Non-uniformly perforated plastic bag

1. A perforated plastic bag wherein the volume of said bag is 100 liters or more;

wherein the average perforation diameter is 500 micrometers or less;

wherein said plastic bag comprises a lower zone and a top zone,

wherein the perforation density of said lower zone is greater than the perforation density of said top zone.

2. The plastic bag of claim 1 , wherein the ratio of said perforation density of said lower zone to said perforation density of said top zone is 1.1:1 or higher.

3. The plastic bag of claim 1 , wherein the average perforation diameter is 15 micrometers or more.

4. The plastic bag of claim 1 , wherein the plastic bag comprises a polymeric film.

5. The plastic bag of claim 4 , wherein the polymeric film has an average thickness of 5 micrometers or more.

6. The plastic bag of claim 5 , wherein the polymeric film has an average thickness of 200 micrometers or less.

7. The plastic bag of claim 4 , wherein the polymeric film comprises a polyolefin, a polyvinyl, a polystyrene, a polydiene, a polysiloxane, a polyamide, a vinylidene chloride polymer, a vinyl chloride polymer, a copolymer thereof, a blend thereof, or a lamination thereof.

8. The plastic bag of claim 7 , wherein the polyolefin comprises a polyethylene, a polypropylene, a copolymer thereof, a blend thereof, or a lamination thereof.

9. The plastic bag of claim 8 , wherein the polyethylene is a low density polyethylene, an ultralow density polyethylene, a linear low density polyethylene, a metallocene-catalyzed polyethylene, a copolymer of ethylene with a polar monomer, a medium density polyethylene, a high density polyethylene, a copolymer thereof, or a blend thereof.

10. The plastic bag of claim 9 , wherein the polar monomer of the copolymer of ethylene with the polar monomer is vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid, methacrylic acid, or a mixture thereof.

11. The plastic bag of claim 4 , wherein the polymeric film has an inherent oxygen permeability coefficient of 2,000 cm 3 0C mil/(m 2 day) or higher.

12. The plastic bag of claim 4 , wherein the polymeric film has an inherent oxygen permeability coefficient 50,000 cm 3 0C mil/(m 2 day) or lower.

13. The plastic bag of claim 4 , wherein the polymeric film has an inherent carbon dioxide permeability coefficient of 10,000 cm 3 0C mil/(m 2 day) to 60,000 cm 3 0C mil/(m 2 day).

14. The plastic bag of claim 1 , wherein the perforation density of the top zone is 2 mm 2 of perforation per m 2 of a surface area of the bag or higher.

15. The plastic bag of claim 14 , wherein the perforation density of the top zone is 12 mm 2 of perforation per m 2 of the surface area of the bag or lower.

16. The plastic bag of claim 1 , wherein the plastic bag is generally rectangular and has a first short side and a second short side, wherein the first short side forms a top of the bag and is formed to include an opening that opens into the plastic bag and the second short side forms a bottom of the bag.

17. The plastic bag of claim 16 , wherein the top zone is a rectangular region formed by an imaginary line that is generally parallel to the top of the bag and the bottom of the bag.

18. The plastic bag of claim 17 , wherein the plastic bag includes a first set of lines of perforation that extend 90% or more of a distance from the top of the bag to the bottom of the bag.

19. The plastic bag of claim 18 , wherein the plastic bag includes a second set of lines of perforation that are generally shorter than the first set of lines of perforation.

20. The plastic bag of claim 19 , wherein the ratio of the distance of the first set of lines of perforation to the length of the second set of lines of perforation is 2.5:1 to 1.5:1.