|
 JJohn W. Bartok Jr.
|
Q: What are my options for recycling used greenhouse film?
The greenhouse and nursery industry uses an estimated 35 million pounds of plastic film that must be disposed of each year. As the cost of oil increases, the price that recyclers are willing to pay for this discarded plastic has been increasing. A check of the internet shows recyclers are paying from $0.06 to $0.12 per pound depending on the cleanliness of the plastic.
It is estimated that hand removal of plastic costs growers 20 to 60 cents per pound and as much as 50 cents per pound for trucking and tipping fees to dispose of it. Keeping it clean, sorting and baling it has allowed some growers to break even or realize a small profit since some recyclers are willing to pay for large quantities of recycled film.
Film handling
To be of value to a recycler, the plastic should be sorted by type, be clean and be baled for easy handling. Before the plastic can be converted into pellets for recycled products, it goes through several processes. It is first inspected for contamination from soil, pesticides, organic matter and ultraviolet light degradation. Since much of the greenhouse plastic that is used today is coextruded with additives, such as ultraviolet light stabilizers, anti-condensate control, infrared inhibitors and shading compounds, sorting by type is important.
If acceptable, the film is chopped in a grinder, washed to remove contaminates and fed into an extruder where heat and pressure melt the plastic. The molten plastic is then extruded into fine strands, cooled and chopped into pellets. Recycled plastic pellets are one of the components in plant containers, lumber and other consumer products.
Small budget solution
For small operations, the removal and disposal of the plastic film does not present much of a problem. Some growers roll or fold the sheets and use them as covers for temporary storage of materials or for weed control under containers. Others cut the large sheets into manageable sized pieces and give them away to customers or neighbors. They make good covers for wood piles and lawn equipment.
Very few landfills take film plastic, as it is bulky and has a long life before it breaks down (about 400 years). Some states such as New Jersey, Michigan and New York have successful recycling programs with collection centers where growers can bring the plastic. Some growers dispose of the plastic through a local recycler that compresses it into 500-pound bales and sells it to a broker. Much of the material is shipped to Asia where it is used in export products.
Hand reels are convenient for densifying small quantities. These homemade devices, which handle a 40- x 100-foot sheet, can be attached to a truck or wagon bed for portability. A tapered core helps remove the plastic.
The volume of plastic should be limited to rolls of less than 100 pounds for easy handling. Plastic hay bale twine can be used to keep the roll of film from unwinding.
Powered rollers are available from several companies. The tractor power-take off or hydraulic motors are usually the power source. Roll width and diameter vary by design. During operation one end of the plastic sheet is attached to the roll. Several people may be needed to guide the material as it is being rolled.
|
