think about what kind of material a belt will carry. Additionally, they evaluate the environmental conditions under which a belt will work. Based on these needs, they select the right materials available. Another part of designing is deciding the size and thickness of the belt. Manufacturers first understand the purpose of the belt and then determine the thickness.
Step 2: Preparing the Materials
After finalizing the design, the next step is to prepare the raw materials that will be used to make the belt. This step directly decides the quality of a conveyor belt. How? Actually, the quality of the belt depends on the quality of the material. So manufacturers carefully select rubber, fabric layers, steel cords, or plastics based on the design needs.
Each of these materials is first inspected to make sure it meets the quality standards. After that, they are usually blended with other materials for added safety. For example, rubber is mixed with special chemicals to enhance its flexibility and heat resistance. However, if the design requires steel, they are first coated to prevent rust.
Step 3: Building the Carcass
The carcass is the backbone of the conveyor belt. The purpose of the carcass is to carry the weight of the materials being transported. It provides strength and shape to the entire belt structure. Once the raw materials are prepared, manufacturers begin by carefully layering. This layering can be made from any material, such as fabric, plastic, or steel cords.
They place these layers in a specific order and direction to give the belt both flexibility and durability. However, the number of layers varies in each type of belt. For example, if the belt is being built for handling light weights, it will have fewer layers. However, heavy-duty belts incorporate a larger number of layers.
Step 4: Applying the Rubber Covers
Once the carcass is built, the next step is to add rubber covers on both the top and bottom sides. These covers act like a shield, protecting the inner structure of the belt from damage. During this step, manufacturers carefully place rubber sheets on the carcass. After that, they are pressed together using heat and pressure, allowing them to bond tightly.
However, the top cover is usually thicker. WHY? Because it directly faces the load and deals with friction, heat, or even sharp materials. The bottom cover is slightly thinner, but it still plays a vital role in protecting the carcass. But you should know that these covers are not added as they are. Instead, they are first formulated to match the environment where the belt will be used.
Step 5: Curing & Vulcanization
After adding the covers, the belts undergo a crucial process known as curing or vulcanization. This step is what gives the conveyor belt its final strength, flexibility, and durability. You can think of vulcanization as baking the belt under controlled temperature and pressure. HOW? Actually, during this process, the belt is placed in a large press or autoclave.
There, it is heated at specific temperatures for a set amount of time. The rubber goes through a chemical change. This change makes it tougher, more elastic, and resistant to wear and tear. Without vulcanization, the belt would be weak, soft, and prone to easy damage. By the end of the curing process, the belt achieves its final properties. It is ready to handle heavy loads and harsh conditions.
Step 6: Cooling & Finishing
After vulcanization, the belt is extremely hot because it was subjected to high temperatures. If it is taken out and used immediately, the rubber could deform or lose shape. That’s why the belt is allowed to cool down slowly. Some belts might cool down to room temperature after a few hours. However, in large factories, the belt passes through special cooling machines.
Those machines blow cold water or air over the belt to quickly lower the temperature. After cooling, the belt goes through a finishing stage. In this stage, extra materials, rough edges, or uneven surfaces are trimmed off. Manufacturers also carefully check for smoothness and even thickness across the entire length. If required, they do surface treatment for added protection.
Step 7: Testing & Quality Check
Once the conveyor belt is made, it cannot be used immediately. It must undergo strict testing and quality checks to ensure it works safely and reliably. This step is critical because conveyor belts are used in heavy industries. Hence, a minor defect could cause serious breakdowns or accidents. At this stage, engineers conduct various tests depending on the type of belt.
For example, the belt is checked for its strength and flexibility. They test to see if it can withstand the weight, pressure, and bending. For checking heat, oil, and flame resistance, special tests are carried out. In addition to performance tests, the belt undergoes a visual inspection. Experts inspect for surface defects, including bubbles, cuts, uneven thickness, or poor bonding.
Materials Used in Conveyor Belt Manufacturing
The strength, durability, and performance of a conveyor belt mainly rely on its materials. Since conveyor belts are used in so many different industries, they must be built with materials that suit the job. That’s why manufacturers use a wide range of materials to offer a diverse choice. Let’s dive in and explore some common materials used in the construction of a conveyor belt.
1- Rubber
Rubber is the most commonly used material in conveyor belts. It is flexible, durable, and provides good grip, which helps in moving items smoothly. Moreover, rubber belts are also resistant to wear and tear. This makes them suitable for industries that transport heavy or rough materials. But, depending on the need, manufacturers may choose either synthetic or natural rubber for conveyor belts.
2- Fabric (Textiles)
Fabrics such as cotton, nylon, or polyester are often added to conveyor belts. These fabrics serve as the skeleton of the belt, providing it with strength and shape. They also prevent the belt from stretching too much when carrying heavy loads. You can find fabric-reinforced conveyor belts in warehouses, airports, and factories.
3- Steel
For very heavy-duty work, such as mining or cement plants, belts must be extremely rigid and robust. For those industries, manufacturers often use steel cords or wires in the belts. Steel makes the belt extremely strong and capable of carrying tons of material without breaking. At the same time, steel cords allow the belt to bend around pulleys. As a result, a belt remains flexible while being strong.
4- PVC (Polyvinyl Chloride)
PVC is a type of plastic material often used in conveyor belts for light to medium applications. It is smooth, easy to clean, and resistant to chemicals. This makes it perfect for food, packaging, and pharmaceutical industries. Moreover, PVC belts are also lightweight. As a result, they run more smoothly, which reduces the stress on the drive motor and lowers energy use.
5- PU (Polyurethane)
Polyurethane is another plastic material used in the manufacture of belts. This material is known for its hygiene and flexibility. For example, they are non-toxic, resistant to oil and grease, and easy to sanitize. Hence, manufacturers use it to produce belts for bakeries, food processing plants, and the medical industry.
Häufig gestellte Fragen
How long does a conveyor belt usually last?
The lifespan of the conveyor belts typically depends on their frequency of use. On average, conveyor belts last for 3 to 10 years. Moreover, with regular care and timely repairs, it can last longer. However, without proper maintenance, it wears out more quickly.
How do conveyor belts improve efficiency?
Conveyor belts enhance efficiency by transporting materials more quickly than manual labor. Moreover, they reduce human effort and labor costs, allowing for continuous production. Conveyor belts also reduce mistakes and accidents due to their smooth movement.
Can conveyor belts be customized for special tasks?
Yes, conveyor belts can be designed and customized for many special tasks. For example, in the food industry, belts can be made from hygienic materials. However, in mining, belts are built stronger to carry heavy rocks. Some belts are heat-resistant, while others are designed to withstand freezing conditions.
Schlussfolgerung
Conveyor belts have become the backbone of several industries. They help carry several materials from one place to another. These belts may look simple from the outside. However, making them is a careful step-by-step process. Each industry needs a different type of belt. Therefore, manufacturers pay special attention to selecting the right materials for belts.
Among the various options, plastic, rubber, fabric, and steel are the primary materials used. This material variety enables manufacturers to meet the diverse needs of multiple industries. Moreover, each step, from design to completion, has its own importance. Lastly, checking the belt’s quality through various tests ensures the belt can perform its job without problems.