Foodservice Equipment Reports

Serve And Protect

Serve and protect perfectly describes the unsung mission of trays used in correctional meal delivery. The compartmented units necessary to serve food to inmates are expected to keep food hot, be cleanable to avoid cross-contamination and staining, and be durable enough to resist damage. Trays are protecting, one might say, the reputation of your facility’s foodservice department in the eyes (and stomachs) of its incarcerated clientele. 

With that in mind, let’s examine meal delivery trays in depth. Read on for tips on what questions to ask before specifying trays, the pros and cons of various tray materials and construction, durability and temperature testing tips, warewashing advice, and take a look at what kinds of trays are just emerging on the market.

Questions Before Spec’ing

There are hundreds of correctional trays available. Narrowing down the styles right for your facilities calls for some pre-choice homework.

“Before you get attached to any vendor or distributor, you have to answer some basic questions about the unique requirements of your facility,” says Pattie Whitlock, president of Design Specialties, Hamden, Conn. She ticks off a quick list:

  • Do the inmates come to a cafeteria or is food delivered to the inmates? If you’re doing congregate feeding, a basic compartment tray will work. For cell feeding, options include insulated trays to hold food at the proper temperature, ovenable trays for retherm operations, and heated carts to transport regular trays with covers.
  • If you deliver food, how long does it take for delivery? And do you need to go outside or in a truck to make the delivery? This will help determine the type of insulated tray you choose, be it solid, air-filled or foam-filled.
  • How many compartments are necessary? Are there enough compartments to hold all meal components, including flatware and beverage? “No one wants empty compartments or for food to be ‘lost’ in the tray,” Whitlock says.
  • Will the tray fit all your tallest, longest food items, including apples, milk cartons, cake, broccoli spears, pancakes and the like? “The tray must be deep enough so food doesn’t spill or touch the bottom of the tray above it when stacked for delivery,” Whitlock notes.
  • What are your size limitations? Will the trays fit through door slots in all of your cells? Will the trays fit in your existing carts? How about in your warewasher and drying racks?
  • Do you need individual tray lids, or will self-lidding stackable trays be sufficient?
  • If you serve congregate style, what happens during a lock-down? Will you have enough additional trays to accommodate the extra in-cell feeding?
  • How do you accommodate special diets?
  • What is the security level of the facility?
  • What trays have you used in the past? What did you like and dislike about past products?


The correctional tray industry has come a long way since the days of stainless steel trays. Trays can be made of a range of plastics or plastic blends, and can be insulated (filled with foam or air) or solid (the same material throughout). Newest on the market are pliable trays made of silicone or elastomers. Below we describe the benefits, drawbacks, temperature range and durability of the leading tray materials.

Copolymer, a blend of polypropylene and polyethylene, results in a softer, slightly flexible tray that’s become perhaps the most-used material in correctional meal delivery. It is commonly used as the exterior layer on insulated trays. Copolymer is “quite economical,” according to manufacturers, and very durable. The material will not break down from repeated warewashing. Drawbacks: Copolymer’s softer plastic makes it easy to scratch and it’s prone to staining from acidic foods. When a copolymer insulated tray develops a crack or hole, water can get trapped inside during warewashing, causing the tray interior to mold, smell or lead to illness. Temperature range: 40°F to 210°F.

Polypropylene can be used to make solid, durable, insulated trays that are the same material throughout—so no danger of cracks or water damage. They’re also fully recyclable. Cortech Correctional Technologies, Willowbrook, Ill., offers a lidded version of these trays with a tongue-and-groove seal between lid and compartments. This feature helps prevent tray contents from spilling into the next compartment due to rough handling. Drawbacks: These trays cannot be used in microwave ovens. Temperature range: -40°F to 220°F.

Polycarbonate is the hard plastic material often used for trays in low- and medium-security facilities, especially for cafeteria feeding. Its hard surface resists stains and scratching (so it’s safe for metal flatware). Its higher tensile strength means polycarbonate trays tend to be thinner and lighter than copolymer, making for easier handling. The shiny, attractive surface dries faster than copolymer. Drawbacks: Polycarbonate trays are priced about 40 percent higher than copolymers and will become brittle over time from repeated warewashing. Temperature range: -40°F to 230°F.

