Recycling of barrier polystyrene foam scrap and barrier polystyrene foam containing recycled barrier polystyrene foam scrap
OwnerGerald G. Gusavage, Thomas A. Hessen +3inventors
InventorsGerald G. Gusavage, Thomas A. Hessen, Thomas R. Hardy, Henry G. Schirmer, Susan R. Flye
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Abstract
A barrier foam tray contains recycled reclaim of barrier foam. The tray comprises a sheet of foamed polystyrene (PS) having laminated to it a flexible barrier film. The foamed polystyrene part can have admixed therein from 0.0001% up to 30% by weight of the flexible barrier film. The barrier film contains a barrier polymer such as ethylene vinyl alcohol copolymer (EVOH). The tray is made by grinding laminate scrap and extruding reclaim therefrom with virgin polystyrene.
Claims3
A method to recycle thermoformable barrier sheet comprising:
- (a) extruding and foaming polymer pellets thereby making a first sheet of foamed polymer having two opposing surfaces;
- (b) laminating onto at least one said surface of said first foamed sheet a flexible barrier film, said flexible barrier film having a barrier layer containing a barrier polymer selected from ethylene vinyl alcohol copolymer, acrylonitrile copolymer, amorphous nylon copolymer, or mixtures thereof, and a bonding layer, whereby the bonding layer is adhered to the one said surface of said foamed polymer sheet thereby making a laminate;
- (c) thermoforming the resultant laminate where steps (b) and (c) generate scrap of laminate;
- (d) making reclaim pellets by grinding and pelletizing the scrap;
- (e) extruding and foaming more of said polymer pellets together with from about 0.001% up to about 100% by weight of the reclaim pellets of scrap, thereby making a second sheet of foamed polymer having two opposing surfaces;
- and
- (f) laminating onto at least one said surface of said second foamed sheet a flexible barrier film;
- whereby said second foamed sheet contains on a weight basis from about 0.0001% up to about 30% flexible barrier film and wherein said foaming steps comprise injecting 100% carbon dioxide as a blowing agent.
A method for making a foamed article with barrier properties, comprising:
- providing polymer pellets;
- heating said pellets to produce a polymer melt;
- injecting a blowing agent into said melt;
- extruding said blowing agent-containing melt into a sheet;
- laminating a barrier film onto said sheet;
- thermoforming the laminated sheet into a plurality of articles;
- trimming the excess, non-formed laminated sheet thereby forming scrap;
- pelletizing said scrap;
- and
- introducing said scrap into said polymer pellets.
Dependencies are inferred from the claim text.