Rolled edge trays having smooth edges and stacking extensions
AssigneeConverter Manufacturing, LLC
InventorMillard F Wallace
Life of this patent
Estimating the term…
Abstract
The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling.
Claims20
A tray for containing a food, the tray
- being formed from a sheet of thermoformable plastic having a peripheral edge and
- having a shape that includes
- a concave, rounded rectangular tray-shaped body and
- a rim connected to the body about its entire periphery, the rim including an extension interposed between the body and a smooth, rolled-over edge wherein the peripheral edge of the sheet is disposed away from the periphery of the tray, the rolled-over edge including a stacking extension at each corner of the rim,
- wherein a plurality of the tray are stackable in a nested conformation such that when a first tray is nested within a second tray, the rolled-over edge of the first tray contacts the rim of the second tray only at one or more of the stacking extensions.
Dependencies are inferred from the claim text.