Profiles in Garbage: Plastic Film

Plastic film, which provides 39 percent of all plastic packaging, is a thin-gauge packaging used as a bag or wrap. Examples include plastic grocery sacks, trash bags, dry cleaning garment bags and plastic or stretch wrap. Plastic film is less than 10 mils thick, averaging 0.7 mils to 1.5 mils. A mil is 0.00l inch.

Most plastic trash bags are less than one mil thick.

Plastic film is a subset of a larger packaging group called flexible packaging. This larger category includes paper, plastic film, aluminum foil and cellophane that is coated, printed, laminated, co-extruded and combined, or used as a single packaging material. Paper sacks and bags, microwaveable food packaging and foil-laminated plastic pouches are examples of flexible packaging. Slightly more than half of all flexible packaging is plastic, a small amount is aluminum and the rest is mostly paper.

Recycling plastic film is difficult because the manufacturing process uses diverse resins and colors. Most bags, sacks and shrink wrap are made from low-density polyethylene (LDPE), linear LDPE or high-density polyethylene (HDPE). Polypropylene and polyvinyl chloride (PVC) also are used.

Additionally, many films blend or co-extrude two or more resins. Individual product characteristics may create remanufacturing problems. For instance, stretch wrap requires a "tackifier" so that it can cling, yet this quality is not desired in a bag.

Plastic Film Municipal Solid Waste (MSW) Facts: Generated: - 4.3 million tons of plastic film, 1.95% of MSW by weight. superscript *

- 0.84 million tons of trash bags, 0.4% of MSW by weight. superscript *

- 1.48 million tons of bags and sacks, 0.7% of MSW by weight. superscript *

- 1.98 million tons of wrap, 0.9% of MSW by weight. superscript *

- 31.85 pounds of plastic film per person per year. superscript *

Recycled: - 130,000 tons for a 3% plastic film recycling rate. superscript *

- Trash bags have a "negligible" recycling rate. superscript *

- 10,000 tons or 0.7% of bags and sacks were recycled. superscript *

- 120,000 tons or 6.1% of plastic wrap were recycled. superscript *

- Plastic film is difficult to recycle because it is thin and can be made from many different resins and colors.

- Supermarkets in many cities have recycling bins for plastic grocery bags.

Recycled Content: - Most plastic film has no post-consumer recycled content. However, pre-consumer recycled content is not usual.

- Recycled content can increase a bag's thickness by 50%.

Composted: - Plastic film does not compost unless the bags are made from degradable plastics.

- Evidence is mixed about the viability of degradable plastics in this context.

Incinerated or Landfilled: - 4.2 million tons or 2.65% of discarded MSW by weight. superscript *

- Plastic film is highly combustible with a per pound Btu value of 18,700 Btus for polyethylene, the most common film resin, compared with 4,500 Btus for a pound of MSW.

- Because plastic film does not degrade, degradable plastics are a proposed substitute. However, "degradable" bags will degrade slowly, if at all, in a modern landfill. As a result, a Florida requirement that plastic bags be degradable was repealed.

Landfill Volume: - 13.045 million cubic yards of plastic film or 3.1% of landfilled MSW in 1997.

- 2.418 million cubic yards of trash bags or 0.6% of landfilled MSW in 1997.

- 4.418 million cubic yards of bags and sacks or 1% of landfilled MSW in 1997.

- 6.209 million cubic yards or 1.5% of landfilled MSW in 1997.

Density: - A 30 inch by 42 inch by 48 inch plastic film bale, baled on a horizontal baler, weighs approximately 1,100 pounds.

- Landfilled plastic film has a density of 670 pounds per cubic yard.

Source Reduction: - Lighter in weight and less expensive than its competitors, plastic film is a prime example of successful source reduction.

Recycling Past and Present: Clean, scrap plastic film generated by manufacturing and converting operations has a long recycling history. These sources can supply sufficient amounts of clean, raw material of a known resin type. Film is palletized following a granulation or densifying process.

Post-consumer collection programs are a more recent development, which focus on establishments that are large plastic bag "generators," such as grocery stores. In this case, the recycling process is more complex, requiring sorting, washing and removal of contaminants as a first step. Plastic bag curbside collection is rare.

Recycling Markets: Plastic lumber is the primary market for recycled plastic film.

Raw Material Specifications: Plastic film should be sorted by resin, color and printed versus non-printed bags. Probably half of plastic film is pigmented, while the other half is clear, and sold to the highest value-end market.

Labels, dirt and food are the main contaminants in plastic film recycling. Other contaminants include paper receipts, staples and other nonplastics.

Sources: American Plastics Council, Arlington, Va. Website: www.plasticsresources. com

Flexible Packaging Association, Washington, D.C. Website: www.flex

"Measurement Standards and Reporting Guidelines," National Recycling Coalition, Alexandria, Va. Website:

Municipal Solid Waste Generation, "Recycling and Disposal in the United States: Facts and Figures for 1998."


superscript *1998 U.S. EPA estimates.