JPH03505020A - Susceptor with segmented areas for differential heating in a microwave oven - Google Patents

Abstract

A packaging system is disclosed which includes a susceptor heating means having selective responsiveness to microwave radiation. The susceptor surface has a plurality of regions, where at least one region has an altered responsiveness to microwave radiation which is achieved by disruptions in the susceptor surface. A method for making regions of a susceptor selectively responsive to microwave heating by disrupting the continuity of the metallized film of the susceptor is also disclosed.

Description

[Detailed description of the invention] Differential heating in the microwave A susceptor that has a divided area for Until now, seeds were used to bake food in the microwave to give it a different color or to break up the surface. There were various problems with each attempt. Microwave ovens are different from regular ovens. Heat food using the following method. Generally speaking, how much microwave radiation does food absorb? This results in a significantly different heating process than in a regular oven. A thermal pattern develops. Additionally, microwave radiation penetrates most foods and This results in a heating pattern that is significantly different from that produced in the oven. in most cases Microwave energy heats food faster than a regular oven. for example, Foods that require 30 minutes to properly "cook" in a regular oven can be "cooked" in the microwave. "Cooking" takes only 3.4 minutes.In a regular oven, the atmosphere inside the oven The air is heated to a relatively high temperature and transfers the heat to the surface of the food, so that the surface of the food is always the most This is a hot area. In the case of a microwave oven, the atmosphere inside the oven is generally heated. Instead, the food itself generates heat and transfers that heat to the surrounding air, so the surface of the food It will be colder than inside. These differences can cause the surface of food to turn brown in the microwave. The ability to sear and break up the surface is significantly affected.

Do not burn the surface of food in a microwave oven, or burn the surface to pieces. Many attempts have been made to do this.

One such attempt is to use a packaging component called a susceptor. It is about things. A suitable susceptor is prepared by placing a matrix on top of a microwave transparent support layer. Includes those with microwave absorbing coatings. These susceptors are micro Generates heat when exposed to wave radiation. The susceptor burns the surface of many foods to a brown color. Reach temperatures high enough to burn or burst into pieces. Susceptors are food It is placed in direct contact with or in close proximity to the surface. typical commercially available The susceptor contains a thin film of aluminum vacuum deposited on polyester, which is laminated with adhesive to paper or board.

However, the use of susceptors creates other problems. Commercially available susceptors are generally uniform. Cannot be heated. As a result, these susceptors are able to brown food evenly. You can't make it look like a burr. For example, the outer region of a susceptor is It becomes significantly hotter during microwave radiation than in the area. As a result, the outer part of the food It will turn brown or crumbly, but the center part will be cooked as long as you do not overcook the outer parts. Don't be like that. This is, for example, the baked outside shell of a large frozen pizza. This is a particular problem in foods with large surface areas. using a susceptor pad For example, if you focus on a large number of fish sticks lined up horizontally on a susceptor, During stripping, microwave heating typically removes the fish step from the end of the susceptor. The fish stick in the center of the susceptor pad is sufficient. Don't get too busy.

Yet another problem when using a susceptor to heat food is that It is impossible to control the heating profile.

Adjust the amount of heat output in different sections of the susceptor to accommodate different food properties. It is often desirable to This can cause browning or clumps. This is particularly problematic when two or more foods with different requirements are placed against a common susceptor. It is. During heating, the contact surfaces of the food that are made up are overcooked, but the adjacent Food contact surfaces become half-cooked.

When cooking food by microwave radiation, the total amount obtained during the heating process is Particular attention must be paid to physical energy balance. microwave radiation strength Or simply increase the cooking time to brown or burr certain areas of the food surface. other surfaces and/or the inside of the food itself may become overcooked or may be overcooked. In other words, simply increase the heating time or browns the central region of the pizza shell by increasing the intensity of microwave radiation If you are trying to break up or break up the pizza, the outside surface of the pizza may be overcooked or overcooked. and/or the pizza toppings may be overcooked.

When heating food in a microwave oven, especially when using a susceptor, The balance of energy absorbed throughout is usually complex. Sasep This will prevent the food from turning brown or falling apart in the microwave. Solved the susceptor problem of not being able to heat uniformly, although the degree of heating was improved. The need arises. To uniformly brown or break up food with a susceptor There has been a demand for a means to do so. In addition, the heat required to properly heat all parts of the food Uniformly browns and burrs without disturbing the complex energy balance There was also a need for a means to do so. You can also mix different types of foods in different brown colors. There is also a desire to make it more or less obvious.

An example of an attempt to break up the surface of food is U.S. Patent No. 4.26 by Mr. Blastad. No. 7,420 and U.S. Pat. No. 4,230°924 to Prastalad et al. It is. In order to make the surface of the fish stick brown, Mr. Prastalad Shape a flexible wrapping material that wraps completely around the fish stick. I tried to accomplish this. However, Mr. Blastad is able to evenly break up the food surface. They are not paying attention to the problem of not being able to do it. In addition, Mr. Prastarad is flexible. This article discusses how to compensate for non-uniform heating caused by different wrapping materials. do not have.

Another example is Oscar E. Seyfarth, US Pat. No. 4.641.005. Ru. This patent discloses a thin film susceptor for heating food products. However However, Mr. Seyfarth does not pay attention to the problem of non-uniform heating on the susceptor surface. . In addition, Mr. Seyfarth also discussed how to compensate for food burdens. It also does not disclose how to compensate for the preferential edge heating of the rotor.

As is clear from the above explanation, the surface of food cannot be broken apart in a microwave oven. None of the known attempts have been satisfactory.

The use of a susceptor may cause the surface of the food to become unevenly burred or create unwanted uneven surfaces. heating patterns often occur.

According to the present invention, there is provided a system for heating food in a microwave oven. A system is provided that can be used to more uniformly heat the. this The system includes susceptor means containing conductive regions of variable size. Conductivity The size of the region is adjusted to compensate for possible undesirable non-uniform heating patterns. It will be done.

The susceptor means is in direct contact with the surface of the food to be burred or browned. or placed close to it. The susceptor means is generally a conductive coating, typically a sheet with a metallized film on it, the metallized film being exposed to microwave radiation. absorbs microwave energy during exposure to Therefore, the susceptor means Heating in response to microwave radiation. According to the present invention, each conductive coating has a different The area is divided into multiple areas with susceptor areas of the same size. These sasse The susceptor area may be cut, for example, so as to disrupt the conductive coating of the susceptor means. Inserting, cutting, etching, die-cutting, printing, etc. is formed by other means. At least one region is configured to receive microwave radiation. Its responsiveness to thermal effects is modified by the disruption of the conductive coating.

