Asusceptor is a material used for its ability to absorbelectromagnetic energy and convert it to heat (which in some cases is re-emitted asinfraredthermal radiation). The electromagnetic energy is typicallyradiofrequency ormicrowave radiation used in industrial heating processes. In the consumer world, manymicrowave cooking tools as well as some disposable cooking vessels used withinduction heating employ susceptors.

Inmicrowave cooking, susceptors are built into paper packaging of certain foods, where they absorb microwaves which penetrate the packaging. This process raises the susceptor patch temperature to levels where it may then heat food byconduction or byinfrared radiation.

• Conduction heating occurs with good thermal contact between the susceptor and food. Because of the lower temperatures there is less browning, but more than if there were no susceptor at all.
• If there is an air gap (or at least, poor thermal contact) between the susceptor and food, the susceptor will heat to a much higher temperature (due to its smaller effectiveheat capacity when in poor contact with food), and, at these higher temperatures, will radiate strongly in theinfrared. This infrared radiation then shines onto the food below or next to the susceptor, causing a "broiling" type effect (high skin heating) due to lower ability of infrared to penetrate foods, vs. microwaves. Conversion of some microwave energy to infrared is particularly useful for foods which require a large amount of crust-browning from infrared, such as frozen pies.

Susceptors are usually made ofmetallised film,ceramics ormetals (such asaluminium flakes).

Susceptors meant to heat foods by direct conduction may be seen in the gray lining of packaging directly holding the food, and generally in good contact with it. For this reason, products meant to be browned via susceptor-generatedthermal radiation carry instructions to microwave the food while still inside its packaging.

A typical example is the paper-susceptor–lined dish directly holding a microwaveablepot pie orcasserole. This is useful for crisping andbrowning foods, as well as concentrating heat on the oil in amicrowave popcorn bag in order to melt it rapidly.

Among the first microwave susceptors marketed were those from the mid-1980s in a product calledMcCain Micro Chips byMcCain Foods. It consisted of a susceptor sheet which cookedFrench fries in amicrowave oven. These sheets are currently used in several types ofpackaging for heating and cooking products in microwave ovens. Care in package design and use is required for properfood safety.^[1]

A "crisping sleeve" is a device made ofpaperboard and affixed with a susceptor used both as a rigid container to support the food items within and to focus heat on the foodstuff.^[2] They are generally intended for a single use.^[3]Hot Pockets were an example of a product which used crisping sleeves; a new formulation that does not need a crisping sleeve was introduced in June 2024.^[4]

Microwave crisper pans and trays convert microwave into infrared to heat food.^[5][6]

• Microwave heat distribution

• Kumari, Saroj; Kumar, Rajeev; Agrawal, Pinki R.; Prakash, Shiv; Mondal, D.P.; Dhakate, Sanjay R. (October 2020)."Fabrication of lightweight and porous silicon carbide foams as excellent microwave susceptor for heat generation".Materials Chemistry and Physics.253 123211.doi:10.1016/j.matchemphys.2020.123211.S2CID 224862524.
• Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009,ISBN 978-0-470-08704-6
• "What does the cardboard plate in your microwave do?".Coolblue B.V. Retrieved6 April 2023.
• "1981 Corning Microwave Crisper ad".eBay. Archived fromthe original on 6 April 2023. Retrieved6 April 2023.

• "Susceptor heating" on commercial website
• Susceptor heating film on fast food package with carbon-based coatings

• Cooking appliances
• Packaging materials
• Electromechanical engineering
• Microwave technology
• American inventions

• Articles with short description
• Short description matches Wikidata