Technical article
How Servo Technology Exceeds Highest Demands
Small impurities, big disaster. In the production of pharmaceutical primary packaging or medical plastic parts such as highly precise Luer-Lock systems, cleanliness for the machine, tool, and molded part is not just a formality, but a strictly regulated production standard, compliance with which determines the success or failure of entire batches. No one wants to have thousands of parts produced in vain - because of contamination on the screw cap. Servo-electric automation concepts not only perform translational and linear movements reliably, but also minimize contamination risks. But what technology is exactly behind this? Let's take a closer look at the servo advantages under the microscope.
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The optimal solution for the highest cleanroom classes
Where the highest cleanliness is essential, not a single drop of oil should ruin all the hard work. Injection molding tools and machines that operate with hydraulic solutions, however, reach their limits in cleanrooms. Only with considerable additional effort and comprehensive measures such as enclosing the hydraulic blocks or using special FDA or NSF approved lubricants and hydraulic oils can the risks of contamination be reduced - isn't there an easier way to do this?
In the field of injection molding machines for cleanroom applications, the trend has been clearly moving towards the use of all-electric machines for several years now - but hydraulic drives in injection molding tools can also be completely replaced by suitable servo system solutions. Servo motors operate as brushless and fanless motors, completely clean, energy-efficient with minimal heat loss, and without particle emissions. The low-lubricant technology is therefore ideal for cleanroom environments up to cleanroom class ISO7 / GMP-C / 10,000. No oil, hardly any particles, and on top of that, a space-saving design.
The significant reduction, up to the complete elimination, of lubricants in injection molding tools also contributes to reducing contamination risks - however, movements must be carried out with higher precision and controllability - this aspect can also be easily achieved with servo motors.
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The company Wild & Küpfer relies on Servomold for cleanroom production.
Where high quality is required, strengths are revealed.
In addition to contamination-free conditions, outstanding precision and manufacturing quality are also key features of cleanroom production. The basis for this is provided by systems that allow manufacturing processes and tool movements to be aligned and repeated in high detail.
An important aspect is, for example, the required absence of burrs in plastic parts that will come into contact with blood later on - for instance, injection molds for Luer-Lock systems must be manufactured with very tight tolerances and narrow gap dimensions. In combination with the required absence of lubricants and highly dynamic movements for short cycle times, a situation arises that is difficult to control with the limited adjustable hydraulic systems.
Servo drives can be controlled sensitively and precisely by the position encoder built into the servo motor, such as an electromagnetic resolver or optoelectronic absolute encoder. Depending on the system, one revolution of the motor shaft of a servo motor is resolved into hundreds to thousands of increments (pulses) - the servo controller built into the servo drive uses these signals to control the servo motor with an accuracy of a few arcminutes precisely. This allows mechanisms to be positioned accurately to within 1/100th of a millimeter without the need to use an end stop. Torque, forces, and speeds can be limited and continuously monitored, and any type of acceleration can be realized. As a result, servo technology reduces mechanical stresses, significantly reduces the risk of damage, and increases the lifespan of the injection molding tool.
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Medical components with Luer-Lock thread - Servomold unscrewing unit unscrews precisely, quickly, and free from contamination.
Proven quality and stable processes
Without the appropriate servo control, a servo motor does not move a millimeter - this requirement is at the same time the greatest strength of servo technology. Modern servo controls not only provide full control of movements, but also enable the capture of relevant process parameters, thus contributing to the continuous monitoring of product quality.
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Analyzing the torque and temperature of the servo motor allows for direct conclusions about the consistency of motion sequences and provides important indications in case of process deviations. Changes or wear on the injection molding tool can be detected early, enabling targeted measures to be taken.
But also changes in the injection molding process due to material or parameter variations become apparent - for example, different injection pressures are reflected in the changes in demolding forces. Here, the process monitoring of the servo control offers ideal opportunities to ensure stable and verifiable processes.
Having an ace up one's sleeve with servo technology
Energy prices are at a record high, production facilities are under pressure, and there seems to be no end in sight. However, when it comes to energy efficiency, servo technology is outperforming all competitors. Compared to hydraulic systems, servo technology consumes 4 times less energy, and it even surpasses pneumatically-driven systems with a 10-fold reduction in consumption. How can servo-electric technology save so much energy?
The answer lies in the uncomplicated directness of servo motors. They immediately convert electrical energy into a rotational movement and therefore consume only as much power as needed at the time of movement. This is a clear advantage over hydraulic drives, where an electric motor drives a pump that generates the necessary oil pressure in the system. This oil pressure must be maintained permanently in a fully hydraulic system - in pneumatic systems, in addition to air pressure, line losses must also be constantly compensated for.
Does servo technology fit into your cleanroom?
Many advantages, but is the investment also worthwhile in the long term? The calculation should always be made with the future in mind. Investing in a servo-driven system always means investing in more control, insight, and foresight. The servo controllers used to control servo motors capture all operating parameters, enabling not only targeted control but also long-term process optimization and preventive maintenance. These transparent processes form the basis of the contamination-free production hall of tomorrow, where success is not left to chance but to precision.