Parts of the susceptor that otherwise tend to overheat are exposed to microwave radiation. A small susceptor area is provided to avoid confusion.

Parts of the susceptor means that are otherwise underheated are relatively susceptible to microwave radiation. A large susceptor area is provided that feels good.

By adjusting the size of the susceptor area within the scope of the present invention, It is possible to compensate for non-uniform heating patterns caused by heating.

This allows for a more even browning of the food and a crispy surface. . Alternatively, use uneven patterns to make the surface burly or brown. When desired, the present invention provides a specific desired heating pattern. The susceptor means are designed so that:

For a better understanding of the invention, the invention will be described in detail below with reference to the accompanying drawings. I will clarify.

FIG. 1 has two regions each formed with susceptor areas of different sizes. The top view of the susceptor pad, FIG. Graph showing the heating profile of the puta pad, FIG. 3 shows the same method using regions with different sized susceptor areas according to the present invention. Graph showing the temperature profile of the susceptor pad, FIG. 4 shows that susceptor areas of different sizes made according to the present invention can be spread on the food surface. A bar graph illustrating the effect on vignetting, FIG. Temperature pattern obtained during microwave irradiation on a susceptor that does not have a septa area Figure 6 is a diagram showing the image formed by an infrared camera. Similar diagram showing the heating pattern of a susceptor with variable size susceptor area by light This video, Figure 7, is used to break up the surface of foods such as pizza. A top view of a susceptor with variable susceptor area according to the invention, FIG. 8 shows a round pizza support without progressively sized areas according to the present invention. A graph showing the septa temperature profile, FIG. 9, shows the gradual size shown in FIG. Graph showing the temperature profile of a similar susceptor with a susceptor area of Figure 10 shows a variable size susceptor using the susceptor pad configured as shown in Figure 7. A bar graph showing the effect of Taeria on the browning of food surfaces. FIG. 11 is an image of the heating pattern of the susceptor configured as shown in FIG. 7, Figure 12 shows the image formed by an infrared camera, which is reached during microwave heating. a graph showing the temperature of the susceptor area as a function of the size of the susceptor area; Figure 13 shows the percentage power absorbed, transmitted and reflected by the size of the susceptor area. Figure 14 shows the graph as a function of the size of the susceptor area. A graph showing capacitance reactance, Figure 15 shows how to reduce the microwave heating effect on the separated region of the susceptor. a top view showing another embodiment of a susceptor using a maze pattern; Figure 16 shows the effect of dividing the conductive sheet without cutting on microwave heating. FIG. 17 is a top view of the susceptor showing the microwave A diagram showing an infrared image of the heating effect, FIG. 18 shows the infrared rays of the microwave heating effect on the susceptor shown in FIG. 16. Diagram showing the video, FIG. 19 shows a susceptor with four different response regions formed according to the present invention. top view, Figure 20 is obtained during microwave heating of the susceptor formed according to Figure 19. A graph showing the temperature profile, Figure 21, shows a susceptor using the principle of "directed flow". Figure 22 shows the unmodified sample used as a control example for comparison. The infrared image of the microwave heating effect on the septa, Figure 23, is based on Figure 21. Infrared images showing microwave heating of the constructed susceptor, FIG. 24 is constructed by FIG. 21 and then the central region of the susceptor and the A modified susceptor with an additional cut to break up the conductivity between the lip and the The top view, FIG. 25, shows microwave heating of the susceptor configured as shown in FIG. infrared images, FIG. 26 is a top view showing an example of a susceptor using the principle of "directed flow"; FIG. 27 shows the top of a susceptor of the present invention with a spiral cut to obtain a "directed flow". side view, FIG. 28 shows a susceptor of the present invention growing a square convoluted cut to obtain "directed flow". top view of the ta, and FIG. 29 is a top view showing another embodiment of a circular susceptor using "directed flow" .

A susceptor pad is used to break up the surface of the food product. the surface The food to be broken up is placed in close proximity to this susceptor pad 10 or placed in direct contact with it. The susceptor pad 10 is a layer of metallized polyester. This includes a thin film or deposit of a metal such as aluminum on top of a layer of polyester. It consists of what was done. The polyester layer acts as a support for the thin metal membrane.

A conductive layer of metal is deposited onto the polyester substrate by a vacuum deposition process. child The metallized polyester layer is preferably adhered to a support surface such as paper.

Details of suitable compositions for susceptor pad 10 are included herein for reference. “Package for breaking up the surface of food in microwave ovens” cage for Cr1spind the 5 surface of Food Products in a Microwave 0ven)' U.S. Patent Application No. 070,2 filed July 6, 1987 by Mr. R1 Periichi et al. Please refer to No. 93. Further disclosures of susceptor pads are taken for reference. “Food Receptacle for Microwave Cooking” for Microwave Cooking)'' by Oscar E. No. 4,641,005 to Firth.

When a susceptor pad with a continuous metallization layer is exposed to microwave radiation, , typically resulting in a non-uniform heating pattern as shown in FIG. heating like this is most pronounced at the edges of the susceptor pad, while its central part is well Not heated. Using such a susceptor pad, e.g. When breaking up the surface of multiple fish sticks placed side by side, The surface of the fishstick, typically located at the edge of the susceptor pad, is exposed to chroma waves. The surface will be broken, but the surface of the fish stick in the center of the susceptor pad The surface will not be sufficiently burred. At least fish sticks have an even surface. Don't be confused at first.

To compensate for the non-uniform heating that occurs when the susceptor pad is exposed to microwave radiation. It is desirable to have a means to do so.

In accordance with the present invention, variable size compensation is provided to compensate for undesirable non-uniform heating characteristics of the susceptor pad. A susceptor area is provided. As shown in Figure 1, on the susceptor pad lO is provided with a large size susceptor area in its central region 11 and its edges A susceptor area of relatively small size is provided in region 12 . microwave response The central region 11, which is relatively strong, includes a large susceptor area 13. microphone The end region 12 with weak radio wave response includes a relatively small susceptor area 14 .

