At one time, curbside refuse containers all looked alike. On any given weeknight, thirty gallon galvanized steel cans lined the streets of neighborhoods across the country. They were trusty, got the job done and everybody it seemed, had at least two.
But in this age of specialization, curbside containers – for either refuse or recycling – have taken on an expanded role. Today, they’re purpose-built tools of a growing trade and in more and more neighborhoods, they’re an important part of a higher-tech, coordinated system to collect household solid waste, and begin the sorting process for recycling, as quickly as possible – at the lowest necessary cost.
Plastic refuse containers have been in widespread use for more than 25 years. Since their inception, they have evolved to meet the changing demands of solid waste handling. Compared to the earlier steel cans, plastic refuse containers cost less to manufacture, last a long time and are available a wide variety of colors, shapes, sizes and design variations. Of late, containers are playing a more important role in automated refuse collection systems as well.
In most cases, the material used to manufacture refuse and recycling containers is polyethylene – either high-density polyethylene or linear low-density polyethylene - or polypropylene. True to form, the polymers often contain PCR, post consumer resins, from previously recycled plastic products. The blend of plastic, as well as the method for molding, determines the rigidity of the end product.
Whether it’s refuse containers or recycling containers, there are essentially three methods to manufacturing them – blow molding, injection molding and rotational molding.
Blow molding relies on air pressure to form a thin layer of near molten material over tooling for the product. As the resin cools, the mold is opened and finished plastic parts are trimmed or processed further, depending upon the product specifications. While there are several blow molded refuse containers on the market, blow molding is advantageous for manufacturing thinner walled products such as plastic bottles.
Another method to manufacture plastic refuse containers is by injection molding. Ella Kraft, of Schaeffer Systems International explains, “Injection molding relies on mechanical pressure to force plastic resin into the mold. It’s a highly controlled process that yields uniform wall thickness, smooth surfaces and a very stable product,” she said. In addition, “The smooth surfaces are important to homeowners because they’re so easy to clean.”
The process for rotational molding is quite different. A blend of granulated resins is placed in a mold that rotates. As heat is introduced, the resins flow into the mold and are distributed through the tooling by gravity. Rotational molding yields a “stress free” end product with uniform wall thickness and a very smooth surface.
Toter Incorporated, of Statesville, North Carolina is the third largest rotational molder in North America and the largest manufacturer of curbside containers. Larry Boppe, president of Toter Incorporated points out, “Stress is the enemy of plastic. When we engineered our latest line of EVR products, our goal was to build the toughest refuse container on the market. Today’s automated collection systems put a lot of pressure on the sidewalls of refuse containers. To build the highest performance containers, we start with a blend of linear low-density polyethylene. Then our patented, ‘advanced rotational molding’ technology produces a cart that not only conforms to ANSI standards, but meets the aesthetic requirements of more discriminating, upscale consumers,” he said. Toter recently won a large municipal contract for containers on the basis of durability, and for their unique, granite colored appearance. “Our molding process allows us to blend several different colors of ‘granite’ that we offer in addition to a wide selection of solid colors,” noted Mr. Boppe. “It’s a nice looking product. Refuse containers are no longer kept in the back of the store,” he said.
In most communities, homeowners choose and purchase their own curbside containers, but more and more units are being sold through municipalities and waste hauling contractors. Mark Ahrendt, sales representative for SCL A-1 Plastics, Ltd. of Brampton, Ontario, manufacturers of injection molded curbside recycling containers observed, “The sales process usually involves working directly with the public works administrators. We discuss needs, provide samples, review budgets and develop a firm set of product specifications. Then the business is typically put out for bid. Most customers prefer two or three finalists in the hunt before an order is awarded,” he said.
Although they appear rather simple, curbside recycling containers reflect specific design criteria as well. “They’re rectangular,” notes Mark Ahrendt. “Even when full, they don’t weigh very much, so the shape gives added stability. A rectangular container is less likely to be affected by wind,” he said. Many curbside recycling containers can also be stacked, taking up less room wherever they’re placed.
Municipal recycling programs are in place in thousands of communities throughout the United States and Canada. In addition to specialized containers, collection trailers play an important role in keeping many forms of household solid waste from entering landfills.
Gary Hansen, sales representative for Wilkens Industries, Inc., manufacturers of custom recycling trailers in Morris, Minnesota said, “We build trailers to meet the specific needs of our customers. From a standard steel frame assembly, we equip each unit with the number of bins they require, depending on the types of material they recycle. We offer both aluminum bins and an all-steel design as a lower cost option. Municipalities that provide curbside pick-up prefer our hydraulic bin dumping system. In cases where consumers bring recyclables to the trailer, our non-hydraulic bin system is very popular,” he added. Mobility is an important design consideration for recycling trailers as well. A typical trailer is no more than 24 feet long, and can be pulled by a full size pick-up truck, without the need for a commercial driver’s license in most states.
“Recycling trailers should meet the needs of all users,” said Richard Ehmke, product designer for Alley Cat Depco in Beatrice, Nebraska. “We got started building trailers in 1995 with a grant from the Nebraska Environmental Trust. Our units are made from all recycled steel and plastic, and they conform to ADA (Americans with Disabilities Act) guidelines so everyone can use them. The majority of the trailers we build are parked in a given location in town. Residents then bring their recyclables to the trailer,” he said.
As the focus on recycling at the community level grows, so too will demand for recycling trailers. Producers report sales are up, with lead times as long as 120 days.