Doors would do their best if they were shut 100 per cent of the time. But that, of course, is impractical. Doors that open and close quickly, provide sound safety features, deliver good temperature and humidity controls, maintain utmost hygiene through their design and washdowns, self-reinsert if impacted and operate automatically are the next best thing.
High-speed fabric doors can help meet these needs, particularly for coolers and freezers. A few companies offer both standard and custom solutions ranging from $1K to $20K or higher per opening. The good news is, depending on the amount of energy savings these doors can deliver, both new and retrofit projects are eligible for rebates from a variety of states, as well as energy utility grants, to make payback as short as one to two years per opening.
“We just finished a $100K project for a customer in Denver,” says Chuck Zimmerman, vice president of sales for ASI Technologies in Milwaukee, WI, “and we got them in touch with the local branch of Excel Energy that got them an $18K rebate from the energy savings they were able to achieve.” Meanwhile, Marketing Director John Schumacher of Milwaukee WI-based Rite-Hite Doors cites Focus on Energy in his state and says he’s seen rebates as high as 50 per cent of project cost.
Soft technologyASI Technologies began in 1965 as a supplier of door systems for the food industry. The company then expanded to general industrial and pharmaceutical markets, giving it a leg up on hygiene and clean production design. “We make every type of swing door, personnel door and four- to six-inch sliding cooler and freezer door made of fiberglass and steel for good washdown performance,” Zimmerman explains. “We also manufacture single-panel, bi-parting and track doors that can slide around overhead rail systems, and high-speed fabric roll-up doors that can open and close at up to eight feet in one second.”
Speed is important to keep one environment, and temperature zone, separate from another. The faster the door moves, the greater protection it provides against ambient contaminants and the greater money it saves by preventing cold and warm air transfer. “Less warm air infiltration prevents frost and humidity build-up, which helps to improve productivity, minimize energy costs and reduce vehicular damage,” Zimmerman explains.
One of the reasons ASI fabric doors can move so quickly is that they’re made of soft, USDA-compliant fabric with no rigid bottom bars. They have a soft bottom edge and an integrated reversing device to enhance worker safety.
If impacted, ASI doors reset themselves automatically. They don’t require lubrication, reducing any risk of drips on products passing through on forklifts below. Their edges are angled to direct any condensation away from sensitive areas.
The company recently completed a project in an Illinois food distribution facility which complemented its series of high-speed roll-up units with laminar-flow air doors to provide added temperature and humidity control along with frost and ice prevention. Fans are direct shaft driven as opposed to being driven by maintenance-intensive belts. The units can also inject heat into the air stream automatically in real time to manage moisture saturation between different temperature zones.
“Often, mornings are more humid while evenings cool off. Our systems compensate automatically in real time through a series of temperature and humidity probes. Integrated PLCs and HMIs perform these functions plus a host of other operational and tracking functions,” notes Zimmerman. ASI systems can also utilize waste heat from refrigeration lines to provide a source of free heat. The horizontal laminar airflow is designed to capture as much warm air as possible for recirculation and to provide further operational efficiencies.
In another installation for a frozen food producer, ASI was able to solve a frost build-up, fog and moisture problem between the plant’s -10
Zipper edgeDynaco Doors, located in Mundelein, IL, prides itself on safety, speed and the quality of its seals. The company’s patented technology provides high-speed operation without rigid curtain components. Its curtain is made from reinforced PVC and features a soft, flexible bottom edge. “Because of our soft technology and the improved safety it provides, our doors can open and close at 96 inches per second and 60-72 inches respectively,” says Dynaco National Sales Manager Robert Atterson.
The side guide features a zipper design that allows the door to reinsert when accidentally dislodged by a forklift. Inner guides are made of UHMW-ultra-high molecular weight polyethylene-which encapsulates the curtain zipper edge to provide a secure seal with minimal wear and maintenance.
Driving the doors is a push-pull system that eliminates rigid wind stiffeners and bottom bars. Standard IP65-rated motors use an absolute encoder and frequency inverter to provide rapid acceleration and deceleration without the need for motor brakes.
