Everything You Need to Know About Conveyor Belt Splicing

Conveyor belt splicing is a strategic process to ensure the reliability, safety and productivity of conveyor systems. Choosing the right splicing method means anticipating the site's mechanical, environmental and operational constraints. This guide will tell you everything you need to know about the different splicing methods, their procedure and key benefits in different industrial contexts.

WHAT IS CONVEYOR BELT SPLICING?

Conveyor belt splicing is the process of joining the two ends of a conveyor belt to create a closed loop, allowing for the continuous flow of materials. This operation can be performed in two main settings:

In the workshop, during the manufacturing or preparation of the belt,
On-site, during installation, repair or replacement.

The choice of splicing method depends on several factors including:

The type of belt (textile, metal, PU, PVC, rubber, etc.)
Operating conditions (abrasion, humidity, temperature, exposure tochemicals)
The tension of the belt
Accessibility of the conveyor
Acceptable downtime for the operation

These considerations ensure that the splicing process is effective and suitable for the specific application.

CONVEYOR BELT SPLICING METHODS

There are several methods for splicing a conveyor belt. Two of the most common techniques are mechanical splicing and vulcanization. Let’s explore the specificities and main advantages of each method!

MECHANICAL SPLICING

Mechanical conveyor belt splicing is a practical and versatile method that involves joining conveyor belts using metal hinges or plates, which are secured with a mechanical fastening system. This technique is quick to implement and suitable for all types of belts, regardless of their width, thickness, length, speed, or tension. It can be executed in almost any environment, regardless of temperature, moisture or the presence of residue.

This method is particularly beneficial in heavy-duty industries such as mining and quarrying, where belts often experience significant wear and tear. It is also useful in situations where belts need to be frequently expanded or replaced. Furthermore, mechanical splicing minimizes belt waste and is effective for both new and used belts.

VULCANIZATION

Conveyor belt vulcanizing uses heat (hot vulcanization) or chemicals (cold vulcanization) and pressure to create a seamless and durable bond between two pieces of a conveyor belt utilizing a vulcanizing press. This method requires specialized tools, skilled expertise and controlled conditions, including a clean environment with regulated temperature and moisture levels.

Vulcanization method	Process	Use	Pros	Cons
Hot vulcanization	Use of heat, pressure and curing time with a vulcanizing press	High-tension rubber or textile belts	Highly resistant joint, no extra thickness, excellent abrasion resistance	Requires heavy equipment, skilled personnel and longer downtime
Cold vulcanization	The ends are boded with a two-component adhesive	Moderate-tension belts, on-site interventions	Easier to carry out, no vulcanizing press required	Less durable than hot vulcanization, sensitive to humidity and ambient temperature

Although it involves more time and preparation than mechanical splicing, conveyor belt vulcanization is particularly effective for specific belt types and environments where long-lasting performance is essential

SCREW SPLICING

Screw splicing is a hybrid method between mechanical splicing and vulcanization. This technique is easy to perform and offers excellent resistance to tension, impact, and abrasion, ensuring reliable performance even in harsh operating conditions. The installation is quick and provides high mechanical strength along with excellent sealing, even for fine or dusty materials. It is compatible with abrasive or damp environments and is particularly well-suited for conveyors that experience impact or handle sharp products. Screw splicing is commonly used in quarries, mines, recycling centers, and cement plants.

MLT is the inventor and 1st manufacturer in the world to have designed and manufactured this splicing solution with the SUPER-SCREW®. This patented innovation has completely redefined splicing standards. Crafted from high-resistance rubber and reinforced with seamlessly integrated screws and washers, MLT’s SUPER-SCREW® offers exceptional wear and impact resistance, as well as 100% compatibility with scrapers. It is quick and easy to install, making it the ideal choice for fast and reliable repairs with minimal disruption to operations.

HOW TO DO CONVEYOR BELT SPLICING?

Splicing conveyor belts is a detailed process that demands precision and the proper tools. The specific steps, equipment and time required can vary based on the method chosen. Below is a general overview of how to splice your conveyor belts using either the mechanical or hot vulcanization approach.

CONVEYOR BELT SPLICING PROCEDURE

STEP 1: PREPARING THE BELT ENDS

Cutting

For a mechanical joint using fasteners, the cut must be straight and perpendicular to the belt axis.
For a vulcanized or screwed rubber joint, an angled cut is recommended to increase the contact surface and improve the mechanical strength of the splice.

Degumming / depolishing

On rubber belts, remove the top cover using a sander or stripper to expose any textile or metal reinforcement.

Cleaning

Clean the surface with specific solvents to remove dust, oils, and rubber residues.

Marking

Finally, trace alignment marks on both ends to ensure a perfectly symmetrical splice and avoid any offset during operation.

STEP 2: ALIGNMENT AND POSITIONING

Longitudinal alignment

Both ends must be perfectly aligned along the belt axis.

Use of patterns

For mechanical fastening, use patterns to ensure the precise positioning of the splicing elements.

