Opening Doors to Automation

  • June 09, 2014
  • Feature

By Keith Schmitz, Rytec High Performance Doors

At the ultra-clean and newly expanded MINOR’S food processing plant in Cleveland a forklift picks up a bin of their product and carries it into the next room along the line, entering through an airlock to minimize the entry of airborne pathogens into the packaging area. But unlike most facilities the forklifts here never take a break other than for a battery charge because there is no one sitting in the driver’s seat.

Nor is there a driver activating door operation. The signal to open and close is generated by the same process management system directing forklift travel.

MINOR’S has joined the growing ranks of companies that are putting automated material handling (AMH) vehicles to work, seeking increases in productivity and lower operating costs. A recent article in Fast Company on robotics’ pending pervasiveness reveals that Google is developing a driverless car that has already logged 500,000 miles. So it’s no surprise in the more controllable world of the manufacturing plant and with industry’s growing need for efficiency, speed and reliability; material handling vehicles will be acquiring minds of their own.

The recently released Material Handling and Logistics US Roadmap, complied by the national supply chain publications and associations, looks at the industry ten years into the future. Among the ten megatrends unfolding in the next decade, the report predicts that “autonomous control and distributed intelligence” could one day extend to driverless equipment in the warehouse and over the road.

Engine maker Rolls Royce envisions unmanned “drone” cargo ships, though many in the industry don’t think they will be sailing any time soon. Nevertheless, these technological changes will be driven by a changing workforce, the growth of e-commerce, mass personalization and of course never-ceasing competition - all of which have impact on the factory or distribution center floor.

 Industry isn’t waiting for 2025. A report published by the Priority Metrics Group detailed that AMH vehicle sales exceeded $15.5 billion world-wide in 2011, up 18% over the previous year. This represents roughly 15% of the investment in new equipment.However, these vehicles also cannot wait for the doors within the plant to get out of the way.

Within these plants are walls sectioning off rooms; and like walls, doors are supposed to preserve the integrity of the processes or the inventories in the room while allowing traffic to pass in and out of the room. Just about every room maintains its own microclimate with a proper temperature. Humidity and air flow are controlled for whatever process takes place or for the product handled within it.

Doors ensure that these areas maintain those conditions, protecting the room from pressure differentials, extreme temperatures sparks, fumes, drafts, noise or other conditions in the previous room that could adversely affect work in process, employee productivity and building energy costs. But if the doors can’t get out of the way in time, progress goes nowhere.

To keep pace with AMH equipment and the systems that demand this speed, the doors along the material path must be able to do the following:

Open and Close Rapidly – The lumbering sliding panel door is a thing of the past. For any door to be a member of today’s material handling team it must be an overhead roll up style to get out of the way of vehicles and to attain the high speeds necessary for efficient product flow. These doors also take up minimal wall space to maximize these areas for shelving or machinery.

These doors now are capable of speeds of 60 inches per second and faster, and can be fully opened in under two seconds for a typical eight-foot high door. The rapid roll up door minimizes room exposure, giving practically no time for energy to escape or contaminants to invade.

At MINOR’S ultra-pure food processing facility, their specially designed automated guided vehicles (AGVs) transport product from one room to another. The concern of process engineers at this operation is to minimize contaminants throughout the processing chain. To maintain product quality, entrance/exit is through an airlock system, facilitated by the speed of their Rytec Clean Roll® automated high-speed roll up doors.

As unmanned vehicles make their way through the airlock system at the ultra-clean MINOR’S plant, the doors automatically open to clear the doorway.

As well as opening in seconds to minimize infiltration from the positive pressure air circulation system, the roll up curtain is easy to clean.  It also has other features that meet the requirements for current Good Manufacturing Practices (cGMP) as defined under the Food, Drug, and Cosmetic Act.

Create a Handshake with the Management System – New design control boxes bring these doors into the automated material handling system. The sophisticated electrical systems that now control door operation have easier installation and smaller, space-fitting enclosures. Intelligent processors and variable frequency drives generate an efficient speed curve for smooth motion, soft starting and soft stopping. As a result, the controls use less energy and prolong door component life.

Processors enable doors to become another node in the automated process by creating a “handshake” with the material handling system, responding to commands from the other equipment along the material-handling route.

The forklifts at the Preferred Refrigerated Services distribution center in Elizabeth, NJ are not automated. Within this advanced design cold storage 10-million-cubic-foot distribution center, a 140,000 square foot lights-out sub-zero freezer and a higher ceiling make better use of the building footprint.  The distribution center encloses a 72-foot-high automated storage and retrieval system to efficiently manage all put-away and order fulfillment. The controls on the Rytec Turbo-Seal® high-speed roll-up doors are integrated with the warehouse management system.

Door operation is coordinated with the operation of the automated pallet picking system inside the PRS freezer to minimize the time the pallet spends on the loading dock.

The handling system enables precision order fulfillment with rapid product transfer, and doorway access for top performance. The high-speed roll-up doors along the freezer enable rapid access to the pallets brought in and out of the freezer.

The doors’ advanced electronic System 4controls team up with the WMS for smooth product flow. The forklift drivers at the dock picking up a pallet, via onboard computer, notifies the WMS they are on their way to the freezer. Once at the freezer doorway, the system activates the door to quickly open for pallet pickup by the robotic crane for eventual put-away.

To ship, the WMS communicates with the forklift-mounted on-board computer to notify the driver a pallet will be waiting at a designated freezer door. The instant the forklift arrives the pallet is deposited by the crane outside the doorway. The system greatly reduces idle time and energy loss.

Ensure Virtually Zero Downtime – Automated systems represent significant investments, and a second of downtime is fatal to the return on investment. Something as simple as door down-time can bring the whole system down, especially if there is something in the previous area.

Both the door speed and advanced electronics contribute to the door stamina. While making something go faster usually guarantees a shortened life-span for any product, the moving parts on a roll up door actually experience very little stress and rarely need to be replaced.

In fact door speed is indirectly proportional to the amount of damage it suffers. The speeds of these doors make hitting the door just about impossible, even if the vehicle does not slow down when it is heading to the doorway.  Even though many of the flexible curtain roll-up doors have the benefit of breakaway bottom bars that can be easily reset when hit to avoid damage, thanks to door speed this feature is rarely used.

Seal the Doorway Tightly – Other than the brief time that a high speed door opens and closes, once it is shut, like the wall it is attached to, the door must thoroughly aid in enclosing the room. That environment in the room has been painstakingly specified to match the processes taking place in it, and any leaks around the doorway impair the integrity of the room.

That means the door must be tightly sealed all around its parameter. With roll-up doors, the side guides also fully enclose the panel vertical edges. On fabric panel doors, curtain stiffeners along with the side guides prevent positive/negative pressures from bowing out the door panels. Brush seals at the top stop air infiltration as do the gaskets along the bottom bar.

Currently, many of the operations that can justify investment in AMH vehicles involve technology and other products sensitive to contamination. Rapidly changing technology and the growing use of it in manufacturing and material handling will put this method for moving product within the reach of more facilities.  

So it is with door technology. Advancements in door design are proving that every component in a process today be considered for improvement and making greater contributions to the operation. Doors have reached the point where the manufacturers’ experts can be in the conversation with your material handling engineers when it comes to developing 21st century systems.

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