Hi-Tech Melt Pumps for Extrusion

WARNING: Salesmen for one extruder manufacturer are solemnly stating to customers that melt pumps cannot be used with PVC. THIS IS TOTALLY FALSE!!

The fact is that Harrel developed a melt pump for PVC over 10 years ago, and probably more PVC is used in Harrel melt pumps than any other polymer. Note also that Harrel now has a melt pump designed particularly for fluoropolymers!!

ADVANTAGES OF MELT PUMPS

• CONSTANT THROUGHPUT. Typically 0.1% stability when used with exclusive Harrel differential pressure controller.
• CONSTANT EXTRUDATE DIMENSIONS. When combined with DIGISYNCH synchronization of haul-off speed, holds dimensions to very close tolerances.
• LOWER MELT TEMPERATURE than with extruder used alone.
• GREATER ENERGY EFFICIENCY. Total energy used by extruder + melt pump less than extruder used alone.
• FREEDOM FROM PRESSURE CONSTRAINTS. Extruder screw can operate at pressure optimum for good mixing. Melt pump acts as pressure transformer to raise or lower back pressure on screw.
• BACKED BY HARREL'S 20 YEARS OF EXPERIENCE making precision melt pumps specifically designed for plastic extrusion.

STANDARD EXTRUSION PUMP

• Pressure to 10,000 PSI.
• Extremely rugged
• 12 SIZES from 0.14 cc/rev through 750 cc/rev.

PVC MELT PUMP

• MELT PUMPS DESIGNED particularly for use
  with PVC.
• NO DEGRADATION OF POLYMER in melt pump
  when used properly.

GF SERIES FLUOROPOLYMER PUMPS

• PIONEERING DEVELOPMENT BY HARREL for FEP, PFA, and other melt processable fluoropolymers.
• CORROSION RESISTANT METALS permit operation just like ordinary polymers
• ALLOWS USE OF AUTOMATED SYSTEMS like TUBETROL, SHEETROL, PROFILETROL, with fluoropolymers.

DUOSTREAM MELT PUMP

• TWO SEPARATE METERING CHAMBERS and two sets of gears on single shaft.
• GIVES TWO IDENTICAL STREAMS of plastic.
• EFFECTIVELY DOUBLES output of line, where downstream equipment is limiting factor.
• ALSO IDEAL FOR COEXTRUSION applications, where two layers need to be the same.

MELT PUMP UPGRADE SYSTEMS

• COMPLETE SYSTEM FOR ADDING melt pump precision to existing lines. Includes:
  • PRECISION HARREL MELT PUMP with pedestal support, if extruder cannot support weight.
  • PRECISION GEAR REDUCER and drive motor, mounted on support stand. Double knuckle coupling accommodates shaft misalignment.
  • DIFFERENTIAL PRESSURE CONTROLLER -- controls extruder speed to keep pressure across pump constant.
  • DIGITAL SYNCHRONIZATION with puller speed optional -- gives one-button control.
  • TEMPERATURE CONTROLLERS and power modules for control of temperature of melt pump and adapters

THE HARREL GEARTRUDER

• PRECISION HARREL MELT PUMP mounted directly on rugged Harrel Extruder, to form an integrated system.
• HARREL DIGIPANEL CONTROLLER coordinates entire system.
• MUCH EASIER TO REALIGN AFTER SCREW IS PULLED.
• EXCLUSIVE HARREL DIFFERENTIAL PRESSURE CONTROL greatly increases throughput stability -- typically 0.1%.