Polyphenylsulfone is an amber-colored, highly heat-tolerant plastic resin used for rethermalizing foods in cook-chill operations. It is often formed into rectangular containers designed to fit in a tray compartment—for example to add a hot entrée to an otherwise cold meal—but you also can buy it as a compartmented tray. Polyphenylsulfone products, which are break-, stain-, and scratch-resistant, tend to be one of the more expensive options. Temperature range: -40°F to 400°F.

Extremely pliable materials such as silicone and elastomers are among the latest tray innovations. Both feature the strength and flexibility needed for segregated feeding of the most violent inmates—neither can be sharpened into a weapon, and both are extremely hard to tear apart. But be aware that if punctured, these trays can be ripped apart and used inappropriately.

Silicone trays, introduced to the segment in 2007 by Cook’s Direct, Warrenville, Ill., feature non-porous surfaces that keep food from sticking, making trays easier to wash. The material’s broad temperature range makes these trays suitable for cook-chill operations—you can store prepared trays in the freezer, retherm on-site, and, since silicone does not transmit heat, deliver them straight to inmates. Ribs on the bottom keep fully loaded trays from flexing too much and spilling. Drawbacks: the price point for silicone is about 25 percent to 50 percent higher than copolymer trays, depending on volume and whether or not you opt for stackable or non-stackable models. Temperature tolerance: up to 450°F.

Elastomer is a hybrid blend of plastics that has a rubber-like texture and feel. Elastomer trays can be used in microwave ovens or heated carts. Drawbacks: Elastomers are more expensive than copolymer and polycarbonate but less expensive than silicone. Temperature tolerance: up to 250°F.

Construction & Design

As with materials, there are plenty of tray styles to choose from. We’ll look at insulated foam-filled and air-filled trays, solid trays, lids vs. no lids, and touch briefly on the various shapes and compartment options.

First up: foam-filled vs. air-filled. Foam-filled trays have a “definite edge in temperature retention compared to air-filled,” says Vince Fantin, Jones-Zylon regional sales manager. Foam-filled trays are also more expensive due to the extra steps needed in manufacturing. Both types of tray, however, if punctured or otherwise damaged, can take in water during warewashing, leading to mold growth, unpleasant smells and potential health hazards.

Solid trays tend to be even more durable, depending of course on thickness and build. They also retain heat well. Unlike foam- or air-filled trays, there’s no danger of mold contamination due to water infiltration. However, if the surface sustains a deep scratch or gouge, it provides a place for bacteria to grow. Both air-filled and solid trays can be recycled at the end of their useable lives, while foam-filled trays cannot.

Design-wise, trays are offered in two- to seven-compartment versions in a range of sizes and depths. Inmates expect something in every compartment, so if you opt for a many-compartment model, make sure you have a plan to fill each section.

A condiment compartment will let you save money on packets of, say, ketchup, by buying in bulk and portioning sauces in the kitchen.

Some trays lack a flatware section for a reason. “A lot of facilities collect utensils separately so they can make sure they’ve been returned,” notes Paul Novak, sales v.p. for Cortech. “Trays with lids make it especially easy for inmates to hide the fact that a utensil is missing.”

Many facilities rely on stackable, self-lidding trays for a couple of reasons. “Lids become one more item that can be turned into a weapon,” says Food Services Manager Larry Mendez, who oversees feeding of 7,000 inmates and wards at the San Diego Sheriff’s Food Services East Mesa Central Production Center. “Plus lids slow the process for security staff handling cell feeding; they have to account for every item.”

PlastOcon makes a stackable tray that’s recessed on the underside to make sure the food below doesn’t touch the tray above. “Prisoners don’t want to see someone else’s food on the bottom of their tray,” says Jerry Marks, national sales manager at PlastOcon, headquartered in Oconomowoc, Wis. Other trays sport enough depth that food-to-tray-bottom-contact is not an issue.

