Two-piece pleated foam cup
AssigneeMaryland Cup Corporation
InventorDavid H. Herbst
Life of this patent
Estimating the term…
Abstract
A two-piece foam plastic cup is made from a rectangular blank and either a bottom disc or expandible plastic foam beads. The rectangular blank is pleated in triangular transverse pleats having their apices adjacent to the top rim or mouth of the finished cup to form a frusto-conical sidewall blank with a lapped side seam portion. This sidewall blank is placed in a heated mold with either foam plastic beads or a bottom disc and the mold is heated to fuse the pleats, fuse the lapped side seam, and expand the bottom material and sidewall material into a fused unitary cup or container structure having a sidewall of uniform thickness but with visible pleats therein, despite its resulting smooth surface.
Claims18
In a container, a frustoconical sidewall structure comprising:
- an arcuate blank formed from an initially rectangular blank of foam plastic sheet material;
- said initially rectangular blank being provided with a plurality of pairs of divergent pleat lines defined in the surface and across the width dimension thereof, a corresponding line of each pair being overlapped with the other line of that pair to form a multi-layered triangular area for each said pair of pleat lines extending from a top portion to a bottom portion of said sidewall structure, thereby constraining said initially rectangular blank to assume an arcuate shape defining said arcuate blank;
- said arcuate blank having opposing ends across the width thereof;
- and
- said opposing ends being overlapped and heat sealed together to form said frustoconical sidewall and provide a side seam for same.
In a container, a frustoconical sidewall structure comprising:
- an arcuate blank formed from an initially rectangular blank of foam plastic sheet material;
- said initially rectangular blank being provided with a plurality of pairs of divergent pleat lines defined in the surface of said blank across the width dimension thereof, a corresponding line of each pair being overlapped with the other line of that pair to form a multi-layered triangular area for each said pair of pleat lines and said pleat lines in each pair diverging from a top portion of said sidewall structure thereby constraining said initially rectangular blank to assume an arcuate shape defining said arcuate blank;
- the layers overlapped in each of said multi-layered triangular areas being bonded together in said sidewall structure to provide a unitary structure;
- said arcuate blank having opposing ends across the width thereof;
- and
- said opposing ends being overlapped and heat-sealed together to form said frustoconical sidewall structure and provide a side seam for same.
A container made by the method comprising the steps of:
- providing a rectangular blank of plastic foam sheet material;
- forming a plurality of pairs of divergent pleat lines across the width dimension of said blank;
- overlapping one pleat line with the other to form triangular double layers in said blank, thereby constraining said blank to assume an arcuate shape;
- overlapping the opposite edges of said blank in a side seam configuration to form a multi-sided, substantially frusto-conical cup sidewall assembly;
- placing said sidewall assembly in a conforming mold means;
- providing a bottom blank in said mold means at one end of said sidewall assembly;
- and
- applying heat thereto to fuse said overlapping areas and heat seal said side seal configuration and said bottom blank to said sidewall assembly to provide a unitary cup structure.
A frustoconical sidewall structure made by the following method of forming a hollow frustoconical foam plastic structure from a rectangular blank of foam plastic sheet material comprising:
- forming a plurality of pairs of divergent pleat lines across the width dimension of said blank;
- overlapping one pleat line with the other to form triangular double layers in said blank, thereby constraining said blank to assume an arcuate shape;
- overlapping the opposite edges of said blank in a side seam configuration;
- and
- pressing and heat sealing said side seam and said triangular double layers to provide a frustoconical hollow structure.
Dependencies are inferred from the claim text.