How to select Conveyor belts for pharma applications

Conveyor belt is an essential element of pharma equipment in their various departments. Primarily responsible for transferring items from one point to another, they assist humans in heavy items and at frequent frequency. 

What are conveyor belts?

Conveyor belts are mechanical structures that transport material from one point to another. The belt is the main part of the conveyor and performs the transfer function. 

Unlike other systems, the conveyor remains stationary during material transfer; instead, the belt rotates at its total length. The material to be transferred is placed on the belt, which then transfers it from one point (start of belt rotation) to another ( end of belt rotation). 

Conveyor belts are commonly used in the manufacturing industry, including the pharmaceutical industry, to transfer material from one machine or area to another machine or department. They can be manufactured in a variety of sizes and physical dimensions, making them suitable equipment for a variety of transfer applications. 

Components of Conveyor belts

There are multiple components in a conveyor belt that help convey its shape and perform its function. Some key components include, but are not limited to 

Motor—Motors are the main driver of the conveyor belt. They power the belt, which rotates as the motor  exerts force on the belt. The motor can have varying power specifications. Selection depends on the conveyor belt's load. The higher the load requirement, the higher the motor specifications. Commonly motor is control through electrical & electronics control, which control variety of functions, such as the motor's speed, start/stop and performance monitoring.

Pulley and Rollers—The motor does not directly operate the belt; instead, the pulley takes the force from the motor and then rotates the belt. It has several mechanical functions, such as adjusting the belt's tension. 

Rollers are deployed across the belt's length to support the belt and transferring material. They help maintain the belt's position on the conveyor to prevent slipping and de-shaping

The pulleys are strategically placed at various positions across the belt's length, and depending on the belt's length, there can be more than one pulley in a single belt.

Belt – a flexible material wound across the ends of the conveyor. Its material can be rubber, PVC, nylon or any other suitable. The items to be transferred are placed on the belt’s surface and rotates under the influence of motor. 

Frame—A frame is a mechanical structure that supports the entire conveyor belt and its parts. It is commonly made from steel, iron, or aluminum, depending on the area requirement in the pharmaceutical industry. Frames are also used to adjust the conveyor's height and length.

Control Mechanism—The control mechanism controls the conveyor's operation and activates its various functions, such as start / stop. Like other equipment, its operation is controlled through a central controller or PLC. 

There can also be an advanced control mechanism, that can control the conveyor's function depending on the physical items on the belt.

Why is it necessary to select an appropriate conveyor belt?

Let's discuss why it is necessary to select an appropriate conveyor belt.

In stable transfer

Material transfer in the pharmaceutical industry requires safe, reliable, and stable resources to prevent product damage. Additionally, the production environment is critical and must be free from all contaminants, foreign particles, and microorganisms.

If the conveyor belt is not selected, it will result in unstable material transfer. This could damage the product itself, alter physical attributes, and cause other problems. 

Shorten life span

A conveyor belt consists of many components that continuously move and require accurate product specifications for normal operation.

Failure to select an appropriate conveyor belt would exert excessive force and pressure on different moving part such as pulleys and belt. For example, if the belt’s capabilities are lower than the transferring items, it damages the belt's material or a pulley. 

Frequent wear and tear on the conveyor's part will shorten the machine's lifespan, resulting in more maintenance and less productivity.

Less productivity

Conveyor belts connect two different areas or machines, transferring material from the starting area or machine to the final location or machine. 

Inappropriate conveyor selection will fail in its entire purpose. As a result, there will be delays in material transferring, affecting the production of the whole area.

Belt damage

An essential aspect of all conveyor belts is the belt material. If it malfunctions, the entire transferring process will be disturbed.

An inappropriate conveyor selection will damage the conveyor, making it useless. Additionally, the damaged material can become a source of contamination in the area, reducing the belt's capacity. 

Some tips on selecting conveyor belts

Let's discuss some tips on selecting a conveyor belt for your pharma applications.