In the example shown here, the conductivity of the metallized film is cut by the cut or score 15. It is cut off. Notch 15 is a metal cut made with a sharp instrument such as a razor blade. It is a cut in the chemical layer. Alternatively, the notches 15 can be made by pressing a sharp die into the susceptor pad 10. It may also be formed by basting. One susceptor area 13 and its adjacent A dividing part or a conductive discontinuous part is formed between the susceptor area 13 and the metal layer. Any means may be used as long as it provides a satisfactory result. example For example, conductive discontinuities can be etched, engraved, cut, embossed, or It may also be formed by a photoresist method. Surprisingly, the susceptor pad Simply separate the metallization layer by drawing a line with a ballpoint pen across the surface of the O. It turned out to be good. Generally breaks electrical connections in metal films Any method is effective. Notch 15 is also a small Metalization between the susceptor area 14 and the adjacent small susceptor area 14 Forming a conductive break in the film.

The small susceptor areas 14 are smaller than the large susceptor areas 13. It is also made small enough to have low responsivity to microwave radiation. subordinate Therefore, when the susceptor pad 10 is exposed to microwave radiation, the small susceptor pad 10 The susceptor pad area 14 is larger than the case where the susceptor pad 10 is not provided with the notches 15. will no longer feel the heating effect of microwave radiation. The small susceptor area 14 is In some cases, the responsiveness of the end region 12 to microwave radiation may be "detuned". )’ let.

The large susceptor area 13 is relatively sensitive to the heating effect of microwave radiation. The large susceptor area 13 reduces the "desynchronization" effect on the central region 11. It is thought that the Also, the large susceptor area 13 ensures uniform heating of the central region 11. Improve unity. Cut the susceptor area 13 in the central region 11 on this side. Otherwise, edge heating of the central region 11 would occur to an extent. Susceptor area 13 is , are formed in such a way that "desynchronization" effects do not occur.

In applications where the relative heating of one region 12 is greater than that of another region 11, Only less is important.

Configuration of the small susceptor area 14 and large susceptor area 13 shown in FIG. is to compensate for the tendency of the end regions 24 to heat up relative to the central region 11.

Figure 2 shows the sample used to heat fish sticks in a microwave oven. The heating profile of the septapad is shown.

FIG. 2 shows a susceptor pad without susceptor areas 13 and 14 of variable size. It is related to. Temperatures at various locations on the skin center line of this susceptor pad Degrees are measured using an infrared camera. Curve 16 is for microwave radiation Figure 3 shows the temperature profile of the susceptor pad after 30 seconds of exposure. curve 17 is the temperature profile of the same susceptor pad after 60 seconds of exposure to microwave radiation. It shows. Curve 18 is the same susceptor after 210 seconds of exposure to microwave radiation. It shows the temperature profile of the pad.

As shown in Figure 2, the temperature in the center of the susceptor pad is relatively high within 30 seconds. quickly heated up to temperature and then dropped by the time the temperature was measured at 60 seconds are doing. The temperature at the center of the susceptor pad is as shown by curve 18 at 210 seconds. It is kept at a low temperature through microwave irradiation. However, the susceptor pad The edges are kept at a relatively high temperature. As a result, in the edge area of the susceptor pad The fish stick is located in the central area of the susceptor pad. The surface also becomes more uneven. The surface of the fish stick is uneven and uneven. It was observed that Total cooking time for fish sticks is approximately 3.5 to 4 It was a minute.

Temperature was measured with an infrared camera. The infrared camera passes through the wire mesh shield. The temperature is “uncorrected” because the temperature was

Wire mesh shield prevents microwave energy from leaking from the microwave was used to. The wire mesh probably requires a low flat surface for the infrared camera. An even temperature reading would have occurred.

However, the relative temperature difference is important here. Therefore, the actual temperature value is accurate. However, it is believed that the relative temperature is accurately represented.

FIG. 3 shows the temperature profile of the susceptor pad 10 configured based on FIG. It shows. As shown in FIG. High heating is obtained by using a small susceptor area 14 in the end region 12. Ta.

Curve 19 shows the temperature profile of the susceptor pad 10 after 30 seconds of exposure to microwave radiation. It shows the file. Curve 20 shows the susceptor after 60 seconds of exposure to microwave radiation. The temperature profile of bat 10 is shown. Curve 21 is 21 for microwave radiation. The temperature profile after exposure for 0 seconds is shown. The temperature of the end region 12 is the curve 19 The 30 seconds measurement shown in curve 20 and the 60 seconds measurement shown in curve 20 keep the temperature relatively low. It sank. Furthermore, the temperature in the end region 12 increases towards the end of the heating time, as shown by curve 21. It rose.

FIG. 4 shows a small susceptor area 14 in the end region 12 and a large susceptor area 11 in the central region 11. The effect of septaarea 13 on the burring of the surface of fish sticks is shown. This is a graph. Multiple fish steps are attached to the susceptor pad lO shown in Figure 1. ku were lined up.

These fish sticks are placed parallel to each other in a side-by-side relationship. Ta. The length of the fish stick was oriented vertically in FIG. paraphrase Then, the length of the fish stick should be oriented in the same direction as the width of the susceptor pad lO. I got kicked. Therefore, some fish sticks are arranged entirely in contact with the end region 12. while the other fish sticks are in contact with the central region 11 entirely. Placed.

In tests using sensory-trained examiners, the flap touching the central area 11 The fish stick is used to break up the surface of the bread, as shown in bar graph 22 in Figure 4. There was an average lO% change (increase) in increasing the temperature. standard susceptor and Fissoustec prepared in a notched susceptor were examined compared by members. Fish contacting end area 12 of susceptor pad 10 The stick breaks up the surface of the bread, as shown in bar graph 23 in Figure 4. There was a -11% change (decrease) in this regard. These percentage changes are Cooked in a susceptor vat that does not include variable susceptor areas 13 and 14 This is based on a comparison with Fishstick. Therefore, the variable susceptor area 13 and 14, the surface of the fishstick in the central region i1 Increased burring and burrs on the surface of the fish stick in the end region 12 Causes reduction in burr formation. Therefore, the variable size susceptor areas 13 and 14 are During the microwave irradiation of the susceptor pad and fish stick combination, This compensated for any uneven heating that might occur.

The effect of the variable size susceptor areas 13 and 14 is compared in FIGS. 5 and 6. This will be further explained. FIG. 5 shows variable size susceptor areas 13 and 1. Images obtained with an infrared camera during microwave irradiation on a susceptor pad that does not contain 4. represents a statue.

