July/August 1995
Equipment from Inter-Source Recovery Systems turns raw, dirty, chips into clean, valuable scrap with a minimum of fuss.
Jeff Borsecnik
Jeff Borsecnik is an associate editor of Scrap Processing and Recycling.
Chips and only chips—that's the scrap processing niche Inter-Source Recovery Systems Inc. (Kalamazoo, Mich.) targeted when it began building automated systems for separating machining fluids from turnings a little more than a decade ago.
And that's still the equipment maker's sole focus, making it the only manufacturer- aside perhaps from the odd one-man shop—to exclusively produce chip processing systems, according to the president and founder of Inter-Source, William D. “Bill” Nemedi.
Seeking Something 'Stouter'
Inter-Source itself began as a one-man shop—although one without a shop, so to speak.
Bill Nemedi, who had worked for a firm that manufactured chip processing systems among other equipment, set out on his own in 1984. “I was encouraged by potential customers to consider developing my own product," he recalls, citing a need at the time for "stouter, more serviceable equipment- something stronger, faster, and less expensive than what was then available in the market.”
The one-man company soon made its first sale, to a nearby screw machine shop, and, lacking a manufacturing facility and employees, enlisted the help of several contractors to produce this first system. With this experience under its belt, Inter-Source incorporated in 1985, with Bill's brother, Robert J. “Bob” Nemedi, joining as a partner and operations manager and Gary Hurd coming aboard as an engineer the following year.
Along with expanding its staff, the company also began to gradually expand its customer base, first among Michigan screw machine shops, then other manufacturers—especially first-tier automotive industry suppliers—and, eventually, the major automakers themselves.
Inter-Source reached a major milestone in 1990, when it won a patent for a wear-and-tear-saving design on its chip wringer—the centerpiece of an automatic chip processing system.
Another milestone came in 1991, when the firm opened its own manufacturing facility. Even with this facility, however, much of Inter-Source’s routine production and assembly is performed by external contractors—especially Camfab, a fabricationshop located in nearby Martin , Mich. This contractor, which now performs work almost exclusively for Inter-Source, “grew out of our company's startup,” explains Bob, “and we don’t see any need to alter the situation.”
Such contractor arrangements not only demonstrate the company’s strong loyalty to those shops that lent a hand to the fledgling company early on, but they also enable Inter-Source to focus the efforts of its staff of 12 on product development rather than the nuts and bolts of routine production.
The company does manufacture all of its more-complicated and first-time components at its own shop, though the facility doesn’t look like much of a factory. It sits in a total wooded area near the edge of Kalamazoo , its lawn dotted with bird houses put up by a neighbor. And it’s not dim, smoky, or loud, which males it ideal for its other function—a visitor demonstration center.
Cleaning Up: A System in Action
Inter-Source’s chip systems consist of several interlinked components that transform fresh “wet” chips—granular or stringy turnings coated with machining fluid—into clean scrap and reusable lubricants and coolants in a continuous automatic process.
Capacities range from a few hundred to several thousand pounds per hour, with the average user running around a ton per hour through the line. The systems can also vary depending on the type of turnings handled as well as the configuration of the customer’s operation. Nevertheless, they all work something like this:
At the front end is a receiving hopper, typically with a hydraulic cart dumper equipped to handle carts wheeled in from the machining area. Chips are fed from the hopper toward the processing equipment by an inclined screw conveyor, which meters the flow, moves the material—even troublesome balls of stringy turnings—up an incline, and helps classify chips by size: Balls of stringy tend to remain intact as they ride along the top of the rotating screw toward their destination, while smaller grainy chips slide down among the auger flighting (threads) as they move forward.
At the end of the screw conveyor balls of stringy turnings are fed into a slow-speed shear shredder, whose twin rotors are positioned one above the other and parallel to the ground. The shredder shears the chips into a reasonably homogenous stream of flowable material that optimizes the effect of the downstream chip wringer.
