What makes a chain better than a belt or a roller, and vice versa? The answer to this is nothing. Belts or rollers are no better than chains. It all primarily depends on what product you’re trying to move and your specific requirements for your project. All three have pros and cons, making them more fitting for some applications and unfitting for others.
This comprehensive article examines the three different kinds of conveyor systems: belt, chain, and roller, along with their uses and applications and pros and cons. Finally, we will understand when each conveyor should be used and compare chain conveyor vs. belt conveyor and chain conveyor vs. roller conveyor.
Understanding Conveyor Systems
Conveyor systems are mechanical assemblies or devices that carry goods and materials with minimal effort. While you will come across many different types of conveyor systems, they typically consist of a frame that supports either a belt, chain, or rollers, upon which materials and goods move from one place to the next.
They may be motored by gravity, a motor, or manually. These material handling systems can be found in several different kinds to suit the various materials or products that need to be carried. Several factors should be considered while evaluating the different options of assembly conveyor systems.
In the present day, there are 3 options for moving pallets from one station to the next: chains, belts, or rollers. Each transporting medium has its pros and cons that engineers must take into consideration.
The applications and engineers' preferences together define the precise requirements. Still, other factors, such as orientation, placement, and part accumulation, play a role. Other key application considerations include payload dimensions like the fixture or pallet’s weight and product size. Finally, available floor space also plays a vital role, as does the operating environment. For instance, products assembled in clean rooms call for unique setups. Now, let’s look at these three types of conveyors.
Belt conveyors are material handling systems that incorporate continuous belts to carry material or products. The belt is extended between two end-pulleys in an endless loop. Either one or both ends have a roll beneath. The conveyor belt has the support of either a metal slider pan for lightweight objects where no friction is applied to the belt to cause drag or on rollers.
Motors that use either constant or variable speed reduction gears provide the power. The belt itself can be composed of various materials, which should match the conditions under which it will be operating. The most prevalent conveyor belting materials include plastic, rubber, metal, fabric, and leather.
Conveying heavy loads signifies a more robust and thicker construction of conveyor belting materials is needed. Belt conveyors are usually driven and can be operated at multiple speeds, depending on the throughput required. The conveyors can be inclined or used horizontally. Moreover, a belt conveyor can be troughed for large or bulk materials.
Advantages of Belt Conveyor System
Most companies opt for conveyor belts because of their cost-effectiveness. Belt conveyor systems are the easiest and cheapest conveyors you will come across. Apart from the noticeable financial gains they provide by boosting production speed, belts are cost-effective even when compared to other types of conveyor systems, primarily due to the PVC’s competitive pricing.
They even have production benefits and can have alterations in elevation. A rubber belt conveyor system has a comparatively soft top, making them excellent for producing products that call for gentle care.
The materials can be loaded from any place along the belt in a belt system. In addition, the continuous belt is super easy and convenient to clean, which is why belt systems are usually used in the packing and manicuring of food products.
Disadvantages of Belt Conveyor System
One of the primary disadvantages of using a belt conveyor system is that the same surface that makes it ideal for handling delicate items is not as effective when transporting heavier, bulkier, and more abrasive materials.
While it may work initially, the rubber will usually get damaged with time, sooner than it typically would when moving appropriate materials. Also, the simplicity of belt conveyors is one of its most significant drawbacks, indicating minimal features.
Apart from that, the belt can be tricky to clean and, in general, does not leave a very satisfying result. Sticky materials tend to get stuck on the belt and ultimately transfer to the pulleys, rolls, idlers, and the return side.
Chain conveyors use mechanical devices attached to a moving member, typically cables or chains. Sometimes, multiple chains are used to move pallets or hard-to-carry products and materials.
Chain conveyors are used for different purposes and have many varieties compared to other conveyors. A chain conveyor is typically used in situations that a belt conveyor cannot tackle due to airtightness, temperature, weight, degree of curve, setting environment, durability, etc. The primary types of chain conveyors include slat, flight, bucket, pipe, apron, etc.
Buckets or flat plates are attached to the chain for carrying multiple stuff. Chains are engaged to wheels, sprockets are fixed to the front and tail, and materials are carried when the chains move forward by spinning the sprockets and wheels.