Figure 6 shows the temperature profile of the susceptor constructed based on Figure 1. Ru. The infrared image in Figure 6 was obtained after 30 seconds of exposure to microwave radiation. Ru. FIG. 6 shows the 30 second temperature profile shown in FIG. 3 (indicated by curve 19). Corresponds to the file.

FIG. 6 shows that the microwave heating of the end regions 12 is considerably reduced compared to the central region 11. It shows that

In the susceptor pad IO shown in FIG. It is formed in a rectangular shape of about 1/16 inch on each side.

In other words, the small susceptor area 14 has a height and width of 0.0625 inches. It is formed in a rectangular shape.

A large susceptor provided in the central region 11 of the susceptor pad IO shown in FIG. The area 13 is rectangular in shape, 1-1/4 inches long and 7/8 inches wide. will be accomplished. Replacement: Then, the large susceptor area 13 is 1.25 inches long. , the width is 0.875 inches.

The illustrated overall length of susceptor pad 10 is 6-1/2 inches. The total width is 3- It is 3/4 inch. Each end area 12 is approximately 2 ga. by 3-3/4 inches. During ~ Central area 11 is approximately 2-1/2 inches by 3-374 inches. small & big A large susceptor area 13 that separates the susceptor areas 14 from each other and is adjacent to the susceptor areas 14 Notches 15 used to separate the metallized polyester layer were cut into the metallized polyester layer. It is the width of a razor blade.

Figure 7 shows a round susceptor pad used to brown the outside of a pizza-like shell. 24 is shown. When using a round susceptor to heat pizza, use the susceptor pad. The outer periphery of the pad tends to heat up significantly more than the central region of the susceptor pad. this gives the outer surface area of the pizza shell a brown color, but the central area of the pizza shell has a brown color. Only 0-60% becomes brownish. This is explained in detail below in Figures 8 and 8. This is shown by the material shown in Figure 10.

susceptor pad 24 while reducing heating of outer region 26 of susceptor pad 24. It is desirable to have some means of increasing the relative heating of the central region 25 of the . In the present invention, this is done by providing a conductive path in the outer region 26 of the susceptor pad 24. This is achieved by providing a notch or indentation 27. These notches 27 is in the form of a cut made with a razor blade or the like. These notches 27 If formed to divide or cut the conductivity of the metallized layer of the pad pad 24. That's enough.

The notch 27 creates a small susceptor area 28 in the outer region 26 of the susceptor pad 24. stipulate. The central region 25 defines a large susceptor area 29 . small susceptae The rear 28 is more susceptible to the heating effect of microwave radiation than the large susceptor area 29. I don't feel like it.

This is the outside of the susceptor pad 24 where the susceptor 24 would otherwise heat up. This has the effect of reducing the level of heating in region 26. Variable susceptor area By providing 26 and 29, the temperature of the central region 25 is increased relative to the outer region 26. Gives the effect of rising.

Figure 8 shows the temperature of the round susceptor pad used to brown the pizza shell. It is a graph showing a profile. Curve 30 represents exposure to microwave radiation for 30 seconds. Figure 2 shows the temperatures measured at various horizontal positions of the susceptor pad after the susceptor pad. song Line 31 shows the temperature measured at the same location after 120 seconds of exposure to microwave radiation. are doing. Curve 32 represents the temperature measurements after 300 seconds of exposure to microwave radiation. ing. Curve 33 shows temperature measurements after 390 seconds of exposure to microwave radiation. There is. Figure 8 shows that the outer part of the susceptor pad is lower than the center part of the susceptor pad. This indicates that the temperature will be quite high.

FIG. 9 shows a temperature profile of the susceptor pad 24 constructed according to the embodiment of FIG. It shows the ile. Curve 34 shows the susceptor pattern after 30 seconds of exposure to microwave radiation. 2 shows temperatures measured at various horizontal positions on the head 24. Curve 35 is my Temperature measurements are shown after 120 seconds of exposure to chroma radiation. Curve 36 is 300 Temperature measurements are shown after exposure for seconds. Curve 37 is 390 seconds for microwave radiation Temperature measurements are shown after exposure for a period of time.

Comparing FIG. 9 and FIG. 8, it can be seen that the use of variable susceptor areas 28 and 29 It can be seen that the temperature profile of the thermal susceptor 24 changes significantly. central territory Area 25 is a susceptor pad not constructed according to the present invention after 390 seconds of exposure. reaches significantly higher temperatures than the central region of the area. While the temperature in the outer region 26 decreases, the temperature in the inner region 26 decreases. The temperature in the central region 25 has been increased.

FIG. 10 shows susceptor areas 28 and 2 of different sizes on the susceptor pad 24. 9 is a bar graph showing the effect on the browning of the outer shell of pizza. Ru. This bar graph shows the percentage of the outer shell area that turned brown after microwave heating. It shows.

Bar 38 in Figure 1O represents a susceptor pack that does not have susceptor areas of different sizes. The proportion of the outer shell area is shown in brown using In this example, the pizza Slightly less than 80% of the outer shell area was browned. Bar graph in Figure 1O The outer area of the pizza shell is about 85% or more covered, as shown by bar 4o. Colored. However, as shown by bar 39 in Figure 1O, the central region of the pizza shell is Less than 60% turned brown.

As shown in FIG. 7, the susceptor areas 28 and 29 have different sizes. Using the septa pad 24 considerably increases the degree of browning that occurs in the central region 25. Additionally, the degree of browning that occurs in the outer region 26 is significantly reduced. Dedication 42 is , indicates the degree of browning that has occurred in the central region 25. In this example, the central region 2 Approximately 95% of the outer shell area of 5 was browned. As shown by bar 43 in Figure 1O, The outer shell area of outer region 26 was only about 5% browned. browned The total percentage of the outer shell area is less than 30% as shown by bar 41 in Figure 10. there were.

FIG. 11 is an image obtained by an infrared camera, which is constructed using the embodiment shown in FIG. The heating pattern of the susceptor pad 24 is shown. This infrared image is obtained at a point during the heating time corresponding to 390 seconds of exposure to microwave radiation. It is something. The infrared image in Figure 11 is shown in the temperature profile graph in Figure 9. This corresponds to the curve 37 shown in FIG. The area corresponding to the central area 25 and the outer area 26 is the This is shown in Figure 11.

In the particular susceptor pad 24 shown in FIG. It was 9 inches. The diameter of central region 25 was approximately 4.5 inches. small sasse The adapter area 28 typically has a height and width of approximately 1/16 inch or 0.0625 inch. It was formed as a square. The notches 27 are formed in the metallization layer of the susceptor pad 24. Formed by making cuts with a razor blade.

