Methods, apparatus, and chemical compositions for selectively coating fiber-based food containers

1. A method of manufacturing a fiber based microwave bowl of the type including a substantially circular bottom portion bounded by an inclined circumferential side wall, the method comprising the steps of:

providing a wire mesh mold approximating the shape of the bowl;

preparing an aqueous fiber based slurry comprising up to 100% virgin fiber;

adding an embedded moisture barrier to the slurry;

immersing the mold in the slurry;

drawing a vacuum across the mold within the slurry until a desired thickness of fiber particles accumulates at a surface of the mold;

removing the accumulated particles from the mold;

drying and pressing the accumulated particles in a press to thereby form the bowl;

transferring the bowl from the press to a coating station; and

applying an acrylic based oil barrier layer to a surface of the bowl at the coating station.

2. The method of claim 1 , wherein the embedded moisture barrier comprises 2%-5% alkyl ketene dimer (AKD).

3. The method of claim 2 , wherein the oil barrier layer comprises a calcium carbonate component to facilitate bonding to a bowl surface.

4. The method of claim 2 , wherein the oil barrier layer comprises a pea emulsion.

5. The method of claim 2 , wherein the oil barrier layer comprises an alginate.

6. The method of claim 2 , wherein the oil barrier layer comprises an aqueous solution including about 25% acrylate and a first supplemental component configured to reduce tackiness.

7. The method of claim 6 , wherein the first supplemental component comprises about 1.8% rice bran wax.

8. The method of claim 7 , wherein the coating station comprises: a spray system; and a conveyor configured to move the bowl along a direction of travel into engagement with the spray system.

9. The method of claim 8 , wherein the spray system comprises a first nozzle configured to discharge a full cone spray pattern onto the bottom of the bowl.

10. The method of claim 9 , wherein the spray system comprises a second nozzle configured to discharge a hollow cone spray pattern onto an inside surface of the sidewall.

11. The method of claim 9 , wherein the solids comprise acrylate, rice bran wax, pectin, and pea protein.

12. The method of claim 6 , wherein the first supplemental component comprises about 0.4% pectin.

13. The method of claim 6 , wherein the oil barrier layer comprises a second supplemental component configured to facilitate emulsion of the first supplemental component.

14. The method of claim 13 , wherein the second supplemental component comprises about 0.3% pea protein.

15. The method of claim 6 , wherein the oil barrier layer comprises a third supplemental component configured to adjust the PH level of the oil barrier coating to thereby facilitate acrylate curing.

16. The method of claim 15 , wherein the third supplemental component comprises about 0.2% liquid ammonium.

17. The method of claim 1 , wherein the oil barrier layer comprises an approximately 1:3 solution of acrylic and water.