Dynaco approaches new customers with an Excel spreadsheet that outlines how much energy its doors can save in dollars per year depending on temperature deltas, how big the door is and how many times it opens and closes. Every door comes with a standard wireless reversing edge and an infrared photocell, installed 12 inches off the floor to detect the presence of a person or vehicle. Upon detection, the door instantly reverses and remains open until the obstacle is removed.
Dynaco’s SlimLine doors were installed at a 47,000-sq.-ft. expansion at snack food maker Shearer Foods Inc. of Massilon, OH in 2010. The project’s many high-tech and sustainability features earned Shearer’s the 2011 Plant of the Year award from Food Engineering.
“We were looking for high-performance doors for our expansion,” says Shearer’s Director of Engineering Scott Hamilton. “We heard Biery Cheese, which is nearby, installed them and were very happy with the result. So that’s the direction we took.” He says the doors are very easy to clean, can stand a lot of traffic and are fast. “We installed them between our processing and packaging room, which is air conditioned to prevent seasonings on our chips and other products from bridging. There’s about a 25º to 30º temperature difference between the two zones, and we needed these doors to maintain separate climates.”
Albany Door Systems is a division of Albany International, a global company that has its headquarters in Albany, NY. This company has numerous product lines used in food manufacturing. One of them, UltraTough, is a high-speed roll-up door with a rubber curtain that can be used for both interior and exterior openings.
Though rubber does not provide a high R-value (numerical measure of heat transfer through an object), it does a good job of resisting high and low temperatures, and is very durable. “It’s a medium-price choice that’s ideal for harsh environments,” notes Albany Marketing Manager Joe Aiken. The company’s ThermaChill and ThermaFreeze doors are made from Climatex-two layers of vinyl wrapped around heavy-duty polyethylene air pocket insulation. They provide a 4-5 R factor and can withstand temperatures from -40ºF to over 100ºF with a 40ºF temperature variance.
For loading dock applications, Albany’s UltraFast doors travel at up to 60 inches/second by wireless control; no coil cords are needed. “The doors break away and reset quickly during accidental impact, are energy efficient, easy to use and economical to maintain,” notes Aiken.
Albany’s self-resetting UltraClean high-speed fabric doors are designed for high-traffic sanitary applications. In addition to fast opening and closing speeds, their two-piece side column design and stainless steel components allow for easy washdown and cleaning. Bottom bars are rigid but wrapped in foam and offer an automatic reversing edge for safety.
“Our MCC Control system, which drives the doors, uses variable frequency technology that’s easy to use and features a soft start and soft stop capability,” says Aiken. “Many high-speed door companies have variable speed controllers, but our vector control only uses power as needed, saving energy.” The system also has a graphic user interface or GUI that’s scrollable. In addition to controlling door movement, it tracks the door’s performance-how often the door cycles in a given time, if and when it’s been impacted, and other events. Moisture and frost are controlled by the company’s low- or high-volume airflow systems and infrared light in conjunction with heat tape applied to strategic locations.
Track-based alternativesRite-Hite focuses on faster speed and total door cycle time, while maintaining a high enough R-value to avoid the use of heat lamps and air doors to control condensation and frost. “In many cases, we can save our customers as much as $5,000 to $15,000 per door opening per year in energy costs,” says Schumacher.
Rite-Hite provides a variety of roll-up, bi-parting and bi-rolling designs. For vertical types, most companies roll their high-speed fabric doors onto an overhead drum. Rite-Hite pushes its doors up into a track, either straight up or radial. Its curtains also employ soft edge technology to promote plant safety.
Using its unique track system gives Rite-Hite the flexibility to use thicker curtain material, which would otherwise be difficult to roll up. The track can be configured to almost any shape to avoid having to move pipes, electrical connections and other fittings. As a result, the company can offer higher R-value in its high-speed fabric door solutions.
Rite-Hite’s FasTrax clean door is designed specifically for food processing. It minimizes surface-to-surface contact points (crevices where bacteria can hide). The rails and tracks are made from UHMW plastic and stainless steel to eliminate corrosion from thorough washdowns.
