Compact and Contamination Free: A Hygienic Line of Servo Actuators

December 15, 2022 by Seth Price

Mechanical devices can harbor environments that encourage the growth of bacteria, which is why designing hygienic equipment is crucial for sterile production lines. Enter WITTENSTEIN's newest servo actuators.

WITTENSTEIN alpha's latest line of servo actuators are now available and suitable for use in sterile environments. The axenia value servo actuators are designed specifically to prevent the growth of bacteria and fungi, reducing potential contamination in food, pharmaceuticals, and other sensitive products. 


WITTENSTEIN alpha's axenia value series of hygienic servo actuators

WITTENSTEIN alpha’s axenia value series of hygienic servo actuators. Image used courtesy of WITTENSTEIN


Designing Hygienic Equipment

Bacteria grows anywhere there is an adequate supply of water, protein, and air, particularly in areas where the temperature is warmer than room temperature. In practice, some of these areas can be cleaned with an alcohol or bleach-based cleaner to kill bacteria. Some areas, however, are difficult to clean, especially in assembled machinery: under fasteners, in overlapping components that are not sealed, on roughened surfaces, in corroded areas, etc. Unless the entire assembly can be taken apart and immersed in a cleaning solution, these parts are likely to harbor some bacteria. 

In order to limit bacterial growth, surfaces should have no exposed recesses or crevices. They should be sealed to prevent moisture or other contaminants from entering any spaces, and the surface should be smooth so that it can be easily wiped clean.


axenia value line of servo actuators sealed against moisture and contamination

The axenia value line of servo actuators are sealed against moisture and contamination. Image used courtesy of WITTENSTEIN

Resistant Servo Actuators

WITTENSTEIN alpha's newest servo actuators are specifically designed to limit the spaces that are hospitable to bacterial growth. They are sealed against moisture and contamination, and their housings are designed with no crevices. 

In terms of mechanics, the axenia line is available with three motor sizes (32 Nm, 80 Nm and 200 Nm of torque). They can be driven with multiple gear ratios and can be equipped with a number of encoders and temperature sensors to accurately measure the speed and prevent overtemperature. The overtemperature protection also prevents materials from melting or baking to the components, which can also harbor bacteria.

Each servo is sealed to meet Ingress Protection ratings (IP-69X), meaning it can be sprayed with water at up to 30 bar. This means no water, dust, or particles will enter the housing, even at high pressure. This allows for high pressure cleaning (a lesser rated housing would allow some water ingress which could feed bacteria growth as well as damage the internal components). 

The surfaces are polished to 0.8 Ra, yielding a smooth surface with no small crevices for bacteria to hide from cleaners. 


wittenstein hygienic servo actuator applications

WITTENSTEIN's hygienic design of products are suitable for use in the food, pharmaceutical, and cosmetics industry. Image used courtesy of WITTENSTEIN

Sterile Production

These servo actuators are a good fit for sterile production lines, such as those found in food and beverage or pharmaceutical manufacturing. These industries often issue recalls due to listeria and other contamination to consumer goods. In some cases, such as the baby food shortage, the contamination can lead to serious illness or death. Therefore, any place that can be made bacteria-free will improve the surety of the manufacturing process.

In pharmaceutical manufacturing, workers and devices are swabbed to see if any substance taken from them will grow in a petri dish. If bacteria grows, enhanced cleaning protocols are required. With the lack of surfaces for bacterial growth, this testing will likely yield very few unscheduled cleanings. 


Hygienic Solutions

Wittenstein has been developing automation solutions such as servo motors, gearboxes, actuators, and other components for several decades. Some of their most popular items include hygienic solutions for food and beverage manufacturing, low backlash gearboxes for precise automation, and custom services for tailoring motor and gear combinations to suit specific needs.