To address the multi-stage heating requirements, the structural optimization of microwave oven baking trays needs to consider aspects such as material selection, shape design, heat conduction path, energy distribution control, edge treatment, dynamic adaptability, and safety protection, in order to achieve uniform heating and efficient cooking of food at different heating stages.
Material selection is fundamental to optimizing the structure of microwave oven baking trays. Traditional microwave oven baking trays often use single metal or ceramic materials. However, metals easily reflect microwaves, leading to uneven heating, while ceramics may affect efficiency due to low thermal conductivity. Modern designs often use composite materials, such as embedding microwave-absorbing particles in a ceramic substrate, or using multi-layer structures (such as metal-ceramic composite layers) to balance microwave penetration and thermal conductivity. This design allows the microwave oven baking tray to quickly absorb microwave energy and convert it into heat energy in the initial heating stage, while slowly releasing heat through the ceramic layer in the subsequent heat preservation stage, avoiding localized overheating.
Shape design directly affects the uniformity of energy distribution. Traditional rectangular microwave oven baking trays are prone to heat accumulation at the corners, resulting in burnt edges and uncooked centers. Optimization schemes can employ rounded rectangular or elliptical structures, reducing microwave reflection concentration by minimizing right angles at the corners. For example, the larger the radius of curvature at the corners of a rounded rectangular microwave oven baking tray, the more dispersed the microwave reflection at the edges, resulting in a more uniform heat distribution. Furthermore, a slightly curved or wavy bottom design of the microwave oven baking tray increases the contact area with food, promoting heat convection, especially suitable for heating liquid foods.
Optimizing the heat conduction path is crucial. Multi-stage heating requires the microwave oven baking tray to provide differentiated heat conduction efficiency at different stages. For example, during the defrosting stage, the microwave oven baking tray needs to quickly transfer microwave energy to the interior of the food; while during the baking stage, it needs to minimize heat loss to maintain surface crispness. To this end, heat-conducting grooves or raised structures can be incorporated into the bottom of the microwave oven baking tray, adjusting the heat conduction rate by changing the contact area. Heat-conducting grooves increase airflow and reduce heat accumulation at the bottom, suitable for thin slices of food; raised structures directly contact the bottom of the food, improving heat conduction efficiency, suitable for thicker ingredients such as meats.
Energy distribution control needs to be combined with microwave field characteristics. Uneven microwave field distribution within a microwave oven is the primary cause of heating differences. Optimizing the microwave oven baking tray structure can be achieved by introducing a microwave stirrer or pattern stirrer design, such as adding metal blades or grooves to the edges. This utilizes the interaction between microwaves and metal to alter the field distribution. When microwaves irradiate the metal blades, they excite secondary radiation, creating a new microwave field distribution pattern that compensates for weak areas in the original field. Furthermore, the surface of the microwave oven baking tray can be designed with a micro-textured structure (such as honeycomb or striped patterns) to reduce localized energy concentration by scattering microwaves.
Edge treatment is crucial to preventing heat buildup. Traditional microwave oven baking trays tend to form high-temperature zones at the edges due to microwave reflection. Optimization can employ a gradually thinning design, where the edges gradually thin to reduce the microwave reflection cross-sectional area. For example, the thickness of the microwave oven baking tray's edge gradually decreases from the center outwards, reducing the intensity of microwave reflection at the edges and resulting in more even heat distribution. Additionally, airflow channels or ventilation holes can be incorporated into the edges to remove excess heat through air convection, preventing localized overheating.
Dynamic adaptability must consider the heating requirements of different foods. Multi-stage heating often involves different phases such as defrosting, baking, and keeping warm, requiring the microwave oven baking tray to have an adaptive structure. For example, a deformable design can be used, allowing for folding or combination to switch between different shapes: unfolding into a flat surface to increase contact area during defrosting, and folding into a three-dimensional structure to concentrate heat during baking. Furthermore, the microwave oven baking tray can be equipped with removable dividers, allowing adjustment of the divider position to control the contact distance between food and microwaves, accommodating the heating needs of ingredients of varying thicknesses.
Safety is a necessary guarantee for optimized design. Multi-stage heating may involve high temperatures or prolonged use, requiring the microwave oven baking tray to possess characteristics such as high-temperature resistance and explosion-proof properties. For example, using high-strength ceramic or explosion-proof glass materials, or applying a non-stick coating to the surface of the metal microwave oven baking tray, can prevent food from sticking and causing localized overheating. In addition, the edges of the microwave oven baking tray should be rounded to prevent scratching the microwave oven's inner wall or the user's fingers, improving safety.
