The best way to handle frozen food, agree several experts, is as little as possible. That means the materials handling equipment and information technologies used in a frozen food warehouse or distribution center (DC) need to move product as quickly, efficiently, and cost effectively as possible while minimizing worker exposure to low temperatures.

Exactly how that gets done depends on a range of factors. Exposure of workers to cold is one consideration. So is the mix of full pallet picks compared to case picks and mixed pallet handling. In fact, the mix of how inventory is handled directly affects the choice of automation or manual handling.

Overall costs are still another consideration with grocery margins so thin. Building a standard dry warehouse typically costs $40 - $60 per square foot. A freezer without automation might cost closer to $80 - $100 per square foot due to the refrigeration system, the floor composition, and the building envelope, says Richard Rodgers, director of solution consulting for HK Systems (262-860-7000).

While those base costs create their own pressure on frozen food handling, there are many options when it comes to handling and tracking inventory. And typically, the best practice at a particular DC depends on the specifics of that operation.

Generally, the more case picking done in a frozen food facility, the more automation is a candidate. 'A grocery DC might have 30 - 50 people picking mixed case pallets, so you can quickly get to justification numbers,' says Brian Hudock, principal at Tompkins Associates (800-789-1257). 'It's very hard to justify a high level of automation where you're only doing 5% case picking.'

The freezer's temperature also dictates the degree of automation considered. The colder a freezer is, the more automation there is likely to be because it is a less comfortable environment for workers. Freezer environments tend to be dimly lit to reduce heat produced by lighting, and tightly packed with high cube storage to minimize square footage.

Such factors create an opportunity to implement an automated storage and retrieval system (AS/RS), says Jim Neuner, director of business development for SK Daifuku (800-253-1003). 'The AS/RS stores the product in the freezer and transports the product out to a more reasonable temperature zone where the operators pick the orders,' Neuner says.

Also, labor costs are very high in a freezer DC, as regulations require periodic breaks for workers to thaw out between trips into the extreme cold. 'A worker in the freezer typically costs 1½ times the expense of a worker in an ambient [+65°F/+18°C and up] environment,' says RK Long, HK Systems' vice president of integrated systems sales. 'That helps justify automation such as AS/RS, automatic palletizers, robotic palletizers, and conveyors.'

Not every company can justify full automation in a frozen picking operation. At that point, companies tend to select more manual handling techniques.

Widely used are two stalwarts - conventional rack and lift trucks. Both handle inventory effectively but prolong the time workers are exposed to the cold.

Just as with other types of food, frozen food is typically handled on a first-in/first-out (FIFO) basis, says Paul Pisarcik, senior manager for Sedlak (330-908-2100). To accomplish this, pallet flow rack can be used in the freezer for full case distribution, and carton flow rack is used for broken case picking.

Conveyors, too, work in the freezer for unit level picking, but with less steep inclines to prevent frosty stretch wrapped packages from slipping, says Don Derewecki, executive vice president of Gross & Associates (732-636-2666).

'Conveyors into the freezer also need to be 'broken' at the opening of the wall to prevent conduction of heat into the freezer via the air and the conveyor frame,' continues Derewecki. 'If the conveyor doesn't run 24/7, a guillotine door separates and closes off the freezer so you don't have cool air escaping and warm air going in.'

If manual handling is the best practice selected, keeping workers warm is a top priority. All wear protective thermal jumpsuits, boots, and gloves.

Generally, the colder the freezer, the more frequent their breaks. This usually ranges from 20 minutes in and 20 minutes out for a long-term storage freezer, to 40 minutes in and 20 minutes out in a holding area for out of freezer picking. Therefore, giving workers the tools to help them be as efficient as possible when they're in the extreme cold temperatures is a top priority.

For instance, pick-to-light and put-to-light have been implemented with success in freezer environments, as have handheld radio frequency data communication (RFDC) terminals. While workers' thick gloves can impede use of this equipment, it provides effective real-time inventory management information that expedites freezer handling.

Bar code scanning itself can potentially be difficult due to possible frost on stretch wrap or on the lens and display of the terminal. However, there are now displays with heating elements that prevent frost.

Another data capture option is voice-directed picking, which is becoming much more widespread in freezers says Mike Miller, director of industry marketing and consulting for Vocollect (412-829-8145).

'Using voice typically offers bigger benefits than other techniques due to the nature of the environment and the protective clothing,' says Miller. 'Being hands free and eyes free tends to have an even bigger impact on employee productivity in these conditions.'

Workers who are simply transferring full pallet loads in and out of a freezer environment often work in a fork or turret truck with a heated cab. Of course, 'If they have to get on and off the truck repeatedly, then the heated cab becomes a problem,' points out Tompkins' Hudock. 'It releases too much heat into the environment and the cost of energy to maintain the low temperatures is very high.'

Almost every kind of materials handling equipment available can be used in a freezer, as long as it has been specially configured. Conveyors need special belts that reduce slipping and remain flexible. Motorized equipment, like fork trucks, should be battery operated with an extra heavy-duty battery and require special lubricants that won't thicken in the low temperatures. Cold-tolerant tires must be specified to prevent flattening on the bottom, and from slipping as frost melts and condensation develops when the vehicle moves to warmer temperatures.

Pneumatic devices aren't recommended for the freezer due to potential damage from frost, although if their compressors can be located outside of the freezer space they're still an option. Bearings should be sealed, labels require special glue, and all equipment should be designed to both ease and minimize maintenance. Small bolts and nuts can be impossible to adjust in a movement-restrictive thermal jumpsuit and gloves, agree the experts.

Above all, to determine the best materials handling practice for a freezer facility, says SK Daifuku's Neuner, one should answer these questions: what environment is best suited for the workers, how much automation can be cost-justified, and what vendors have the most experience in the frozen environment. The answers will help any frozen food handling DC keep their freezer handling to a minimum, while maximizing productivity, efficiency, and worker safety.

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