The present invention relates to plastic plates, and, more particularly, to molded plastic plates that are intended to be used and then disposed of. Such plates are often used at buffets or picnics and the like, or for meals where a large number of people make it impractical to use non-disposable plates. Typically, the plates are stacked, one on top of another, for use at such events, so that a person can select a plate and then serve himself.
Although the prior art plastic plates are useful for their intended purpose, they suffer from several disadvantages. When the plates are stacked, there is little or no clearance between the plates creating difficulty in picking up just a single plate. Often two or three plates are picked up at a time instead of one, causing excessive waste. Moreover, the edges of the plates are somewhat sharp and can cause cuts in the fingers when the plates are separated from the stack or otherwise handled.
Providing the prior art plastic plates with rim edges that are folded under, or rolled, would solve the problem of sharp plate edges. However, heretofore those working in the molded plastic plate art have not been able to manufacture plates with rolled edges. One reason is that a rolled rim cannot be molded into the plate because of the difficulty in removing the molded plate from the mold. The rolled or folded-under edge creates a double layer of plastic at the edge of the plate and the plate cannot be lifted or dropped out of the mold without disturbing one or the other layers.
Nor has it been feasible to roll or fold under the edges of pre-molded prior art plastic plates. Although various apparatuses have been used to roll the edges of pre-molded plastic cups, they have not been successfully used with plastic plates. That is because, unlike plastic cups, which have a natural separation between their rims when stacked, due to the truncated cone shape of the cup, prior art plates lie flat on top of each other with no separation therebetween, like playing cards in a deck. The lack of separation between plates prevents a positive pick-up of each individual plate by a rolling apparatus, resulting in several plates having their edges rolled together. Moreover, it is not economically feasible to introduce one plate at a time into a rolling apparatus, since that results in an excessively slow production rate, creating a product that is too expensive to make, given the relatively low cost of plastic plates to a consumer.
USPTO Backgrounds
USPTO Backgrounds