One area 26 of the susceptor 24 is made to be less susceptible to microwave heating. When this happens, the degree of heating of the undivided region 25 can be increased. This phenomenon This is called "load sharing." Make sure that one area 26 does not experience microwave heating. more energy can be used to heat other areas 25 when Conceivable.

Figure 12 shows the heating effect of a small susceptor area 14 as a function of area size. This is a graph showing In this case, the susceptor area is made rectangular. instructed The dimensions are the height and width of the rectangle.

FIG. 12 shows that the metallized susceptor pad 10 has a relatively When square 14 is made smaller than 0.625 inch on the side with higher resistivity The responsiveness of the small susceptor area 14 to the heating effect of microwave radiation increases rapidly. It shows that it will decrease. If the resistivity is as low as 18Ω/square, the microphone The responsiveness of small rectangles 14 to the heating action of radio wave radiation is determined by the fact that these rectangles are It decreases when made smaller than 0.3125 inch.

In FIG. 12, curve 44 shows that the resistivity of the metallization layer of susceptor pad 10 is 18 Showing the temperature as a function of size for a small rectangle 14 when Ω/sq. There is. Curve 45 shows that the resistivity of the metallization layer of the susceptor pad lO is 60Ω/square. The temperature is shown as a function of the size of the rectangle 14 when Curve 46 is metallized Size for the susceptor area 14 if the resistivity of the layer is 1650 Ω/square shows temperature as a function of . These temperatures are determined by the difference in emissivity of the susceptor surface. has not been corrected.

The relative temperatures along each curve (44, 45, 46) are correct. Samples with different resistivities The relative heating between the septa is influenced by the difference in emissivity of the susceptor surfaces and It has not been corrected in Figure 12.

FIG. 13 shows the 60 Ω/sq. Data obtained with a network analyzer for susceptor pad 10 is shown. 5i The square uncut susceptor pad 10 is shown in the rightmost part of the graph in FIG. The indicated reflectance, transmittance and absorption measurements were given. For uncut buds, Absorption was measured to be approximately 30%. The reflectance was measured to be approximately 68%.

Furthermore, the transmittance was measured to be approximately 2%.

Figure 13 shows the reflectance, transmittance and absorption of the susceptor pad lO on the susceptor surface. It is shown that it is affected by a discontinuous part, that is, a discontinuous part of conductivity. dividing part i.e. The size of the rectangle 14 formed by the discontinuous part of the conductivity is 0.625 on one side. The curve begins to change noticeably as it goes below inches. Percentage absorbed Power was significantly reduced for squares less than 0.625 inch on a side. The width is For the 0.325 inch square 14, approximately 33% absorption was measured. Width is approximately 0 ．． Approximately 27% absorption was measured for the 3125 inch square 14. The width is approx. Approximately 20% absorption was measured for the 0.1563 inch square 14. The width is Absorption of about 11% was measured for square 14 of about 0.078] inch.

All measurements were taken on a net before heating the susceptor pad 10 in the microwave. This was obtained using a work analyzer. This technology, i.e. network analyzer The technique using data is to define a simple rectangle 14 as shown in the example above. A susceptor with discontinuous or conductive discontinuities forming a complex pattern It can be used to measure decreased responsiveness of the tabad area. Therefore, ma Decreased responsiveness to microwave heating can be seen in the illustrated example of square 14 as well as in It can be obtained using a discontinuous pattern, that is, a discontinuous part of conductivity, of various shapes.

The effect of the discontinuous part on the susceptor surface, that is, the discontinuous part of the conductivity, can be seen with reference to Fig. 14. be understood. Figure 14 shows when a small square 14 is formed on the surface of the susceptor. is a graph showing the effect of the impedance of the susceptor pad on the reactive component. . The data plotted in Figure 14 is for the same sample with an initial resistivity of 60Ω/square. This was measured using a network analyzer using a septapad. In particular, The impedance of the susceptor pad is for an uncut 5 inch square susceptor pad. Before cutting, essentially All are resistant.

The discontinuity in conductivity on the surface of the susceptor pad creates a negative reactance, i.e. a capacitive generated reactance. The total impedance Zs of the susceptor pad is as follows: is expressed in

Zs=Rs-jXs However, Rs is the resistance component of impedance, and Xs is the reactive component of impedance. It's a minute. If Xs is positive, the reactance is inductive. Xs is negative In some cases, the reactive component is capacitive. Cutting area on the conductivity of the susceptor pad surface In other words, if the surface of the susceptor pad is not continuous due to discontinuities, , susceptors typically exhibit capacitive reactance.

Measuring the reactance of the susceptor surface reveals discontinuities in the area of the susceptor surface, i.e. An indication of the size of the break is given. This is due to heating during microwave irradiation. The responsiveness of that region is affected by discontinuities or breaks on the susceptor pad surface. proportional to the extent to which it is applied.

Capacitive reload in various regions of the susceptor pad 10 caused by breaks in the susceptor surface The relative difference in actance determines the response of one area to the heating action of microwave radiation. means for determining whether the response is small compared to another area of the susceptor pad IO; It can be used as Therefore, using a complex pattern, the susceptor pad surface A divided portion can be formed on the surface. Network analyzer measurements are complex The susceptor pattern is sensitive to the heating effect of microwave radiation as a result of the discontinuities in the pattern. can be used to determine whether the responsiveness of a region of the head has changed.

Figure 15 shows a complex “maze” pattern that forms divisions on the susceptor pad surface. This is an example of the present invention. In the case of the complex pattern shown in Figure 15, the net Work analyzer measurements indicate the relative responsiveness of various areas to microwave radiation. It is used to judge.

FIG. 15 shows a susceptor pad having discontinuities or breaks in the form of a maze pattern. The first region 47 of FIG. The divided portion of this first region 47 is Responsiveness to the heating effect of microwave radiation when there is no division on the susceptor surface decrease.

Also, in this example, the second region 48 is shown as a central rectangle of susceptor material. Ru.

The divided portion on the susceptor surface does not necessarily have to take the form of a cut on the surface. stomach. The susceptor surface can be divided by drawing lines with a ballpoint pen, for example. Good too. For example, dividing parts formed with a ballpoint pen may reduce responsiveness. An example of this is shown in the experimental results shown in FIG. In this example, we use a rectangular susceptor pack. 49 is used. The grid pattern covering the first area 50 allows the ballpoint pen to be It is depicted on the susceptor pad 49 using Three circular areas 51 are arbitrarily selected , and there is no dividing section. Relative of two susceptor pads The heating is shown without a grid pattern in Figures 17 and 18. In FIG. 16, each is shown with a grid pattern.

