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 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 bonding agent, wherein the mineral-containing resin has a density of 1.01 g/cm3 to 4.90 g/cm3 and a mineral content of 20% to 70%, the extrusion coating providing a moisture barrier having Tappi T464 moisture barrier values from about 0.46 g/100 in2 to about 37.7 g/100 in2; wherein the extrusion process is carried out under the following conditions: the resin having a melt flow index from 4 g/10 min. to 16 g/10 min.; a melt temperature from 440° F. to 640° F.; an extruder screw or tube barrel pressure from 1,200 psi to 2,500 psi; an air gap from 4″ to 16″; a die gap from 0.020″ to 0.050″; barrel and die zone temperatures from 400° F. to 640° F.; an extrusion line speed from 100 FPM to 3,500 FPM; and an extrusion lamination line speed from 100 FPM to 3,500 FPM.