Multi-Tasking (Baler Supplement)

Recycling companies are no strangers to multi-tasking: they scramble to bring material in, to process it efficiently, and then to find a buyer for the material, often with the same person involved in all of these tasks on the same day.

Similarly, a baler at a material recovery facility (MRF) or other multiple-material processing plant might also end up being a multi-tasking specialist. Plant operators who need a baler to compress a variety of materials probably need to consider that aspect of their operations when looking for the right baler.

THE MRF DILEMMA

Balers can be found in any number of recycling operations, from the highest-volume scrap yards to the back rooms of discount stores. In some cases, balers can be purchased with the outlook that they will be handling primarily (or even exclusively) one material.

Shopping for a baler that is going to be used solely for cardboard or aluminum cans may not be downright simple, but it does eliminate some of the considerations that would otherwise be present.

While many recyclers will be using balers for multiple materials, operators of MRFs stand out as the people most frequently needing a baler that can switch from one material to another in the course of a work day.

“I think the MRF is most likely to pursue the ability to bale a wide range of materials,” says Jeffrey Van Galder, national sales manager with Excel Manufacturing, St. Charles, Minn.

Although MRFs have always handled several different recyclables, Van Galder notes that evolving collection and processing methods are making MRFs need to be even more versatile. “With the prominence of single-stream emerging, this ability to process a wide range of materials becomes even more important,” he says.

In single-stream operations, the sorting, separation and conveying of materials becomes part of an overall system in which baling is just one part of the equation. As described by Erik H. Eenkema van Dijk of Van Dyk Baler Corp., Stamford, Conn., in a feature story in the January 2000 issue of Recycling Today, a single-stream MRF may consist of a large number of conveyors that prepares, sorts and separates materials using speed controls, electronic eyes, load levelers, manual sorters, disc or star screens, air pressure and any number of other devices and techniques.

Ultimately, the operator ends up with several different grades of paper and types of containers that will need to be baled-and even the highest volume MRF will probably not be able to have a separate baler for each material.

A THINKING BALER

Several types of balers can handle multiple recyclables adequately. But for maximum productivity and minimal problems, Van Galder suggests that a MRF operator will need to have a baler that is programmed with a certain amount of intelligence.

“This intelligence must be apparent in all aspects of the machine: design, manufacture, programming and operation,” says Van Galder. “The baler has to be able to adapt to a wider variety of materials without the need for intensive manual labor involvement, and adapt to the different types of material being delivered to it automatically without the need for any more adjustment than changing the number of ties per bale and determining which photo eyes are being used to control the infeed flow.”

Sensors and other automatic devices can be included to detect what type of material is entering the baler and then responding appropriately by adjusting different settings. “If the baler can calculate the density of the material as it is baled, then compute how much material is needed to make the perfect bale, and then control the flow and feed rate of that material, that means effective, efficient consistent and automatic baling of a wide range of materials is possible,” says Van Galder.

At Maine Plastics Inc., Chicago, a wide variety of plastic components and containers of vastly different degrees of hardness, flexibility and shape are baled, as is the occasional load of cardboard. According to Robert A. Render, president of the company, the inherent “memory” of plastic (its desire to pop back into its former shape after its been squeezed by a baler) means Maine Plastics needs a strong baler that is also versatile.

“We bale materials with very strong memory. The memory of plastic is like no other commodity,” says Render. “It puts additional pressure on the machine, so we need as heavy duty of a machine as possible; one that is designed to direct the energy and channel it without damaging the machine or causing bowing.”

To an outside observer, seemingly soft materials such as plastic film, water bottles or tarps may not seem as “tough” as metal, with its ability to puncture and gash human skin. But to a baler, these “soft” plastics fight back a lot harder than metal. “Film has content impact modifiers, putting in even more memory,” notes Render. “If you’re baling bottles, half of your effort is getting the air out, so it’s a slower production run,” he adds.

The MRF that is handling plastic bottles faces the same challenge as Render, in addition to requiring a machine that can process paper grades as efficiently as possible to handle the larger stream of old newspapers that typically arrives at a MRF.

Van Galder suggests that there are options available with some two-ram balers that can make can make the changeover from one material to another easier for an operator. “The material feeding can be gauged to complete the bale in process and then, after this complete bale is pushed into the eject chamber, the next bale can be started with the commodity of the operator’s choice. This procedure takes some practice and planning, but it can be done very effectively,” he says.

A material separation door can also be employed. “This allows an operator to close the door behind the completed bale before starting the baling process on the next commodity,” says Van Galder. “On a single-ram baler, when materials are about to be switched, the operator can tie the first material off and then begin the next. A closed-end manual-tie baler allows the system to flow from one material to the next with minimal effort to change over.”

Thought should also be given to the wire-tying system by recyclers who are likely to bale different materials in the course of a day. “There are limitations to tying systems that have a fixed number of wires, such as when baling materials with greater memory or materials that simply need more ties to hold the bale effectively together” says Van Galder. “A two-ram baler will possess a wire tier that will allow the most flexibility in adapting the number of wires to the requirements of the material being baled, such as plastics, solid waste, or other materials.”

Although their roles and systems set-ups continue to go through changes, MRFs have been up and running for several decades now. The track records, trials and errors of MRF operators are helping baler manufacturers to pay more attention to the needs of multiple-material recyclers, resulting in equipment designed to do the job efficiently. RT