Maximum Output (Baler Supplement)

Without question, for bulk commodities that are traded by the ton, one of those key factors is the ability to process and ship as much material as possible in a month.

For recyclers using one or more balers as their processing machinery, that means when they shop for a baler, its ability to maximize output will be the first consideration.

A MACHINE BUILT FOR SPEED

Several design factors can combine to make a baler a high output machine.

The action of the cylinder or cylinders that compress the material inside the baler is one key factor. How much force the cylinder exerts is crucial to the density and weight of a bale, while the speed at which the cylinder can push is critical in determining the cycle time.

“The size of the cylinder will speed or slow the cycle time,” notes Richard Harris, director of sales with Sierra International, Bakersfield, Calif. Sierra distributes the MacPresse line of single-ram balers in the U.S. Harris notes that MacPresse balers, used primarily by large-volume paper recyclers, use high pressure hydraulic circuits with 4,500 pounds per square inch of pressure, which allows smaller diameter cylinders to perform heavy work.

“A smaller cylinder requires less hydraulic fluid to move the cylinder rod and increases cycle speed tremendously,” he comments. “Higher hydraulic pressure also provides a higher ram pressure, which makes for denser bales.”

Regarding configuration, Harris states that single-ram balers are faster than two-ram balers in terms of pure output for several reasons. “The horizontal or single-ram design allows the baler to operate continuously without stopping for bale separation doors, or for an operator to bind one wire at a time, or due to other errors in operator judgment.”

Advances in single-ram extrusion balers are cited as an important reason why baling output times have increased in the past decade. “Just a few years ago, the average speed of a baler was approximately 30 seconds,” says E.M. “Rheis” Asbury of Kine Corp., Plymouth, Minn. Kine Corp. is a U.S. distributor of balers made by Maren Engineering Corp. “Today, we offer balers that have seven-second ram cycles.”

Harris agrees that “vast improvements” in baler output have been achieved in recent years. “Twenty years ago a typical old corrugated containers (OCC) production rate for a large plant was six to seven tons per hour. Today, OCC can be baled at 30+ tons per hour with heavier bales,” he remarks.

The 1990s innovation of the hinged sidewall design from IPS Balers Inc., Baxley, Ga., works to increase bale density and throughput, according to IPS president Sidney Wildes.

In addition to balers with faster cycles, larger baling chambers have been created, and higher-capacity conveying systems have also been designed and built.

In a single-ram extrusion machine, “material is continuously entered into the baling chamber, and when the chamber is full, infrared sensors activate the ram,” explains Harris. “Material continues to accumulate on top of the moving ram, and when the ram retracts, the material falls into the chamber, ready for another cycle. The continuous action displaces more material per hour than other traditional designs, such as two-ram units.”

The single-ram extrusion balers, most often used for the highest-volume grades of paper but suitable for many materials, offer an additional cost per ton advantage.

The continuous-action nature of the machines means they can be set up to run without a full-time operator present. “Automation is a very important consideration in a baling operation,” says Asbury.

Asbury points to the advantages of the open-end horizontal balers offered by Maren and other manufacturers. “A closed-end horizontal, though it cycles automatically, can be labor intensive, because the completed bale must be tied manually,” he says. “By comparison, open-end balers can be equipped with an automatic bale tier, which cannot be installed on the closed-end machines.”

From a profit and loss standpoint, buying a labor-saving machine-even if it has a larger upfront cost-should quickly pay for itself in terms of wages saved.

It would most likely be premature to suggest that balers have reached a stage where they cannot be built to further increase their hourly output. “Currently the biggest obstacle in preventing balers from moving even more rapidly is the conveyor systems,” suggests Harris. “The limitation involves feeding the material to the baler fast enough.”

BALING FOR THE LONG TERM SOLUTION

When factoring in long-term production averages, avoiding downtime works its way into the equation. A high-output baler that frequently needs repairs may ultimately prove to be a disappointment.

“A good baler should perform reliably 24 hours per day, seven days per week,” says Asbury. “If the baler goes down, production is affected. A few thousand dollars saved in the purchase of a poorly designed and manufactured baler is quickly lost with unexpected downtime.”

Comparing the track records of different baler models can be difficult. Although it is an unscientific method, obtaining the opinions and learning from the experiences from as many recyclers as possible can be one way to gather knowledge about which models stand the best chance of passing the reliability test. RT

The author is the Editor of Recycling Today magazine.