Available Space and length of the conveyor

Conveyor belt are used with one or more machines or areas. This limits the length of the conveyor belt directly proportional to the available area between the two machines or areas. Some conveyor belts are short, for example, when transferring product from the packaging machine to collect it for further processing. On the other hand, some conveyor belts are longer, such as in the secondary and tertiary packaging sections. 

Before selecting conveyor belt, know the available area for your conveyor belt. Determine the distance between two machines or regions for which the conveyor belt is required. 

Conveyor Design

There can be a variety of designs that best suit your pharma application when using a conveyor belt. Because, production operations are dynamic in nature, consists of variety of processes, design, intermediate components, and product requirements. The conveyor belt must be able to accommodate all these requirements without affecting the actual product and process parameters. 

There are different specific functionalities incorporated in a conveyor belt to fulfil particular production process requirements, such as 

· Roller bed for applications when heavy items are being transferred

· Modular belt conveyor

· Cleated conveyor belt- to carry items on an incline 

· Curve conveyor belt – where the direction of transfer needs to be changed

Belt Material

Different materials can be used to make the conveyor belt, and selecting a specific material depends on the items to be transferred. This helps to increase the belt's life and ensure satisfactory belt performance. 

When purchasing a conveyor belt, it is necessary to select a belt, that is capable of handling the desired load without damaging the belt, changing its physical characteristics. Additionally, the material f construction for belt must be strong enough to handle common sharp, strong and rough items used in the manufacturing processes. 

To select appropriate belt materials, it is helpful to consult the conveyor manufacturer or internal maintenance team. Some belt types include 

· Polyurethane, where the product comes in direct contact

· PVC, when a belt is required in packaging operations

Plastic interlocking belt, where a high level of sterility is required. If damaged, only the damaged part is replaced

· Stainless Steel - used in high temperature applications and for the prevention of particulates in clean rooms

loading capacity

Loading capacity is the ability of a conveyor belt to bear the transferred items' physical weight and/or dimensions. To handle heavy items, the mechanical frame is designed to handle such items, such as support rollers, to withstand the force of the items. On the other hand, if items are not bulky, no support rollers are installed. 

When selecting a conveyor belt, always determine your load requirements and communicate them effectively to the manufacturer. The belt manufacturer will make the conveyor suitable for heavy items and ensure that it will not damage or break during the transferring process.

Speed control mechanism

The speed of conveyor belt can also be adjusted, and at the same time, they are operated at fixed speed.  

Selecting a fixed or variable speed conveyor belt depends on the application requirement. For example, in a high-speed packaging process, the conveyor belt must operate at high speed to synchronize with the packaging process.  Similarly, slower speeds offer more stability during the transfer process.

Machine Interlocking

Interlocking involves linking the conveyor belt’s operation with the attached machine, such as a blister or filling machine. This enables the conveyor machine to only run when the interlinked equipment is running. The conveyor belt automatically shuts down when the attached equipment is stopped, such as in the case of a breakdown or material change over duration. It prevents conveyor belt idle operation, thereby saving energy costs and increasing conveyor belt life.

Interlinking is possible by a sensor or feature in the interlinking machine. The output of the sensor directly goes to the conveyor belt, that controls the belt’s operation. Some machine manufacturers ( from which interlinking is required) provide a feature or sensor to be used by the conveyor belt. Otherwise, conveyor belt manufacturers have to develop their own

When purchasing a conveyor belt, know your options and see whether you require such a feature. If you need this function, inform the belt manufacturer in advance because a thorough study is necessary to implement such a feature. Additionally, this feature also comes at an extra cost, so it is wise to consider your requirements before the final decision

About the Author:

Muhammad Asim Niazi has a vast experience of about 11 years in a Pharmaceutical company. During his tenure he worked in their different departments and had been part of many initiatives within the company. He now uses his experience and skill to write interested content for audiences at PharmaSources.com.