REPULPABLE AND RECYCLABLE COMPOSITE PACKAGING ARTICLES AND RELATED METHODS

摘要

Unexpectedly unique and environmentally friendly composite material structures, storage articles fabricated therefrom, and related methods. The composite structure includes at least one or more fiber-containing layers, such as fiberboard or other layers having fibers from natural and/or synthetic sources, and one or more mineral-containing layers. The mineral-containing layer(s) comprises a thermoplastic bonding agent fixing the mineral particles in place. The fiber-containing layer(s) and mineral-containing layer(s) can be shaped, sized, and manufactured such that the composite structure formed therefrom is capable of being machined to form the storage article. The composite structure can be repulped and recycled without the use of dispersions, emulsions, or aqueous solutions. Further, the composite reduces layer mass requirements for heat seal, barrier, and fiber adhesion compared to polymer layers. The composite structure further has tensile strength and other structural characteristics that allow it to be readily machined into desired storage article forms.

主权项

1. A method of making a recyclable composite packaging structure including a fiber-containing layer and a mineral-containing layer, the method comprising:
extrusion coating the mineral-containing layer onto the fiber-containing layer using a mineral-containing resin having mineral particles interspersed within a polyolefin bonding agent; wherein the extrusion process is carried out under the following conditions:
the resin having a melt flow index from about 4 g/10 min. to about 16 g/10 min.;a melt temperature from about 440° F. to about 640° F.;an extruder screw or tube barrel pressure from about 1,200 psi to about 2,500 psi;an air gap from about 4″ to about 16″;a die gap from about 0.020″ to about 0.050″;barrel and die zone temperatures from about 400° F. to about 640° F.;an extrusion line speed from about 100 FPM to about 3,500 FPM; andan extrusion lamination line speed from about 100 FPM to about 3,500 FPM.