Tray thickness matters when it comes to cleaning, too. If you’re specifying a deep tray, make sure your warewasher is equipped with the right belt to convey trays upright through the machine, positioned so that sprayers reach compartment recesses.

Temperature Tips

“Hot food, served hot” goes a long way toward keeping inmates satisfied with their meals. Which is why testing potential new insulated trays at your operation is crucial. At the Michigan Department of Corrections Coldwater Complex, with about 2,600 inmates, Food Service Director Kevin O’Brien pulled out the thermometers to test tray candidates.

After requesting samples of all the trays he was considering, O’Brien’s team filled each one with food from the steam table. “We measured the food temperature in each tray every 15 mins. It turned out that 45 mins. was about the longest that the best tray could keep food at an acceptable serving temperature,” says O’Brien, who also serves as the Michigan Chapter president for the Association of Correctional Food Service Affiliates.

Insulaied trays might keep food hot longer, but only if they’re used correctly. “The trays work like a thermos—they retain heat, but they can’t add it,” PlastOCon’s Marks says. “You have to make sure that the food going into trays is as hot as possible, at least 180°F to 200°F. The act of transferring food from steam table to tray will cost you an immediate 20° to 30° temperature drop, and the food will continue to lose about 10° per hr.—faster during cold weather.”

Also, make sure you match the food portion to the compartment size. “A spoonful of beans in a large space will spread out and lose heat faster,” Novak at Cortech says. “Inmates are often doing the serving, and they have to be trained on where to put foods.”

Wash And Wear

A tray’s usable life depends not only on your prisoner population but also on such factors as your menu (acidic foods such as tomato sauce can stain softer plastic materials), water supply (hard or soft), warewashing chemicals and usage.

“You’re using the same units over and over,” O’Brien says. “They get stacked, scraped, pushed through openings and more. When you notice the plastic starting to crack or peel, it’s time to throw that tray out.”

Staining, be it from acidic foods or inmate graffiti, can be made less obvious by choosing darker tray colors. And stains are less of an issue if they’re cleaned promptly. “No one wants to eat from a dirty-looking tray,” O’Brien says.

In Summary…

“There’s no right or wrong answer where trays are concerned, since different facilities have different requirements and personal preferences,” Whitlock says.

“Make sure you trust your supplier so you’re getting the proper tray to meet your needs, and not just the products they sell,” she adds. “Your supplier should understand how the tray will be used so you won’t be putting the trays into environments where they won’t work.”

Tray Handling Dos and Don’ts 

PlastOcon shares a list of common-sense tips for extending tray life.


  • Keep trays and lids away from intense heat of any kind, such as open burners, hot coffee urns, etc.
  • Equip flight-type dish machines with tray guides to prevent jamming and tray damage. 
  • For longer tray life, consult your rep for detergent and rinse agent information. Caustic chemicals and high chlorine solutions can cause premature stress cracks in trays.
  • Do monthly titration metering of detergents and rinse agents to avoid tray damage.
  • Make sure the tray-wash rack is activating the rinse solenoid when trays are washed in a multi-tank, pass-through rack conveyor machine.
  • Speed air-drying by aligning trays vertically, with space in between. If trays are stacked atop of each another while still damp, rinse and detergent residue can corrode tray surfaces.
  • All plastics are susceptible to staining. The longer the stain is allowed to set, the harder it will be to remove. Since most trays float, pour the de-staining solution into the affected compartments and stack trays loosely. Manually agitate the stained areas and then re-sanitize the trays. 


  • Never expose trays to temperatures above or below their tolerance. Extreme temperatures can cause distortion and warping of trays and covers.
  • Never autoclave trays.
  • Never exceed surface temperatures of 160°F if heated entrée plates (ceramic or melamine) will be in direct contact with the tray surfaces.

Tray Vendors: A Sampling

Design Specialties

Cambro Mfg.

Cook’s Correctional

Cortech USA


PlastOcon Inc.

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