A food processing servo lives in a world that would destroy a standard industrial actuator within a week. Not water — every other servo handles water. The real threat is the 80°C caustic foam sprayed at 100 bar every single shift change. A dairy plant in the Netherlands replaced six positioning actuators last year because their IP67-rated units could not survive the nightly CIP cycle. The seals held against immersion, but the housing corroded from the outside in.
Picking the right actuator for a washdown environment means understanding what IP ratings actually cover and what they leave out. Here is what matters on a food production line.
Why Standard Waterproof Ratings Fail in Food Plants
IP67 and IP68 sound impressive on a datasheet. They mean the unit survives submersion in still water. But a food processing servo never sits in still water. It gets blasted with high-pressure jets from six inches away. That is IP69K territory — a completely different test standard that covers close-range, high-temperature, high-pressure spray.
Beyond the rating itself, the housing material matters just as much. Stainless steel resists the acid-based cleaners that food plants use. Aluminum housings pit and corrode within months, and once the surface roughens, bacteria colonies form in the pits. A food-grade actuator needs a smooth, crevice-free exterior that drains completely. No exposed fasteners, no threaded holes facing upward, no label plates with adhesive that traps moisture underneath.
What to Look for in a Food Processing Servo
Sealing is the obvious starting point, but chemical compatibility catches more people off guard. The caustic wash solutions in meat and dairy plants attack standard nitrile O-rings. You need EPDM or FFKM seals. The grease inside the gearbox also needs attention, because standard lithium grease washes out or emulsifies under repeated thermal cycling. Food-grade lubricants rated H1 for incidental contact survive these conditions.
The cable exit matters too. A bottom-exit cable gland fills with water if the installer does not angle it correctly, and once moisture wicks up into the housing, the servo fails from the inside. Top-exit or side-exit connectors with a drip loop solve this, but the design choice has to happen at the specification stage. You cannot field-modify a molded cable gland.
How the Duty Cycle Changes Everything
A packaging line servo that indexes trays every two seconds runs a completely different thermal profile than the same unit in a warehouse conveyor. The frequent start-stop cycles in food processing generate more heat, and the washdown environment means the housing cannot use cooling fins or ventilation. All heat dissipates through the stainless steel shell into ambient air or, worse, into the 40°C air above a running pasteurizer.
Because of this, continuous torque ratings mean more than stall torque. A food processing servo that stalls at 100 kg·cm but only holds 60 kg·cm continuously will overheat in under an hour on a high-speed filling line. Look for the continuous torque at operating temperature, not the room-temperature stall number printed on page one of the brochure.1