May/June 2021 - 21

CLIMATE CONTROL
door panels need to match the R-rating of the room's walls.
Speed also counts. The faster the door opens and closes,
the less time for cold air to escape the room. With operations
optimizing floor space by using high racking in storage
areas, increases in door speed minimize doorway exposure.
The difference Is in the doors
Given the unique areas throughout a produce processing
plant, here are the door design choices available to plant
management.
Fabric roll-up. For quick access, offering operating speeds
of up to 100 inches per second. Separates room temperature
differentials of up to 35°F. Full perimeter seal, including a
soft bottom edge that conforms to floor profile. Breakaway
design enables automatic curtain reset for minimal doorway
exposure. Curtain panel material can withstand frequent
washdowns. Side guides and header can be available in
stainless steel. Door profile means installation in areas
where wall space is tight.
Sliding solid panel. For years, produce handling
operations where temperature differentials between rooms
is more than 35°F have lived with thick yet lumbering doors
with sliding door panels. These were perfect targets for
forklifts, leading to panels being bent out of shape, and gaps
forming between the door seals. Or worse, panels getting
penetrated by the force of the forces or knocked off the
walls, stopping the operation.
The door industry's latest development is sliding doors
with an impact-resistant design, a feature food handling
operations could not envision even a decade ago. As there
is no floor hardware to guide panel travel, when a forklift
clips a panel, it swings 90 degrees out of the way. Along
with saving maintenance costs, the impactable design means
that the doorway is always sealed to protect product quality
and traffic continues to flow.
Even when the door does get hit, the driver can keep on
heading onto the destination because the door's auto-reset
panel guidance system returns the door panels to a fully
sealed position, ready to open for the next forklift.
In addition, these doors' fast operating speed - 50 inches
per second for single panel doors and 100 inches per second
for bi-parting models - leaves little opportunity for crosscontamination.
Versus vertical roll-up doors operating at the
same speed, a bi-parting door can provide faster access to a tall
doorway and that means less exposure time for the opening.
The doors have R-17 rated 4-inch panels, with a cleanable
thermoplastic outer shell. Adding to facility cleanliness,
solid panel doors can be designed without drive chains
and wood reinforcements in the panel to eliminate fibrous
contamination.
A down-and-in track design provides superior sealing
of the full perimeter gasket system without compromising
gasket longevity.
Bring on the air force
Perhaps one of the most-ideal solutions to protect product
quality in busy produce processing facilities is no door, but
FACILITY OPERATIONS
 Thick, solid sliding panel doors are now capable of withstanding forklift
impacts while protecting temperatures in freezer environments.
rather a top-of-the-doorway air blower system to keep the
cold side of the wall cold and the warm side warm. This
approach creates an invisible barrier using high-velocity
laminar technology.
As the diagram shows, the laminar system creates a dual
air flow of pushing back warm air and a cold air barrier.
And as cautioned in Ghostbusters, the air blower system
does not cross these streams.
Regarding that other flow - traffic - it can move nonstop
between areas, within bringing fog and water vapor
along for the ride. Moreover, there is total visibility through
the doorway while ice and water buildup at the doorway
is combatted.
These air blower systems can be installed on doorways
using roll-up, sliding panel or even standard doors. This
system is so effective that operations can allow the door to
be open throughout the shift and not compromise the safety
of the area. As a result, the doors that are on these doorways
have a greatly extended operating life preserving their ability
to tightly seal, with greatly reduced maintenance costs.
Because the doorway is protected by air current rather than
solid materials, this system brings the concept of a " smart
door " to processing doorways. Using programmable controls
the air blower system can automatically adjust to temperature
and humidity changes to maximize energy efficiency.
With advancements in door design, a facility does not
have to settle for a door that kind of fits in with their need
for doorway protection of food safety. Produce processors
can have a door that more closely fits their processes, floor
traffic and budget.
- Josh Brown is the vice president of sales at ASI Doors. He
has over 20 years of experience in the material handling and
door industry servicing industrial and commercial markets.
He can be reached at jbrown@asidoors.com.
PRODUCE PROCESS ING
21
May/June 2021

Table of Contents for the Digital Edition of May/June 2021