Figure 17 shows an image formed by an infrared camera showing a susceptor pad with no separated parts. It shows the heating action and use for. This susceptor pad is used for control in this example. used.

Figure 18 shows the susceptor pad 4 on which a grid pattern has been drawn using a ballpoint pen. This is an infrared image of the heating effect on 9. The surface of the susceptor pad is separated. The relative difference in heating of the three circular regions 51 without It should be clear from this. In this experiment, the heating response of the region of the susceptor pad is affected. The effect of the resonant divide is shown. Therefore, the actual cutting of the susceptor pad surface Department is not required. The disconnected portion is created by applying pressure or embossing to the surface of the susceptor pad. It may also be formed by grinding. In addition, there are virtually invisible divisions. may be formed. However, the action of the dividing section can be evaluated using a network analyzer. This can be clarified by the measured values obtained.

FIG. 19 shows first regions 5 each having a different pattern of conductive discontinuities on its surface. 3. Susceptor pad 52 having a second region 54, a third region 55 and a fourth region 56 It shows. In this example, a rectangle 57 is formed by the fourth region 56. square 5 7 has a width of 1/2 inch. Square 57 is cut into susceptor pads using a razor blade. It was formed by making a cut 61 on the surface of the board 52.

The third region 55 has a small rectangle 58 formed by the cut portion 61, and its width is is approximately 1/4 inch. A smaller rectangle is formed in the second region 54, Its width is approximately 1/8 inch. The first region 53 is formed by the cut portion 61. The width of the rectangle 60 is approximately 1/16 inch.

FIG. 20 shows the temperature profile of the susceptor pad 52 configured based on FIG. 19. It shows the The heating effect of the microwave radiation in the fourth region 56 is similar to that of the other regions. 53, considerably larger than the heating effects in 54 and 55. rectangular area The smaller the noise, the smaller the degree of heating observed. Temperature is measured using an infrared camera Measured.

Cuts or divisions in the surface of the susceptor create a "directed flow" It can be used to form an effect called floW)J. This is the first This will be explained with reference to the embodiments shown in FIGS. 21 to 25.

FIG. 21 shows the susceptor pad 62. On the surface of this susceptor pad 62 Parallel cuts 62 are made. At the center of the susceptor pad 62, there is an uncut A central area 64 of the area is left.

Parallel cuts 63 define strips 65 on the surface of susceptor pad 62 . Sase There is a conductive discontinuity between the central region 64 of the strip 62 and the end of each strip 65. There is no dividing part.

Figure 22 is an image obtained with an infrared camera showing the heating of a susceptor without a cutting section. It shows a pattern. This was used as a control measure for the experiment. No. Figure 23 is an image obtained with an infrared camera, showing the susceptor configured based on Figure 21. 62 heating patterns are shown. Strong heating effect in central region 64 is evident It is. A strip 65 connected without a break to the central region 64 is connected to the central region 6 It is thought that this promotes the heating of 4.

FIG. 24 shows a susceptor pad 66 constructed based on FIG. 21. , in this case an additional cut 67 is made to separate the strip 65 and the central region 64. It is dividing or cutting off the connections between the two. Figure 25 is an image obtained with an infrared camera. 24 shows the heating pattern of the susceptor pad 66 constructed based on FIG. It is. As in the example shown in FIG. 21, the heating in the central region 64 is not significant. .

FIG. 26 shows another embodiment of a susceptor pad 68 using the "directed flow" principle. ing. In this example, the susceptor pad 68 is suitable for use in, for example, pizza. It is a circular susceptor. The susceptor pad 68 shown in FIG. It has a cutting part or dividing part 69. This cutting section 69 is located in the central region, that is, the target A strip 70 is defined that extends radially inwardly toward a storage area 71 . these The strip 70 is connected to the central region 71 without a break. Target area 7 1 is placed at a position other than the center of the susceptor 68.

A second cut 72 is provided extending only partially towards the central region 71 . A region extends radially outward from the center of the pad 68 to the end of the second cut section 72. A second region 73 is defined by the area. As a result, the relatively high temperature central region 71 It is formed. The second region 73 is located at a lower level than the outermost region 74 of the susceptor pad 68. Generally high temperature.

Generally, the more cuts 69 are provided on the susceptor pad 68, the more the central region 71 becomes It becomes high temperature. Furthermore, the uniformity of heating of the outermost region 74 of the susceptor pad 68 is , improved by increasing the number of cutting parts 69 provided on the susceptor pad 68. It has actually been observed that

of the central region 71 to break the conductivity between the central region 71 and the strip 70. A circular cut can be provided around the circumference. In this example, the central area 71 is It has been observed that the temperature preferentially increases during chroma wave heating, but as shown in Figure 26, The central region 71 of the sea urchin does not reach as high a temperature as it would if it were connected to the strip 70 without a break. No.

Another embodiment of a round susceptor 75 is shown in FIG. In the example shown here, A plurality of cuts 76 extend radially inward from the outer periphery toward a central region 77 .

Cuts 76 define a plurality of strips 78 extending radially from a central region 77. . On this side, all cuts 76 are made from the periphery of the susceptor 75 to the edge of the central region 77. It extends. All other things being equal, the central region 77 of the example shown in FIG. has a higher temperature than the central region 71 in the example shown in FIG.

Various shapes are used to demonstrate the principle of "directed flow".

For example, a round series as shown in Fig. 27, a rectangular series as shown in Fig. 28, and a bit. Wheel-shaped cuts, cross-shaped areas, etc. have been tried. all these varieties The shape of the is a relatively hot center connected to strips of various shapes without separation This demonstrates that it is possible to form a region.

The central region generally has maximum support where the principle of ``directed flow'' works most efficiently. It has been observed that it has an is. If the area in the center area is too large, The central area does not reach high temperatures. The maximum size of the central region is determined by the resistance of the susceptor pad material. It is considered to be a function of the rate. The lower the resistivity, the larger the central area; Efficiently produces significant heating of the area. Generally speaking, the smaller the central area, the The heating effect on the central region becomes stronger, ie at a higher temperature.