Advantages of Chain Conveyor System
A chain conveyor is driven by a continuous chain and is mainly used to carry heavy loads. Typically, a chain conveyor is a double strand configuration with the load to be found on the chains. However, there are several strand configurations available.
Chain conveyors are relatively easy to install. They typically call for minor maintenance and integrate easily. They’re sometimes known as a pallet conveyor because of their extensive use in transporting steel or wood pallets. Moreover, several chain options allow for flexibility in environments and in applications.
Disadvantages of Chain Conveyor System
It's not like chain conveyors don’t have any drawbacks. For instance, chain conveyors are not used in food production sectors because they tend to get dirty very quickly. They have several tiny cracks and crevices that grime and dirt quickly get into. The chains can also result in problems for more fragile loads that require a gentler touch of a PVC belt.
Moreover, the chain must be effectively lubricated if you want to maximize its wear life. It is recommended to use a good lubricant that can extend the chain’s useful life and allow the operator to regulate the frequency, speed, and specific location. Besides, the weight of the chains might be a bit concerning, and the chain drives can be noisy.
A roller conveyor system uses parallel rollers mounted in frames to carry the product manually or by gravity. Key specifications include the axle center and roller diameter dimensions. They’re used mainly in materials handling applications like bagging handling, loading docks, or assembly lines.
The rollers aren’t powered and use gravity to move the product if inclined or manually if mounted horizontally. Depending on the available floor space and the application, they can be curved or straight.
Roller conveyors have a simplistic design, so many advancements have been made to enable them to keep up with the changing industry trends. A drive or live roller conveyor is the biggest innovation. Each roller is linked to a motor through a chain/belt/shaft to enhance controllability.
This balances the rate at which materials travel down the pathway. It also enables these conveyors to have limited use in reverse motion, from low to high elevation. They can also operate in bi-directional applications. The rollers can navigate material in either direction by changing the motor’s direction.
Advantages of Roller Conveyor System
Roller conveyors feature power-and-free designs where the least amount of surface friction allows for higher payload carrying and higher point loading capacity. They’re available with/without filler blocks located between the transport rollers to minimize the access of small fasteners.
You can also use powered rollers on assembly lines. Refrigerators, dishwashers, and other large household appliances are usually gathered on these conveyors. It is a conveyor that uses gravity to move the product at a declining angle.
Roller conveyor systems do not use any power source, meaning less cost, and are more environmentally friendly. Moreover, rollers are low-maintenance conveyor systems, and their modular design enables them to be used in various ways.
Disadvantages of Roller Conveyor System
When using a roller conveyor system, you may have to pay specific attention to the products being moved, as sometimes the products can get damaged when moved by gravity. Moreover, roller conveyors are generally more heavy and bulky.
Therefore, they're not as portable as the other conveyor systems, making this one of their biggest drawbacks. Finally, roller conveyors don’t have any control over conveyor speed.
When to Use Belt Conveyors
For more complicated solutions, you might want to use a belted conveyor. Belt conveyors are ideal for products that have uneven or abnormal weight distribution, bagged materials, varied surfaces and shapes, and smaller sizes.
The irregularity of such items requires the complete surface support of a belt conveyor. If you are transporting a product on a decline or an incline, belt conveyors provide you the needed friction via alterations in elevation.
You will have more significant control required for fragile products to maintain the separation necessary for safe and protected product transfer. High-speed barcoding processes call for a belt conveyor to keep the products stable as they pass through the scanner.
Moreover, belt conveyors give you the accuracy you need via consistent speed for tracking and gapping processes. Regardless of their shape or weight, all products will maintain a constant speed.
Typical Applications of Belt Conveyors
- Pacing lines for assembly
- Economical conveyance within pick modules
- Kitting and assembly
- High-speed transport
- Pusher sorters with slick top belt
- Inclining and declining conveyor
- Gapping conveyor to separate products before inline scales or scanners
When to Use Chain Conveyors
You might want to use a chain conveyor system in specialty applications when dealing with materials under harsh conditions or when the material can be allowed to fall via gaps in the conveying surface.
Chain conveyors are ideal for transporting heavy products from one place to another. It may be the most appropriate if you have to move products through high-temperature zones, such as through ovens. Other types of conveyors might not be that suitable for this.