But very little material actually goes through the shredder, which Inter-Source promotes as an advantage of its machine because it saves wear and tear. The grainy chips as well as drill bits, machine parts, and other tiny “solids” small enough to fall within the screw conveyor helix drop beneath the face of the shredder, circumventing it—they don’t require shredding—and fall through an opening at the base of the shredder. And as the masses of stringy turnings are steadily sheared apart at the face of the shredder, most of the resultant shreds fall to the base of the shredder face rather than feeding through the machine, joining the other materials that circumvented the shredder to move downstream, along with any material that actually fed through the shredder.
“Nested Solids” such as tool parts and bar ends wrapped up in the stringy turnings are unnested by the gnawing action of the shredder. When the cutting disks encounter these solids, the shredder quickly senses they are trouble and automatically reberses to spit them out, protecting the machine.
All of the materials then drop diagonally through a “parts separator,” a pneumatic air-classifying device powered by an air current generated by the downstream chip wringer. The relatively light chips and liquids jump a gap, separating them from heavier solids, which are expelled into a bin.
Next comes the wringer. The chips and associated fluids that passed through the parts separator drop from above into a shallow spinning bowl enclosed in a large metal cabinet and fitted with several radial fins or blades. As the bowl spins, the chips migrate up its inside surface. Centrifugal force separates the flood from the chips as they spin, and these liquids pass through a heavy-duty “wedge wire” screen and drain into a holding tank.
A drag conveyor in the tank collects heavy sediments from this sludge or “swarf” and recirculates them from this sludge or wringer, which results in greater metal recovery and less waste remaining in the collected fluids. The remaining in the collected in the reservoir is automatically pumped out for additional filtering or direct reuse by the plant’s machining operation.
The chips, meanwhile, are forced out over the top edge of the bowl by the spinning blades. Air currents generated by the wringer propel them through overhead ducts as far as 100 feet—no additional compressors or blowers are needed—and into awaiting containers. The air expelled from the system is no dirtier than ambient shop air, thanks to the effectiveness of the chip wringer at removing the machining fluids, according to Bill.
Variations on the Theme: Custom-Building Components
Given the many variables at every operation that could use a chip processing system, “almost every Inter-Source system is an individual,” says Bill. “Even our standard equipment package can be assembled in any number of unique configurations tailored to specific customers' needs and limitations.”
The company promotes, for example, its willingness to build its hydraulic cart dumpers to match a customer's existing chip carts, freeing the buyer from an obligation to replace existing equipment. In fact, since the size of the collection cart essentially determines the maximum size of a bundle of chips—at least in the case of stringy turnings, Bill explains—and since the system components are designed based on the largest bundle of material to be handled, everything can be tailor-made to match the customer’s chip carts.
Custom- building also allows Inter-Source to include additional components in its systems, such as automatic or manual switches at the back end of a system that can deflect the clean scrap into backup containers as others fill, as well as sensors that detect missing or full containers and initiate a system pause or rerouting of chips.
In addition, the company may replace various standard components with custom-designed equipment that better meets unique customer needs. As an example, for some customers, particularly large, sophisticated operations, Inter-Source supplies liquid tight automatic in-floor rib conveyors to collect the turnings and machining fluids from all around the plant floor, replacing chip carts and the labor required to move them around by hand.
Many system variations are attributable to different types of turnings. Systems handling a lot of stringy chips usually use a double-screw conveyor because these chips tend to bind together into tumbleweed-like balls, which are most easily handled intact transported atop the twin screws.
Systems that handle only granular chips, meanwhile, may not need a shredder for product sizing, and in some instances a parts separator may not be required, so the line might consist simply of a hopper, chip wringer, and a conveyor. Further, in cases where a small proportion of the chips are stringy, a relatively small shredder is used, incorporated into the end of the infeed screw conveyor, while when a majority of the mix is stringy chips, a heavier, independent shredder is employed.
In other words, there are literally hundreds of different configurations possible in Inter-Source’s systems.
