HOW TO HANDLE MACHINE TOOL PROCESSING SCRAP SAFELY

A review of the latest advancements in scrap conveyor technology for the economic removal of coil scrap, machine tool chips and magnetic separation of contaminates.

APPLICATIONS FOR STAMPING
Stamping Scrap Conveyor Redesigned for In-Floor Retrofit Applications
PRAB (Kalamazoo, MI) uses an innovative off-set trough design for its ScrapVeyor™ stamping scrap conveyor to meet the unique space requirements for retrofit in-floor applications. Traditional in-floor designs of the ScrapVeyor have utilized a flat or symmetrical V-style trough design. The off-set design allows the conveyor to fit within tighter spaces.

“We meet the customer’s challenge by engineering this twist on a design with decades of proven reliability and efficiency,” noted Gordon Brodhagen, PRAB conveyor project manager. “The off-set trough design allows the conveyor to fit within an existing in-floor pit to achieve significant installation savings for the customer.”

The ScrapVeyor is a fully automated conveyor that uses positive discharge to ensure zero carryover. Its leak-proof construction retains 100 percent of cutting fluids as it transfers scrap up to 300 ft (90 m) in both above-floor or in-floor applications. Larger rollers keep the flighted chain on track, while rotating flight cams provide less friction for cooler, longer operation. Discharge options include standard chute, automatic or manual pivoting swivel chutes, as well as an automatic or manual tipping chute for use with single, dual or full-size trailers or railcars. www.prab.com

APPLICATIONS FOR MACHINING
Eliminate Chip Carryback
The ChipBlocker®  from Jorgensen Conveyors, Inc. (Mequon, WI) is a retrofitable accessory unit that attaches to most makes and models of chip conveyors that provide chip scrap removal on CNC metal cutting machine tools. It is a compact unit that mounts to the discharge end of a hinged steel belt chip conveyor. It uses coolant to flush the underside of an operating conveyor belt to knock off any metal chips which are sticking to the belt so that they don’t get carried back into the conveyor housing. It virtually eliminates chip carryback!

“Chip carryback on the surface of the conveyor belt is a common problem in CNC metal cutting machine tool chip conveyor’s operation,” explains John D’Amico, co-principal and director of sales for Jorgensen. “The ChipBlocker® uses clean coolant from the machine tool coolant supply tank to gently wash the chips off the belt after the discharge point but before the belt returns to the conveyor housing.”

Chip migration from the conveyor into the machine’s clean coolant tank is a common and pervasive problem that leads to machine downtime for tank maintenance, clogged coolant supply lines, damaged tooling and poor part finish quality.  “For a very small investment, the ChipBlocker®” provides fantastic payback in machine uptime gains, less maintenance and improved quality of the parts being machined,” notes D’Amico. He also adds that this unit can help reduce coolant carryout from the conveyor and provide longer coolant life. “This product definitely supports the growing trend for green manufacturing and better use of consumable products in the manufacturing process,” smiles D’Amico.

Auger Conveyor
Jorgensen also builds a centerless auger conveyor that uses a centerless screw design for removal of small chips from machining operations when space requirements restrict the use of other types of conveyors for chip removal. “These conveyors can be built in a very low profile to fit into tight areas where the envelope is restricted,” says D’Amico. “Many of today’s metal cutting machining centers are equipped with auger conveyors inside the machine to transport the chips and coolant to an external conveyor.” Jorgensen can design and build replacement augers for these internal conveyors, or complete replacement auger conveyors.

Jorgensen will design and build the auger conveyors to the particular size requirements of the application. According to D’Amico, no other supplier of chip conveyors and coolant filtration systems offers a broader range of engineered product solutions for the wide variety of CNC metal cutting machine tool applications seen in today’s marketplace.

Vacuum Drum Filtration
Jorgensen also provides its patented Convey-R-Vac® vacuum drum filtration system, a unique permanent media filtering solution for metal cutting machine tools. “It performs to greater filtration efficiencies at lower micron particulate levels than any of the competition’s gravity flow permanent media filter offerings,” says D’Amico. “The filter drum remains stationary and a pump is used to pull the dirty coolant through the media. We allow a cake of swarf to build on the filter media to aid in finer filtration.”