Temporary fastening

Use clamps hold the ends in position throughout the operation.

STEP 3: APPLYING THE SPLICING METHOD

Mechanical splicing

1. Insert the fasteners using an installation tool (manual, pneumatic or hydraulic)

2. Check that the fasteners are properly engaged.

3. Close the splice with a connecting rod (made of steel or stainless steel, either coated or uncoated).

Hot vulcanization

1. Apply the primer and bonding adhesive

2. Position the belt in a vulcanizing press

3. Set the temperature, pressure and time

4 .Ensure controlled cooling to avoid internal stresses

Cold vulcanization

1. Apply the two-component adhesive to the prepared surfaces

2. Manually assemble the ends using a roller or light press while applying consistent pressure

3. Allow it to dry for 12 to 24 hours, depending on the ambient temperature

Screw splicing

1. Position the Super-Screw®

2. Screw the Super-Screw® splice using a torque-controlled screwdriver

3. Check for tightness and uniformity

STEP 4: POST-SPLICING QUALITY CONTROL

1. Visual inspection: Check for alignment, flatness, and the absence of bubbles or detachment.

2. Tension control: Adjust belt tension according to the manufacturer's recommendations.

3. Functional test: Start up with no load, then apply a progressive load and observe the splice’s behavior for noise, vibration, or any possible offset.

DIFFERENT BELT SPLICING TOOLS

Mechanical splicing typically requires basic tools like hammers or an installation tool, along with the appropriate fasteners.

Vulcanization, on the other hand, demands more advanced equipment, specifically a vulcanizing press. These presses can be either electric or hydraulic:

Electric vulcanizing presses re faster, more energy-efficient, and provide a practical solution for many splicing needs.
Hydraulic vulcanizing presses, deliver high pressure and heat, making them ideal for thicker belts. However, they require a hydraulic power source and tend to be more expensive.

Preparing a belt for splicing may also involve additional tools:

Splicing method	Tools needed
Mechanical splicing	• Industrial cutter or band shears: for clean end trimming. • Scribing square: to ensure a perpendicular cut. • Drilling jig (if required). • Manual or pneumatic installation tool : for inserting fasteners. • Rivet hammer or pneumatic gun: for rivet fasteners. • Connecting pin: to close the joint.
Hot vulcanization	• Rotary sander or belt grinder: to remove the top covers. • Cleaning solvents: to degrease the surfaces. • Metal ruler and compass: to trace bias lines. • Vulcanizing press (flat or angled): with heating platens, pressure system (hydraulic or pneumatic) and temperature control. • Thermal probe: to control curing temperature. • Programmable timer: to respect heating and cooling times. • Electric generator (for on-site operation without power supply).
Cold vulcanization	• Glue + hardener. • Metal spatula: to apply the glue evenly. • Roller press or light press: to ensure good contact during drying. • Precision balance: to measure out adhesive components. • Ambient thermometer: to check that conditions are compatible with gluing.
Screw splicing	• Electric stripper: to remove the belt’s top cover before splicing it. • Adjustable-torque electric screwdriver: to fasten the screws.

All methods will also require personal protective equipment (cut-resistant gloves, goggles, helmet, safety shoes), as well as a tape measure and spirit level for measurements and alignment.

HOW LONG DOES IT TAKE TO SPLICE A CONVEYOR BELT?

Mechanical splicing is a quicker method of joining materials, typically taking just a few minutes to complete. This makes it ideal for urgent repairs or installations in situations where minimizing downtime is critical. In contrast, vulcanization is a much longer process that can take several hours, depending on the size and type of the belt. This process involves heating, pressing, and cooling phases.

ADVANTAGES OF SPLICING A CONVEYOR BELT

VERSATILITY ACROSS APPLICATIONS

Conveyor belt splicing can be tailored to meet the diverse needs of different industries. Whether working with light-duty belts in the food sector or heavy-duty belts in mining, there is a suitable splicing method for each application. Mechanical splicing is best for environments that experience high moisture, dirt, or have limited space, while vulcanization provides dependable performance in cleaner, more controlled settings.

REDUCED DOWNTIME

Mechanical splicing can be completed quickly with minimal preparation, making it ideal for urgent repairs that minimize operational downtime. While vulcanization is more time-intensive, it ensures a durable splice that reduces the frequency of future disruptions.

Conveyor belt splicing is crucial for ensuring the efficient and reliable operation of conveyor systems. By understanding the key aspects of splicing, you can make informed decisions that minimize downtime, reduce costs, and maximize efficiency. You have the option to choose between mechanical splicing, known for its speed and versatility, and vulcanization, which offers durability and a seamless finish. Both techniques can significantly enhance the performance and lifespan of your conveyor belt.

With over 70 years of experience in providing conveyor belt solutions, MLT offers a wide range of splicing options, suitable for both light-duty and heavy-duty belts. We also provide vulcanizing presses for rubber and PVC/PU belts.

If you have any questions or need further information, please don't hesitate to reach out to our technical team!

SUPER‑SCREW®* 2024