Method and apparatus for producing labeled, plastic foam containers, and product of same

Abstract

A method and apparatus for producing labeled, plastic foam containers, such as a labeled EPS cup uses a heated pocket to thermally bond a label to a plastic cup. Also described is a labeled plastic foam container, such as a labeled EPS cup, having high quality printing capabilities, sufficient stiffness, acceptable insulation and barrier properties and reduced production cost.

1 . A method for labeling a plastic foam container comprising: 
 automatically positioning an unlabeled, preformed plastic foam container onto a mandrel at a first station;    applying a label to an exterior surface of the plastic foam container at a second station;    directly heating a work piece that defines a cavity that corresponds substantially in shape to the outer surface of the plastic foam container;    positioning the work piece so that the cavity substantially surrounds the exterior surface of said plastic foam container to which the label is applied at a third station;    directly heating the exterior surface of the plastic foam container to which the label is applied with said cavity as the plastic foam container is disposed within the cavity, at a temperature and a time sufficient to bond the label to exterior surface of the container to provide a resulting labeled, plastic foam container; and    removing the resulting labeled, plastic foam container from the mandrel.    
     
     
         2 . The method of  claim 1 , wherein automatically positioning an unlabeled, preformed plastic foam container includes automatically loading said unlabeled, preformed plastic foam containers with an indexing turrent.  
     
     
         3 . The method of  claim 1 , wherein the cavity is heated to a temperature in a range of about 135° C. to about 150° C.  
     
     
         4 . The method of  claim 1 , wherein the cavity is heated with heating elements that are in thermal contact with the surface of the cavity.  
     
     
         5 . The method of  claim 1 , wherein the cavity is heated by applying steam to the cavity.  
     
     
         6 . The method of  claim 1 , further comprising applying pressure to the exterior surface to which the label is applied with the cavity.  
     
     
         7 . The method of  claim 1 , wherein the work piece comprises a metal cylinder that is positioned to move relative to the mandrel onto which the cup is positioned.  
     
     
         8 . The method of claim I, wherein the mandrel is provided on a rotating turret that moves the mandrel successively to the first station at which the plastic foam container is placed on the mandrel, the second station at which the label is applied to the plastic foam container, and the third station at which the cavity is positioned to surround exterior surface of the plastic foam container to which the label is applied.  
     
     
         9 . The method of  claim 8 , wherein the work piece comprises a metal cylinder that is positioned at the third station to move relative to the mandrel onto which the plastic foam container is positioned.  
     
     
         10 . The method of  claim 1 , wherein the label is affixed to said plastic foam container with at least one of a thermal agent, a hot melt, or a plastic coating.  
     
     
         11 . The method of  claim 10 , wherein the plastic coating comprises at least one of polyethylene or polypropylene.  
     
     
         12 . The method of  claim 1 , wherein the plastic foam container, prior to application of the label, has a density of less than 0.8 g/cm 3 .  
     
     
         13 . The method of  claim 12 , wherein the plastic foam container, prior to application of the label, has a density in the range of about 0.041 to 0.076 g/cm 3 .  
     
     
         14 . The method of  claim 12 , wherein the resulting labeled, plastic foam container has an overall density in the range of 0.05720-0.1888 g/cm 3 .  
     
     
         15 . The method of  claim 1 , wherein the label comprises at least one of paper, aluminum or plastic film.  
     
     
         16 . The method of  claim 1 , wherein said plastic foam container is a cup.  
     
     
         17 . The method of  claim 16 , wherein the plastic foam cup comprises EPS.  
     
     
         18 . A labeled, plastic foam container manufactured according to the method of  claim 1 .  
     
     
         19 . An apparatus for labeling a plastic foam container comprising: 
 means for automatically positioning a preformed plastic foam container onto a mandrel at a first station;    means for applying a label to an exterior surface of the plastic foam container at a second station;    a work piece that defines a cavity, said work piece being movable relative to the mandrel at a third station so that the cavity substantially surrounds and heats the plastic foam container at the exterior surface to which the label is applied, wherein said work piece is configured to be directly heated to a temperature sufficient to bond the label to exterior surface of the container to provide a resulting labeled, plastic foam container; and    means for removing the resulting labeled, plastic foam container from the mandrel.    
     
     
         20 . The method of  claim 1 , wherein the means for automatically positioning an unlabeled, preformed plastic foam container includes an indexing turret configured to automatically load said unlabeled, preformed plastic foam containers at the first station.  
     
     
         21 . The apparatus of  claim 19 , wherein the work piece comprises a metal cylinder that is adapted to move relative to the mandrel onto which the container is positioned when the mandrel is at the third station.  
     
     
         22 . A machine for labeling plastic, foam containers comprising: 
 a rotatable turret having a plurality of mandrels attached thereto, the turret being driven to rotate the mandrills to a plurality of stations, wherein the mandrels are configured to receive a plastic foam container;    a container feeder provided at a first station to feed an unlabeled, preformed plastic foam container onto a mandrel,    a sleeve transfer device provided at a second station being configured to wrap and affix a label to a plastic foam container on one of the mandrels; and    a work piece defining a cavity provided at a third station, the cavity being configured to be positioned over the outer surface of a plastic foam container on one of the mandrels, so as to substantially surround the exterior surface to which the label is applied, wherein the cavity is configured to be directly heated to a temperature sufficient to bond the label to the plastic foam container.    
     
     
         23 . The machine of  claim 22 , wherein the cavity is heated to a temperature in a range of about 135° C. to about 150° C.  
     
     
         24 . The machine of  claim 22 , wherein the cavity is heated with heating elements that are in thermal contact with the surface of the cavity.  
     
     
         25 . The machine of  claim 22 , wherein the cavity is heated by applying steam to the cavity.  
     
     
         26 . The machine of  claim 22 , wherein the cavity is configured to apply pressure to the exterior surface to which the outer surface of a plastic foam container on one of the mandrels.  
     
     
         27 . The machine of  claim 22 , wherein the cavity is formed within a metal cylinder that is positioned to move relative to the turret.  
     
     
         28 . A labeled plastic foam container comprising: 
 an inner plastic foam portion having a density of less than 0.8 g/cm 3 ;    an outer sleeve that adheres to an outer surface of said inner plastic foam portion, the outer sleeve having an outwardly facing surface to which is applied print or graphical designs, the outer sleeve providing stiffness to the inner portion.    
     
     
         29 . The labeled plastic foam container, wherein the resulting labeled, plastic foam container has an overall density in the range of 0.05720-0.1888 g/cm 3 .  
     
     
         30 . The labeled plastic foam container, wherein the inner plastic foam portion defines a cup shape with a lip portion, bottom portion, and sidewall.  
     
     
         31 . The labeled plastic foam container according to  claim 30 , wherein the inner plastic foam portion comprises EPS.  
     
     
         32 . The labeled plastic foam container according to  claim 28 , wherein the outer sleeve comprises one of a metal foil, a plastic film or a paper sleeve.