Shutting the Door on Pathogens

Because of floor drains and water accumulation from wash downs, the floor is a common source for bacteria growth and the roll-door bottom bar can make contact with these contaminant pools. As another measure of protection against this microorganism habitat and bioaerosols, manufacturers are adding a sloped bottom bar to their roll-up curtains. The design prevents water from dripping on product by channeling it off to the side of the doorway.

No Pooling. Walls that separate freezer areas must be properly insulated, as must the doors that cover the doorways leading into them. Doors that fail to minimize heat transfer can provide a cool surface on the warm room side of the door, turning the door panel into a condenser and creating water droplets and an environment for microorganism growth.

Whether the doors are solid panel or, for high-traffic doorways, roll-up style, the doorways must be insulated properly to handle the temperature differentials between the freezer area and the room outside. Even roll-up doors with insulated curtains do not equal the insulation provided by a solid wall. And with heavy traffic, these doors rarely stay closed for long. To minimize air infiltration, these doors must open and close rapidly.

When door are shut, curtains must provide some measure of insulation. When doors fill the role as vapor barriers between cold room and the warmer area on other side of wall, the operation enjoys the dual benefit of minimizing energy loss and reducing contaminated air infiltration.

An uninsulated door on this kind of a doorway becomes a condenser when the cold room chills the warm side of the door. When the door is closed for a period of time between accesses, moist air can hit the chilled panel surface. Water will form and then pool up on the floor. Not only does the pooled water create a pathogen breeding ground, but the slippery floor can lead to worker injuries.

No Admittance for Undesirables

As always in the real world of the plant floor, it is impossible to keep airborne bacteria, yeast, and mold in food processing areas at a zero level. Nevertheless, combating the assault of airborne contamination on food is a multifront war that processors fight with a variety of weapons.

Installation of recirculating air infiltration units, constant monitoring, consistent room temperatures, and even limiting employee traffic are among the many means to reduce contamination throughout the route to the shipping door. Though total confinement of pathogens to their place of origin is beyond practicality, proper door selection and application can ensure that food travels through the plant safely and that an unacceptable level of the microorganisms do not.

Angermeier is vice-president, marketing, for Rytec High Performance Doors. Reach him at [email protected].