On a packaging machine, the drive system is rarely the first element that comes to mind. Yet behind a conveyor, a screw-capping system, a pump, or a labeling mechanism, different types of motors can be used to drive the machine’s movements.
Induction, brushless, and stepper motors do not operate in the same way and do not meet the same requirements. They also differ in terms of cost, whether for purchase, control, integration, energy consumption, or maintenance.
However, it would be too simplistic to try to determine which motor is “the best” or simply “the cheapest.” The choice depends primarily on the movement to be performed, the required level of precision, production constraints, and the overall design of the machine. Understanding the main differences helps ensure that the right questions are asked when planning an automation project.
Why is the drive system important on a packaging machine?
A packaging machine must perform repetitive and coordinated movements: moving containers, positioning a product, driving a screw-capping system, applying a label, or actuating various mechanisms.
The drive system must be capable of performing these movements with the required characteristics:
- speed;
- movement precision;
- repeatability;
- torque;
- position control;
- consistent operation;
- adaptation to the production cycle;
- investment and operating costs appropriate to the requirements.
However, the motor is only one element of a complete system. Its operation also depends on the associated mechanics, control system, sensors, and control software. Its cost should therefore not be considered in isolation: the required variable-frequency drive or driver, position measurement systems, automation equipment, and integration time can also influence the overall cost of the solution.
This is why the motor type should never be evaluated independently of the function it needs to perform.
The induction motor: a proven solution for many types of movement
The induction motor, also known as an asynchronous motor, is a technology widely used in industry. On a packaging machine, this technology can be used in particular for movements requiring robust, continuous operation.
Induction motors are particularly valued for:
- their robust design;
- their reliability;
- their simplicity;
- their widespread use on production equipment;
- their generally controlled cost in applications that do not require highly precise positioning.
From an economic standpoint, an induction motor is often an attractive solution when the application primarily requires equipment to run at a constant speed or with relatively simple speed variations.
Its purchase cost may be lower than that of a comparable brushless solution. However, the complete system must be taken into account. Adding a variable-frequency drive, for example, increases the equipment cost but provides improved speed control.
When significant positioning or synchronization requirements arise, additional control and measurement systems may also reduce the initial economic advantage of this technology.
The brushless motor: precision and dynamic control
A brushless motor operates according to a different principle. As its name suggests, it does not have the mechanical brushes used in a conventional DC motor.
This more electronics-based architecture makes it possible, in particular, to achieve precise motion control and good dynamic performance. On a packaging machine, a brushless motor can be useful when the movement requires precise control of speed, torque, or position.
It can therefore be suitable for applications in which speed and precision are important.
Its key characteristics include:
- good control precision;
- strong dynamic response;
- no brushes to replace;
- good energy efficiency depending on the application;
- the ability to manage speed variations.
In return, a brushless drive system generally represents a higher initial investment than a simple induction motor system. The motor requires suitable control electronics and may be combined with a position feedback system to provide highly precise control.
This cost difference may nevertheless be justified when precision, dynamics, or torque control provide a genuine process advantage. The additional cost of the technology therefore needs to be compared with the benefit it brings to the operation and performance of the machine.
For example, our VS 600 is also equipped with a brushless motor for its screw-capping system. This choice of motor technology is directly related to the need to control the closing movement of the containers.
The stepper motor: precise control of movements
The stepper motor operates according to a different principle from the previous two technologies. It converts incoming electrical pulses into successive movements. The motor can therefore advance in “steps,” allowing its movement to be controlled precisely in certain applications.
This technology is particularly useful when movement must be sequential and repetitive.
Stepper motors are particularly valued for:
- their ability to perform precise movements;
- their straightforward control in certain applications;
- their good repeatability;
- their ability to operate at low speed with suitable control.
In terms of cost, a stepper motor can represent an attractive compromise for certain positioning movements. In a simple configuration, it can provide precise control without requiring a position feedback system as sophisticated as those used with some brushless solutions.
However, this advantage depends heavily on the application. When speed, torque, or monitoring requirements increase, additional systems may be required. A stepper motor operating in closed-loop mode, for example, requires position feedback and suitable electronics, which increases the cost of the system.
It can be particularly relevant for certain labeling or positioning mechanisms. As with the other technologies, however, its suitability depends on the movement concerned and the design of the machine.
What are the cost differences between induction, brushless, and stepper motors?
In general, a simple induction motor system is among the most economical solutions when continuous and relatively simple movement is required.