According to D’Amico, other conventional gravity flow drum filtering systems rotate the drum continually and back flush it because they have to rely on gravity to flow the coolant through the filter media on the drum.   Because of this, the media must be continually cleaned. This results in more migration of finer chips through the media on these systems. But on the Convey-R-Vac, a cake builds on the media and as it continues to build up, the vacuum increases to a controlled set point.  When it reaches that point the drum will index 120 deg and go through a back flushing process to clean the filter media so that the machine tool coolant flow rate can be maintained.

The Convey-R-Vac system is particularly effective in cast iron machining applications where the conventional gravity flow drum systems do not perform well due to the high percentage of very fine particulate found in cast iron swarf.  It also works very well in all other typical machining applications involving steel, aluminum, brass, etc. Jorgensen can integrate primary chip removal conveyors, secondary filtration, high pressure coolant pumps, coolant chillers and complete controls with the Convey-R-Vac for a turnkey system.

Gravity Roll Media Filters
Jorgensen also supplies a line of standard Gravity Roll Media filters, including its 30 gpm unit with a clean coolant tank and coolant supply pump. “We offer the gravity roll media filter line with standard filter sizes of 30 gpm, 60 gpm, and 90 gpm flow rate capacity, along with standard tanks in four different sizes,” says D’Amico. The 60 gpm and 90 gpm filters can be mounted interchangeably on any of three tank sizes for different coolant volume capacity requirements. These filters use deep filter cakes for efficient filtration performance in grinding and metal cutting machining operations where there is a high percentage of very fine chips generated in the process.

This line of gravity roll media filters incorporates a “seal wheel” to provide a positive seal of the filter media to assure no fine particulate can migrate around the paper into the clean tank. These filters can be used for primary or secondary filtration and can be integrated with other conveyors in systems. A standard control package is optional. According to D’Amico, no other supplier of chip conveyors and coolant filtration systems offers a broader range of engineered product solutions for the wide variety of CNC metal cutting machine tool applications seen in today’s market place. www.jorgensenconveyors.com

APPLICATIONS FOR GRINDING, METAL CUTTING
Magnetic separators remove ferrous & nonferrous contaminants from coolants and oils.
Polytech Filtration Systems, Inc. (Hudson, MA), a leading innovator in machine tool coolant filtration, updated its line of magnetic separators for grinding and metal-cutting operations. Polytech magnetic separators for coolant cleaning improve tool life while reducing operating expenses and the environmental impact of machining.

Polytech’s advanced magnetic separators reduce filter cartridge consumption and element changes when used with surface grinders, gear grinders, honing and lapping machines, broaches, milling and drilling machines, face grinders or oil reclaiming machines. They extend the effective life of coolant, cutting tools, grinding wheels, pumps and other filtering devices by reducing the concentration of small fines left in machine coolant by chip conveyors in broaching, milling and drilling operations.

Polytech engineering manager Chris Ashley explains, “Magnetic separators significantly reduce the concentration of metal chips and fine particles in coolant and cut costs through improved abrasive and cutting tool life, as well as extended coolant change intervals. Magnetic separators can be applied to existing tanks as full-flow or side-loop separators to leverage existing equipment investments. As a first stage, magnetic separators can be very effective in reducing the cost and environmental impacts of downstream disposable filters.”

Polytech magnetic separators for coolant cleaning are reliable, rugged and are available in a range of standard sizes and can handle up to 185 gpm of water-based coolant and up to 93 gpm of oil-based coolant. All Polytech magnetic separators easily install on new or existing machines to provide years of maintenance free operation. Their easy-to-maintain design consists of a magnetic drum made up of alternating permanent magnets and steel discs. The magnetic field is extended by the magnetized steel discs to maximize effectiveness without resorting to more costly high strength or rare earth magnets and a comb type scraper and adjustable discharge chute optimizes sludge removal.

Configurable with a wide array of options, Polytech engineers can easily find the right magnetic separator to fit a customer’s specific coolant cleaning needs. Specific system pricing is determined by factors including application and facility requirements of the customer and the number of systems ordered. www.polytech-filtration.com