If impacted, panels automatically refeed back into the tracks. Doors can be ordered in a variety of colors, not so much for aesthetic considerations, but for identifying raw areas from cooked in a food facility.
One limitation of high-speed roll-up or track-based doors is they don’t provide much security if used at an outside opening. In this case, double-door systems are the answer-high-speed doors during production hours where there is a high level of traffic, complemented by heavy-duty steel or composite doors that can be closed and locked at night.
Kurt Angermeier, vice president of marketing at Rytec Doors of Jackson, WI, says his company’s high-performance fabric roll-up workhorse is called Clean-Roll. This door meets a combination of USDA, FDA, NSF and ISO standards. One unique feature is a stainless steel piano hinge that attaches the fabric to the drum roller. It can be power-washed and has no hidden pockets where bacteria, dirt, old water or soap could otherwise accumulate. Both the top and bottom areas of the door have drip guards that prevent water or anything else from dripping onto product as it passes through the opening below.
For freezer applications, the company’s Turbo-Seal door has multiple options. The panel is made from a proprietary Rytec material called Rylon Therma. It’s 1.5-inches thick and uses closed cell foam on the inside surface for insulation. “It has no air pockets, no stitching, and is essentially a monolithic piece of material. As the door opens, the roll gets thicker, increasing speed,” says Angermeier.
Motors are direct drive and can be fitted with optional counterbalances to reduce wear and tear. The trade-off to counterbalances, however, is added maintenance. Like other Rytec doors, the Turbo-Seal is completely washable and comes with three air curtain options to prevent frost build-up.
Higher insulationChase Doors in Cincinnati, OH specializes in impact traffic doors, cold storage doors and corrosion-resistant fiberglass doors. Impact traffic doors are designed to increase productivity from fast, efficient, two-way movement through a door opening. Cold storage doors provide significantly higher insulation than their impact traffic door counterparts-anywhere from R28 to 37, compared to R8-12 and R4-5 of high-performance automated roll-up doors. There are three different designs of a cold storage door: sliding, swing and vertical lift. Both sliding and vertical lift doors can be manually operated or automated, but open and close at a much slower rate than high-performance fabric roll-up doors. Fiberglass doors are designed for use in corrosive environments. They can be used for interior and exterior applications and can be fire label rated up to 90 minutes.
A variety of materials can be used to construct an impact traffic door. One option is rotationally molded, cross-linked polyethylene and an injected non-CFC urethane foam core. “The advantage is that the polyethylene material stands up to a variety of chemical cleaning solutions, and its seamless construction allows for full water washdown without the concern of bacteria growth or premature door failure,” says Chase Doors Marketing Manager Sandy Ball.
Beef Products Inc of Dakota Dunes, SD, is one of the world’s leading manufacturers of lean beef from trimmings, processing millions of pounds of product per week in four facilities in four states. The company’s approach to doors is somewhat unique, explains Engineering Coordinator Tom Woolley.
“We work with a stainless steel fabrication plant called Fusion Tech in Roseville, IL, and they custom build our doors according to our own specifications,” he says. “The doors are purposely overbuilt for minimum maintenance and maximum durability-our doors are so strong they’ll last a lifetime.” Types include electrically operated overhead doors, sliders and man doors. Woolley says they take about three times the labor to install, but even so he says the company saves money compared to buying ready-made doors for its particular needs, and never has to worry about maintaining or replacing them.
Door technology is keeping pace with increasing demands by food processors. The good news is choices are abundant and payback can be remarkably fast-not only from ongoing energy savings, but also from the many state and utility rebates that are available for new and retrofit installations.
For more information:
Chuck Zimmermann, ASI Technologies, firstname.lastname@example.org, 414-464-6200
Jon Schumacher, Rite-Hite Doors Inc., email@example.com, 414-944-1717
Robert Atterson, Dynaco, firstname.lastname@example.org, 317-490-8114
Joe Aiken, Albany Door Systems, email@example.com, 770-338-5000
Kurt Angermeier, Rytec Doors, firstname.lastname@example.org, 262-677-6170
Sandy Ball, Chase Doors, email@example.com, 513-603-2946