A stepper motor can also be economically attractive when it provides a straightforward way of performing a repetitive positioning movement. Its cost can, however, increase when the application requires more power, higher speed, or closed-loop control.
A brushless system generally requires a higher initial investment because of the motor, its control electronics, and the equipment required to control it.
Therefore, the technology that is cheapest to purchase is not necessarily the one with the lowest cost over the machine’s entire service life.
How do you choose the right drive system for your project?
When a company invests in a packaging machine, it does not need to select the motor type itself. However, several questions can be useful when evaluating the project.
What level of precision is required?
Some movements mainly require consistency, while others require more precise control of position or speed.
What dynamic performance is required?
Cycle speed can influence the choice of technology.
What are the constraints associated with the product and container?
The motor must be integrated into mechanics suited to the process.
What level of investment is appropriate for the requirement?
A more sophisticated drive system can result in higher costs without necessarily providing a benefit for a simple application. Conversely, attempting to reduce the cost of the drive system can be counterproductive if this limits the performance, precision, or reliability required by the process.
What will the operating cost of the solution be?
Energy consumption, maintenance, replacement parts, and any potential downtime are also part of the economic equation.
How will the machine need to evolve?
Future automation or integration into a line can also be taken into account during the design stage.
Drive systems and packaging automation
Motor selection becomes particularly important when several operations are automated.
In a complete packaging line, the different stations must operate in synchronization: filling, capping or screw-capping, labeling, and, where applicable, other operations.
The same applies to our packaging monoblocks, which combine several operations within a single piece of equipment.
The objective is therefore not to systematically choose the most sophisticated or cheapest motor, but to design an architecture that is consistent with the movements to be performed and the overall economics of the machine.
Induction, brushless, or stepper motors: none of these technologies is inherently better than the others for every application.
The induction motor is valued for its robustness and can meet a wide range of drive requirements, with a particularly attractive cost for certain simple applications. Brushless technology offers particularly effective dynamic control for certain movements, although it generally requires a higher investment. A stepper motor can perform precise, repetitive movements and may represent an economically relevant solution for certain positioning functions.
On a packaging machine, the choice therefore depends primarily on the function to be performed, the required level of control, the overall equipment design, and the relationship between the cost of the solution and the performance actually required.
At CDA, we incorporate this consideration directly into the design of our machines. Motor selection forms part of an overall approach combining mechanics, automation, electronics, and the constraints associated with the product and container, together with the search for the best technical and economic compromise.
Do you have a filling project, screw-capping, or labeling project and want to understand which motor technology is suitable? Contact our experts to evaluate the packaging solution that best matches your technical and economic constraints.
FAQ: Drive systems for packaging machines
What is the difference between an induction motor and a brushless motor?
An induction motor operates using a rotating magnetic field, whereas a brushless motor relies on electronic commutation. Brushless technology can provide precise and dynamic motion control in applications that require it.
Why use a brushless motor on a packaging machine?
A brushless motor can be beneficial when an application requires precise control of speed, torque, or movement. Its generally higher cost compared with a simple induction motor system should therefore be considered in relation to the required performance.
What is a stepper motor used for?
A stepper motor can perform successive, repetitive, and precisely controlled movements. It can be suited to certain mechanisms that require repetitive movements and precise positioning.
Which motor is the cheapest?
There is no single answer because the cost depends on power, the control system, and the required performance. For simple movements, an induction motor is generally an economical solution. A stepper motor can be attractive for certain positioning functions, while a brushless solution generally represents a higher initial investment in return for more advanced control capabilities.
Should you only compare motor prices?
No. The price of the motor represents only part of the drive system cost. The variable-frequency drive or driver, any sensors and encoders, automation, integration, energy consumption, and maintenance requirements must also be taken into account.
Does an induction motor offer lower performance than a brushless motor?
The two technologies meet different requirements. The choice depends mainly on the function to be performed and the characteristics required for the movement. A more expensive or sophisticated drive system does not necessarily provide any benefit when an application does not require its additional capabilities.
Does the motor affect the precision of a packaging machine?
The drive system can contribute to movement precision, but it is not the only factor. Mechanics, transmissions, sensors, automation, and settings also play an important role.
How do you choose the motor for a packaging machine?
The choice is generally based on the function of the movement, the required level of precision and control, speed, torque, and the overall design of the machine. The overall cost of the solution, including investment, integration, energy, and maintenance, must also be taken into account.