The surface of the susceptor is initially configured to have discontinuities or cuts in the conductive layer. You can make septa. The application was filed at the same time as the present invention and is included here as a reference. In the patent application entitled “Microwave heater and its manufacturing method” by Mr. Geru Turbine et al. Contains further explanation.

In the above explanation, measured values such as resistivity, reflectance, transmittance, and absorption are not specified. All samples were obtained at room temperature (21"C) unless otherwise noted.

In addition, in the above explanation, all the measured values obtained with the network analyzer are related to the following method. It is something to do. Huuret Paracard Model NQ8753A Net Work analyzer and Hewlett Paracard Model Na85046A An S-parameter tester was used in combination. All measurements are at L45GHz The test was conducted at the microwave operating frequency. Also, unless otherwise specified, all Measurements were performed at room temperature. All measurements were performed using a WR-282 waveguide. .

Reflectance, transmittance and absorption measurements were made without the presence of food.

The measurement is carried out by placing the sample to be measured between two adjacent parts of the waveguide. It is preferable to do so. Sample sheet cut slightly larger than the cross-sectional opening of the waveguide Preferably, a conductive silver paint is placed on the outer edge of the. Ted Pe1la, A colloidal silver paint made by Inc. has had practically satisfactory results. I did it. The sample measures approximately 50/1000 of an inch (0,127 cm) around its edges. m) are preferably cut so that they overlap. Waveguide is a network Specified and published by Hewlett-Paracard, the manufacturer of the Calibration is performed based on the procedures described.

Scattering parameters 5IIsSIff, Sl+ and S! 2 is this network analyzer directly measured by Then, using these measured parameters, the map The microwave output reflectance, output transmission and output absorption are calculated.

The reflectance entering the boat l has a magnitude of SI, squared. Reflectance to boat 2 is the square whose size is S□. The transmission rate to boat 1 is S! It is the square of +.

The transmission to boat 2 is S12 squared. Power absorption to boat 1 or boat 2 The factor is equal to 1 minus the output reflectance and output transmittance to the boat.

The complex surface impedance of electrical thin sheets is taken here for reference. Volume 39 of “Journal of Applied Physics” , No. 1, pp. 3883-84 (July 1968) R, L, R amey and T.S. Lewis, “Thin Metals at Microwave Frequencies” Properties of Th1n Metal Film msat Microwave Frequencies)” Equation and J. Altman's “Microwave C1rcuits” No. 3 Using the information described on pages 70-71, the results obtained from the measured scattering parameters It will be done. For unbroken susceptor materials, the impedance is essentially no resistance. It is resistant. The discontinuity, or break in conductivity, creates a capacitive reactor in the impedance. Introducing the ance component.

The infrared images and temperature measurements produced by an infrared camera are captured using thermovision (The rmovision) 870 scanner (infrared camera). red The external camera is a TIG-8000 thermal image computer (Thermal Used with Image Computer). Video analysis is done by CATS software. The analysis was performed using software (version 1.04). Infrared camera, computer The computer and software will be shipped to Danderyd, Sweden. Agema Infriend Systems N.B. (Agema) Available from Infrared Systems A, B,).

Figures 5, 6, 11, 17, 18, 22, 23, and 2 The original infrared image in Figure 5 is in color. For convenience, a black and white copy is used here. Ta. The color original is not considered important here. However, the color original Attached for reference.

The preferred embodiments of the present invention have been disclosed above. The present invention provides a number of benefits other than those described above. It may also be implemented in other ways. A person skilled in the art would be able to carry out the above operation based on the above disclosures and teachings. Many modifications to the example may be possible. The scope of the invention shall be determined by the scope of the claims. should not necessarily be limited to the specific embodiments described above, depending on the interpretation Not.

Engraving (no changes to the content) Engraving (no changes to the content) horizontal position jg-6 Engraving (no changes to the content) Engraving (no changes to the content) horizontal position f! 5111 Engraving (no changes to the content) Grid square size (in inches) grid size Engraving (no changes to the content) Grid square size (inches) father 145 to 10 -5F11 Engraving (no changes to the content) Distance from left edge FjgP22 sussTITuvE9 meter F′j5P27 Heisei Year Month Day Wataru Fukasawa, Commissioner of the Patent Office 1. Indication of the case 1999 Patent Application No. 506382 (PCT/US 891 02239) 3. Person who makes corrections Relationship to the case: Applicant Name: The Pillsbury Co., Ltd. 5, date of amendment order: July 1991 Monthly 30th International Search Report PCT/us　89102239

Claims (1)

