Repulpable and recyclable composite packaging articles and related methods
A reusable, fiber containing pulp product is described that is highly suited for use in the manufacture of paper products. The reusable, fiber containing pulp product provides a mixture of fibers and small, dense polymer/particle fragments. The polymer/particle fragments within the reusable, fiber containing pulp product have a size range and density that facilitates efficient removal of the polymer/particle fragments using pressure screens.
1. A method of manufacturing a heat sealable and recyclable packaging structure, the method comprising:
extrusion coating of a plurality of released fibers with a plurality of polymer/particle fragments that during recycling comprise a thermoplastic resin and a plurality of mineral particles;
wherein said plurality of polymer/particle fragments have a mean surface area in the range of 0.0005 mm 2 to 2 mm 2 and a density in the range of 1.01 g/cm 3 to 4.75 g/cm 3 ;
wherein said plurality of mineral particles comprise (i) a plurality of mineral nano-particles that are 100 nanometers or less in size and (ii) a plurality of ultrafine mineral nano-particles ranging from 0.06 microns to 0.10 microns in size;
wherein said extrusion coating process is carried out under the following conditions:
said thermoplastic resin having a melt flow index in the range of 4.0 g/10 min to 16 g/10 min;
a melt temperature of 590° F.±20%;
an extruder screw or tube barrel pressure in the range of 1,200 psi to 2,500 psi;
an extruder screw or tube barrel air gap in the range of 4 inches to 16 inches;
extruder screw or tube barrel die gap in the range of 0.020 inches to 0.050 inches;
a barrel temperature in the range of 400° F. to 640° F.; and
an extrusion lamination line speed from 100 PPM to 3,500 PPM.
2. The method of claim 1 , wherein said plurality of mineral nano-particles are selected from the group of minerals consisting of: wollastonite (hydrated and non-hydrated); magnesium silicate; barium sulfate; barium ferrite; magnesium hydroxide; magnesium carbonate; aluminum trihydroxide; magnesium carbonate; natural silica or sand; cristobalite; diatomite; novaculite; quartz tripoli clay calcined; muscovite; nepheline-syenite; feldspar; calcium sulfate-gypsum; terra alba; selenite; domite; silicon mica; hydrated aluminum silicates; coke; montmorillonite (MMT); attapulgite (AT) carbon black; pecan nut flour; cellulose particles; wood flour; fly ash; starch; titanium dioxide (Ti02); barium carbonate; terra alba; selenite; nepheline-syenite; muscovite; pectolite; chrysotile; borates; sulfates; and precipitated and ground calcium carbonate.
3. The method of claim 1 , wherein said plurality of mineral nano-particles are one or more of: wollastonite (hydrated and non-hydrated); magnesium silicate; barium sulfate; barium ferrite; magnesium hydroxide; magnesium carbonate; aluminum trihydroxide; magnesium carbonate; natural silica or sand; cristobalite; diatomite; novaculite; quartz tripoli clay calcined; muscovite; nepheline-syenite; feldspar; calcium sulfate-gypsum; terra alba; selenite; domite; silicon mica; hydrated aluminum silicates; coke; montmorillonite (MMT); attapulgite (AT) carbon black; pecan nut flour; cellulose particles; wood flour; fly ash; starch; titanium dioxide (Ti02); barium carbonate; terra alba; selenite; nepheline-syenite; muscovite; pectolite; chrysotile; borates; sulfates; precipitated and ground calcium carbonate; and combinations thereof.
4. The method of claim 1 , wherein said plurality of ultrafine mineral nano-particles are selected from the group of minerals consisting of: wollastonite (hydrated and non-hydrated); magnesium silicate; barium sulfate; barium ferrite; magnesium hydroxide; magnesium carbonate; aluminum trihydroxide; magnesium carbonate; natural silica or sand; cristobalite; diatomite; novaculite; quartz tripoli clay calcined; muscovite; nepheline-syenite; feldspar; calcium sulfate-gypsum; terra alba; selenite; domite; silicon mica; hydrated aluminum silicates; coke; montmorillonite (MMT); attapulgite (AT) carbon black; pecan nut flour; cellulose particles; wood flour; fly ash; starch; titanium dioxide (Ti02); barium carbonate; terra alba; selenite; nepheline-syenite; muscovite; pectolite; chrysotile; borates; sulfates; and precipitated and ground calcium carbonate.
