There are many types of ovens on the market, but self-cleaning and continuous cleaning varieties are the most popular. Melted plastic in the bottom of your oven from melted dishes or cellophane is difficult to remove. The removal method is the same for self-cleaning or continuous cleaning ovens, and requires a good bit of elbow grease.
Heat the oven to its lowest setting until the plastic is pliable.
Put on oven gloves or rubber gloves to protect your hands from being burnt.
Use a heat-resistant spoon to lift the bottom heating rack up off the floor of the oven.
Scrape off the plastic with a wooden spatula or spoon. Wipe the melted plastic off the spoon with a hot cloth.
Wipe out the oven with a clean, damp cloth.