It is the best option for the transportation of products in either indexing or continuous modes (i.e., the chain starts and stops every time to move a product to the chain’s end using a sensor). Lastly, a chain conveyor is perfect in scenarios where it is crucial to change the speed.
Typical Applications of Chain Conveyors
- Sewage treatment
- Food processing
- Coal mining
- Timber harvesting
When to Use Roller Conveyors
A roller conveyor is the pillar of conveyors. A roller conveyor is perfect for carrying items that have flat surfaces, spurs and curves, product merges, and 90° belt or chain transfers. You might want to use a roller conveyor when it is not required to maintain precise positioning and control of the product.
Besides, it is suitable when the constant flow is acceptable. It is vital to know that transfer speed will vary with product weight. Hence, applications with products of significant variations in weight mustn’t expect to get a fixed transfer speed.
Typical Applications of Roller Conveyors
- Spurs and curves
- Load transfer
- Long-distance transportation of products
- Pallet dispensing
- Return lines
- Product delivered back and forth to robotic stations
- Bulk receiving goods
- Load accumulation
Chain Conveyors vs. Belt Conveyors
Chain conveyors are far more durable and easier to install than belt conveyors. This makes it the most preferred option for heavyweight items. Still, they have a significant chance of causing damage.
Besides, as chain conveyors are composed of a series of interlocking chains, they are relatively easy to fix than their equivalents. This is because everything is engineered in one piece. However, if a particular fragment of the belt is damaged, the entire thing gets damaged.
Conversely, if a link on a chain gets ruined, it can be easily fixed as it is just an insignificant part of a larger system, making it unnecessary to dismantle the whole thing. Chains can be used in applications with fixed centers, where there is unlimited center distance, and the chain’s length is adjustable.
Proper tensioning is needed but not to the same accuracy as with belts. Unlike belts that need to be bought and stored in specific lengths for all applications, you can purchase a chain in bulk and cut it to length as required for various applications.
On the contrary, toothed and flat conveyor belts can carry pallets from one station to the next on the production line. Usually, this method of conveyance is used for applications that entail light payloads or small parts.
Products assembled in this manner include auto parts like spark plugs and wiper motors and small consumer items like razors. This indicates that belt conveyors' primary advantages are accuracy, speed, and cost.
Belts are also more inexpensive, accurate, and offer higher speeds than plastic chains. They also don't require any additional components.
A flat belt is the most cost-effective conveyor regarding the total cost of ownership over the conveyor’s life and the initial investment. While the startup cost of installing a belt is higher than a roller chain, the price per meter makes a belt conveyor system the most economical of all types of conveyors.
Chain Conveyors vs. Roller Conveyors
A roller conveyor offers the highest point loading and payload carrying capacity. Moreover, it is also fastener-free. A roller conveyor has no place for a fastener to become lodged, unlike chain conveyors. Furthermore, conveyor maintenance is one of the most critical factors often overlooked by manufacturing engineers.
A roller chain is one of the easiest conveyors to install, handle, and maintain. It is the most long-lasting and durable of the conveyor types. Roller conveyors are easy to lubricate, specifically when done with an automatic lubrication module. Due to the rollers having a low coefficient of friction, there is significantly low wear to the workpiece pallets.
Also, chain conveyors generally do not allow the products to accumulate or nest up against each other without pushing the product sideways across the chain or off the chain. So, if you require accumulation, then a roller conveyor seems like a more convenient option.
But, since roller conveyors are heavy and not so portable, chain conveyors can act as a better option. They can be used in lifting applications and conveyors using customizable, integral attachments to move the items.
While assessing the different kinds of conveyor options available, manufacturing and design engineers must always keep an open mind. This is because most people and companies are used to the old ways of doing things. But sometimes, a lack of willingness to learn something new and knowledge can be an obstacle.
Sometimes, engineers have a predetermined media in their minds, which is based on prior experience in several circumstances. Past history and personal preference are two of the most significant mistakes most engineers tend to make while choosing between rollers, belts, or chain conveyor systems.
The applications engineer is accountable for objectively observing the complete conveyor system in order to make the best recommendation or selection based on the application, the environment, the payload, and other factors.