[Claims] 1. A package containing a susceptor heating means selectively responsive to microwave radiation. The heating system is equipped with a susceptor that generates heat in response to microwave radiation. However, this pest will turn the surface of food placed near it brown or burr. Furthermore, the susceptor is a conductive film formed on the support. This conductive film acts to generate heat in response to microwave radiation. the conductive film further comprises a first region, the conductive film further comprising The second region and the first region are connected to the cut portion of the conductive film. and the second region is resistant to heating by microwave irradiation. In order to reduce the responsiveness of the second region, the conductive film has a discontinuous part of the conductivity. A packaging system comprising: 2. The second region of the conductive film is located near the conductivity discontinuity of the conductive film. Contains defined small discrete conductive film areas, these small discrete conductive The conductive film area improves the responsiveness of the second region to heating by microwave irradiation. The package according to claim 1, wherein the package has a dimension sufficiently small to be smaller than the first region. ging system. 3. The second region of the conductive film includes a plurality of substantially rectangular conductive film areas. These rectangular conductive film areas are located at the cut part of the conductive film. 2. A packaging system according to claim 1, wherein the packaging system is thus separated from each other. 4. The rectangular conductive film area in the second region has a length of approximately 0.625 mm. 4. The packaging system of claim 3, wherein the packaging system is less than an inch. 5. The rectangular conductive film area in the second region has a length of approximately 0.312 4. The packaging system of claim 3, wherein the packaging system is less than 5 inches. 6. The rectangular conductive film area in the second region has a length of approximately 0.156 4. The packaging system of claim 3, wherein the packaging system is less than 3 inches. 7. The rectangular conductive film area in the second region has a length of approximately 0.078 mm. 4. The packaging system of claim 3, wherein the packaging system is less than 1 inch. 8. A pad according to claim 1, wherein the conductive film is a metallized layer of aluminum. caging system. 9. The aluminum metallization layer has a resistivity of about 10 ohms/square to about 1700 ohms. 9. The packaging system of claim 8, wherein: /square. 10. The aluminum metallization layer has a resistivity of about 60 ohms/square to about 1650 ohms/square. 9. The packaging system of claim 8, wherein Ω/square. 11. The conductive film has a resistivity of about 10Ω/square to about 1700Ω/square. 3. The packaging system of claim 2, wherein the metallization layer is aluminum. 12. The conductive film has a resistivity of about 10Ω/square to about 1700Ω/square. 4. The packaging system of claim 3, wherein the metallization layer is aluminum. 13. The conductive film has a resistivity of about 0.1Ω/square to about 2000Ω/ The packaging system of claim 4, wherein the packaging system is a square aluminum metallization layer. . 14. Claim 1 wherein said aluminum metal layer has a resistivity greater than about 60 ohms/square. 3. The packaging system described in 3. 15. The conductive film has a resistivity of about 10Ω/square to about 1700Ω/square. 6. The packaging system of claim 5, wherein the first metal layer is aluminum. 16. The aluminum metal layer has a resistivity of about 10Ω/square to about 1700Ω 16. The packaging system of claim 15, wherein: /square. 17. The aluminum metal layer has a resistivity of about 60Ω/square to about 1650Ω 16. The packaging system of claim 15, wherein: /square. 18. The conductive film has a resistivity of about 10Ω/square to about 1700Ω/square. 7. The packaging system of claim 6, wherein the first metal layer is aluminum. 19. The conductive film has a resistivity of about 10Ω/square to about 1700Ω/square. 8. The packaging system of claim 7, wherein the first metal layer is aluminum. 20. In a susceptor with variable response to heating from microwave radiation , (a) comprising a support; (b) a metallized layer formed on the support, the metallized layer comprising: (1) a first region that works to generate heat in response to microwave radiation; and (2) a micro A second region that works to generate heat in response to wave radiation, and is Make the metallization layer conductive before microwave irradiation to reduce the responsiveness of this second region. (c) the susceptor has a second region in which a discontinuous portion is formed; Constructed to selectively heat the surface of food placed close to it during microwave irradiation. A sasebuta characterized by what has been accomplished. 21. Claim that the second region has lower responsiveness to microwave radiation than the first region. The sage pig according to item 20. 22. Furthermore, (3) a third region of the metallization layer that reduces responsiveness to microwave radiation; The third region where a conductivity discontinuity is formed in the metallization layer before microwave irradiation as shown in FIG. The susceptor according to claim 20, comprising: 23. Claim that the third region has lower responsiveness to microwave radiation than the second region. The sage pig according to item 22. 24. The conductivity discontinuity portions of the metallized layer provided in the third region each have a surface area defining a plurality of third sub-regions having a conductive layer of metallization provided in the second region; the electrical conductivity break defines a plurality of second sub-regions each having a surface area; and The surface area of each third sub-region is smaller than the surface area of each second sub-region. The succulent pig according to claim 22. 25. A method to reduce the responsiveness of one area of a susceptor to microwave heating Leave it behind. The responsiveness of the first region of the thin film metallized susceptor to the heating action of microwave radiation is A thin metalized film of the susceptor is electrically connected to the first area before microwave cooking. By breaking the connections, the second region of the thin film metallized susceptor is reduced. A method characterized by: 26. The above separation involves cutting the thin metallized film of the susceptor in the first region. 26. The method of claim 25. 27. The dimensions of the continuous metallized film area in the second region are the same as in the first region. The thin metalized film of the susceptor should be larger than the dimensions of the continuous metalized film. 27. The method of claim 26, including scoring the second region of the film. 28. The above-mentioned separation is performed by continuously cutting the thin metallized film of the susceptor in the first region. separating the metallized film into a plurality of separate sub-regions of the first region; so that the surface area of each sub-region is smaller than the surface area of the second region. 26. The method according to claim 25. 29. How to make regions of the susceptor selectively respond to microwave heating In law, Continuity of the thin metallized film of the susceptor in the above areas before microwave cooking in order to change the responsiveness of the above region to the heating effect of microwave radiation. A method characterized by desynchronizing a region of a successor. 30. including susceptor heating means selectively responsive to microwave radiation; In packaging systems, susceptors generate heat in response to microwave radiation. , and this successor can brown the surface of food placed near it or The susceptor generates heat when exposed to microwave radiation. Furthermore, the susceptor has a microscopic surface due to the divided part of the susceptor surface. It has regions with different responsiveness to microwave radiation, and the above-mentioned divided portion has different responsiveness to microwave radiation. A packaging system characterized in that it affects the heating response of a region stem. 31. The first area of the susceptor is a small area defined by a divided part of the susceptor surface. These small individual areas can be heated by microwave irradiation. with dimensions small enough to reduce the responsiveness of the first region relative to the second region. 31. The packaging system of claim 30. 32. The first area of the susceptor is a plurality of areas defined by the above-mentioned divided portions of the susceptor surface. 31. The package of claim 30, comprising a substantially rectangular retainer surface area of management system. 33. Has a target area that generates strong heat when exposed to microwave heating In the successor means, This susceptor surface has a susceptor surface that generates heat when exposed to microwave radiation. has two regions, namely (a) a plurality of regions defined by divisions of the susceptor surface; a directed flow region having strips of An area that seems to extend (b) heat generation compared to uncut susceptors when exposed to microwave radiation; and a target area whose action is enhanced. 34. Has a target area that generates strong heat when exposed to microwave heating In the successor means, This susceptor surface has a susceptor surface that generates heat when exposed to microwave radiation. has two regions, namely: (a) a curvature defined by a break in the susceptor surface; A directional flow region having a strip, the convoluted strip being a target region. (b) such that the cut area extends towards the area when exposed to microwave radiation; It has a target area where the exothermic effect is enhanced compared to a susceptor without A successor means characterized by. 35. Reducing the responsiveness of selected areas of the susceptor to microwave heating In the method, Significant capacitive components additional to the susceptor impedance in the selected region above. The surface of the susceptor in the selected area is divided sufficiently to introduce the It is smaller than the total area of the susceptor surface and has a high resistance to the heating effect of microwave radiation. A method characterized by creating divided regions with reduced responsiveness. 36. Has multiple regions, with one region having low responsiveness to microwave heating In a susceptor that has been made to a first region of the surface; a second region of the susceptor surface having a divided susceptor surface; has a significant capacitive component in addition to the susceptor impedance; The second region is characterized by low responsiveness to the heating action of microwave radiation. A saseibuta.