Emphasis on Innovations
Price tags for a complete system—like the systems themselves—vary widely, but a ballpark figure for a modestly equipped system might be about $100,000, according to Bill, who says: “We’re not interested in being the lowest bidder—though we’re rarely the highest—but we are consistently the most complete bidder, including things in our proposal others only offer as options after-the-fact.”
For example, the company offers as standard equipment programmable logic controllers on all of its equipment. This computerized circuitry “provides a level of intelligence to an otherwise unglamorous piece of equipment, enabling intelligent interaction between system components,” says Bill. Sensors in each component collect data, which are then compared, allowing the machine to automatically coordinate the operation of different machines or warn of problems if necessary. For instance, if the shredder reverses to protect itself when presented with an indigestible chunk of metal, it signals the infeed screw conveyor to pause while the problem item is removed.
Bill sees continual innovation as vital to drawing attention to the company and attracting prospective customers. The most significant Inter-Source innovation to date, in his estimation, is its cast bowl-and-blade system for its larger chip wringers, which solves a long –running wear problem in this equipment.
The position of the wringer blades determines the route of migration of the abrasive chips up the bowl, and wear tends to be concentrated right in front of the blades, causing uneven wear on the bowl and, eventually, requiring its replacement. Though some manufacturers design the bowl to allow periodic blade repositioning, this does not slow overall wear, it just spreads it out, according to Bill.
So Inter-Source came up with a design that actually eliminates wear on the bowl by allowing the blades to take on much of the abuse traditionally imposed on the bowl itself. The system employs bolt-in cast blades that are T-shaped in the cross section. The top of the "T" is the base of the blade--the "T" is turned on its head--which fits snugly into a radial recess in the cast bowl. The base of the blade then forms a continuous surface with the bowl itself, acting as the wear surface immediately in front of the upright portion of the blade. When the wear becomes excessive, the blades, rather than the whole bowl, can simply be replaced—a quicker, cheaper alternative.
Inter-Source equipment also offers other “unique attributes throughout the entire system,” Bill says. “Though their significance is not necessarily patentable, they keep us competitive in the marketplace,” he notes. “We’re always getting new concepts, a new approach, new components, and integrating them into the tried-and-true system.” And as Bob points out, even older existing systems can sometimes benefit from new improvements through retrofits.
In addition to promoting its advancing technology, Inter-Source boasts of the exacting “fit and finish” of its equipment. As Bill puts it: “Chip processing equipment has the reputation of being nasty equipment that looks dirty and ugly, so no one wants to maintain it. Our approach is to make a functional package but incorporate aesthetics." This, he says, lends the equipment the appearance of being an integral component of the manufacturing process rather than an extraneous add-on, which ensures that it is much better maintained—something more and more customers are catching on to.
Environmental Pressures Boost Automatic Chip Processing
Demand for chip processing equipment originally evolved as machine shops sought to cut the expense of lost cutting oils, which cost up to $7 a gallon and traditionally accounted for 10 to 20 percent of the weight of raw chips—potentially adding up to hefty losses.
But over the last few decades, machine shops have trended toward use of inexpensive coolants diluted in water instead of traditional cutting oils. The original idea was that these would pose less of an environmental problem than the oils and hence would not need to be wrung from the chips at all, Bill explains.
But that way of thinking has changed. The water-soluble coolants are highly visible and they are used in high volume, tending to create where they collect “a milky colored pond that lends the appearance of being very severe environmentally,” Bill notes. Fears of the appearance and costs associated with environmental contamination have thus prompted more chip generators to consider chip processing equipment making the trend toward coolant as opposed to lubricating oil a boost for the demand for chip processing systems. (Inter-Source's equipment doesn't discriminate between oils and coolants, notes Bill.)
Such environmental concerns are certainly an area where scrap generators' and scrap processors' interests coincide. And while Inter-Source does not see processors as a primary market for its equipment, the company sees them as natural allies in reaching scrap generators because the recyclers can describe to their suppliers the environmental benefits—as well as the improved scrap values and labor savings presented by automatic chip processing systems.
Equipment from Inter-Source Recovery Systems turns raw, dirty, chips into clean, valuable scrap with a minimum of fuss.