5. The method of claim 1 , wherein said plurality of ultrafine mineral nano-particles are one or more of: wollastonite (hydrated and non-hydrated); magnesium silicate; barium sulfate; barium ferrite; magnesium hydroxide; magnesium carbonate; aluminum trihydroxide; magnesium carbonate; natural silica or sand; cristobalite; diatomite; novaculite; quartz tripoli clay calcined; muscovite; nepheline-syenite; feldspar; calcium sulfate-gypsum; terra alba; selenite; domite; silicon mica; hydrated aluminum silicates; coke; montmorillonite (MMT); attapulgite (AT) carbon black; pecan nut flour; cellulose particles; wood flour; fly ash; starch; titanium dioxide (Ti02); barium carbonate; terra alba; selenite; nepheline-syenite; muscovite; pectolite; chrysotile; borates; sulfates; precipitated and ground calcium carbonate; and combinations thereof.
6. The method of claim 1 , wherein said plurality of mineral particles have a hardness of between 2.0 to 4.0 Mohs.
7. The method of claim 1 , wherein said plurality of mineral particles are selected from the group of minerals consisting of clay and silica.
8. The method of claim 1 , wherein said plurality of mineral particles are one or more of clay and silica.
9. The method of claim 1 , wherein said plurality of mineral particles are clay.
10. The method of claim 1 , wherein said plurality of mineral particles are silica.
11. The method of claim 1 , wherein said plurality of released fibers comprise reusable fibers containing pulp that is suitable for manufacture of new paper products.
12. The method of claim 1 , wherein said plurality of released fibers comprise one or more of softwood fibers, hardwood fibers, and combinations thereof.
13. The method of claim 1 , wherein said plurality of released fibers comprise a mixture of softwood fibers and hardwood fibers.
14. The method of claim 9 , wherein said mixture of softwood and hardwood fibers comprises from 5% to 95% softwood fibers.
15. The method of claim 9 , wherein said mixture of softwood and hardwood fibers comprises from 25% to 90% softwood fibers.
16. The method of claim 9 , wherein said mixture of softwood and hardwood fibers comprises from 5% to 95% hardwood fibers.
17. The method of claim 9 , wherein said mixture of softwood and hardwood fibers comprises from 25% to 90% hardwood fibers.
18. The method of claim 1 , wherein said plurality of released fibers are derived from a paper having a basis weight of in the range of 30 lbs/3000 sq. ft. to 200 lbs/3000 sq. ft. and a thickness in the range of 0.010 inches to 0.036 inches.
19. The method of claim 1 , wherein the plurality of polymer/particle fragments are dimensioned to pass through a 0.005 inch slotted pressure screens.
20. The method of claim 1 , wherein the plurality of polymer/particle fragments are dimensioned to pass through a 0.005 inch round hole.
21. The method of claim 1 , wherein said plurality of polymer/particle fragments is supplied to the extrusion process in the form of pellets.
22. The method of claim 1 , wherein said plurality of polymer/particle fragments have coat weights from 4 lbs/3 MSF to 30 lbs/3 MSF.
23. The method of claim 1 , wherein said heat sealable and recyclable packaging structure does not contain water-based dispersions, aqueous dispersions, aqueous coatings, emulsions, emulsion-containing coatings, water-containing dispersions, and press-line applications.
24. The method of claim 1 , wherein said plurality of polymer/particle fragments after said extrusion coating step form a mineral containing layer that (i) weighs from 15 g/m2 to 50 g/m2, (ii) is coextruded in line on an extrusion coating machine, and (iii) is bonded by extrusion to said plurality of released fibers.
25. The method of claim 24 , wherein the mineral containing layer is from 25% to 75% amorphous has a water vapor transmission rate (WVTR), under conditions of 100° F. and 90% relative humidity, from 7.13 g/m 2 per day to 22 g/m 2 per day, as determined using Test Method T-464.
26. The method of claim 1 , wherein said a plurality of polymer/particle form a barrier layer;
wherein said barrier layer comprises one to six coextruded non-interspersed layers, each of said one to six coextruded non-interspersed layers is between 0% to 70% by weight mineral particles that are dispersed in a thermoplastic bonding agent; and
wherein said barrier layer has a basis weight in the range of 6 g/m 2 (4 lbs/3 msf) to 98 g/m 2 (60 lbs/3 msf), and a caliper (thickness) in the range of 0.3 millimeters to 3.0 millimeters.
27. The method of claim 1 , wherein mineral particles are evenly dispersed in said thermoplastic bonding agent.