If your Tupperware lid has become bent or deformed after being heated in the microwave, it is likely that the heat caused the plastic to soften and lose its original shape. While it may not be possible to completely restore the lid to its exact original form, you can try the following steps to help reshape it:
Allow it to cool down: Let the Tupperware and the lid cool down completely to room temperature. This will allow the plastic to harden again.
Gentle pressure: Use your hands to apply gentle pressure to the areas that are bent inward. Slowly try to reshape the lid by applying gentle force to push it back into its original shape. Be careful not to use excessive force or bend it too far, as it may cause further damage or breakage.
Warm water method: Alternatively, you can try the warm water method. Submerge the lid in a bowl of warm water (not boiling hot) for a few minutes. The warmth may help soften the plastic slightly, making it more pliable. Once it's warmed up, remove it from the water and reshape it using gentle pressure with your hands. Remember not to use hot or boiling water, as it can damage the plastic or cause it to warp further.
Cooling and setting: After you've reshaped the lid, allow it to cool and set in its new shape. You can place it on a flat surface or use a weighted object to keep it in position while it cools down and hardens.
It's important to note that the success of these methods may vary depending on the extent of the deformation and the specific properties of the plastic used in your Tupperware. If the lid remains deformed despite your attempts, it may be necessary to replace it with a new one. Additionally, always follow the manufacturer's instructions regarding microwave use and avoid heating plastics that are not microwave-safe to prevent any potential hazards.