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Injection Molding

Simple Design, Proven Performance

Miniature Plastic Molding (MPM) is a top injection molding machine manufacturer known for its affordability and efficiency.

MPM’s Mini-Jector Machines are available in pneumatic, hydraulic or electric models, with either plunger or reciprocating screw type plasticizing systems.  All Mini-Jectors may be used with a wide range of thermoplastics, ceramics and various investment waxes.

The low price of the Mini-Jector, combined with its low tooling costs, makes small production runs of 100 pieces as economically efficient and practical as runs of much larger quantities.

What Can Injection Molding Do?


  • SEISMIC CABLE OVERMOLDING

  • COLOR MIX TESTING

  • TRADITIONAL ASTM TENSILE SPECIMENS

  • PROTOTYPES OF NEW OR TRIAL PARTS

  • INSERT MOLDING OR OVERMOLDING

  • EDUCATIONAL PROGRAMS

Mini-Jector Model #45

    • Requires only 115 or 220 VAC 1 Phase supply
    • One (1) high capacity heating cylinder
    • Plunger assembly choice of  bore sizes
    • 0.33 ounce to 3.0 ounce “shot” size
    • Non-drool nozzle
    • Straight orifice nozzle (0.125” diameter) also available
    Pneumatic System
    • One (1) 8”x6” air cylinder or optional multi-stage cylinder for higher injection pressure
    • Air filter regulator unit to be used with customer’s air supply
    • 125 PSI maximum operating pressure
    • One (1) solenoid operated directional valve
    • Valve is pre-lubricated and does not require air supply lubrication
  • Heating System
    • One (1) 1050 watt cylinder heater
    • One (1) 150 watt nozzle heater
    • Two (2) 1/16 DIN  pyrometers with auto-tune feature to control cylinder and nozzle heaters
    Additional Features
    • Aluminum material hopper with dump tube and shut-off
    • Self compensating automatic material feed system
    • NEMA 12 electrical enclosure with external pushbuttons
    • Controls for manual or semi-automatic operation
    • Digital injection timer
    • Safety shroud covering all moving parts
    • Optional C-Frame version available
  • mini-jector-45

Mini-Jector Model #50 

    • One (1) high capacity heating cylinder
    • Plunger assembly choice of bore sizes:
    • 0.33 ounce to 3.0 ounce “shot” size
    • 230 VAC single or three phase power supply options
    • Sliding ring shut off tip with “non-drool” shut-off nozzle
    • Straight orifice nozzle (0.125” diameter) also available
    Hydraulic System 
    • Self contained hydraulic power unit
    • 5.4 gallon reservoir
    • 2 HP pump motor
    • 2.0 GPM pump 
    • One (1) 2” x 6” hydraulic cylinder
    • Remote relief valve to control injection pressure
    • Solenoid operated directional valve for ram (plunger) movement
  • Heating System
    • One (1) 1050 watt cylinder heater
    • One (1) 150 watt nozzle heater
    • Two (2) 1/16 DIN auto tune pyrometers that control cylinder and nozzle heaters
    Additional Features
    • Aluminum material hopper with dump tube and shut off
    • Automatic self compensating feed system
    • Thermal overload breaker for heater 
    • Control system with circuitry for manual or semi-automatic operation
    • Includes digital injection timer
    • All moving parts covered by safety shroud
  • mini-jector-50

Mini-Jector Model #55

    • Accommodates mold to 5.5″H X 8.5″L X 6.0″W
    • 230V single phase & 230 / 460 V three phase power
    • Reciprocating screw with 2.5:1 ratio and flame hardened flights
    • Screw assembly choice of bore sizes:
    • 7/8” – max shot size: 1.00 ounce
    • 1 1/16” – max shot size: 2.00 ounces
    • 1 3/8″ – max shot size 4.00 ounces
    • Nitralloy screw barrel
    • Sliding ring shut off tip with “non-drool” shut-off nozzle
    • Direct hydraulic drive screw
  • Control System
    • Directional valves with plug-in connectors that control:
    • Screw speed
    • Injection pressure
    • Injection speed
    • Screw back pressure read on oil filled gauge
    • Timers for overall cycle and injection forward time
    • Full manual controls
    • Motor starter with thermal overloads and emergency stop button
    • Vernier adjustment for shot size
    • Selectable 1/4” de-compression feature
  • mini-jector-55

  • Hydraulic System 
    • Two injection cylinders 
    • One carriage cylinder
    • Self contained hydraulic power unit features:
    • 5.4 gallon reservoir
    • 1725 RPM motor with 2 HP
    • 2.0 GPM gear pump immersed in the reservoir
  • Heating System
    • One nozzle heater
    • Two barrel heaters 
    • Three 1/16 DIN auto tune pyrometers that control front, rear, and nozzle heat zones
  • Additional Features
    • Aluminum material hopper with shut off and dump tube
    • Moving parts covered by safety shroud
    • Heat shield on barrel
    • Greaseless bushings used in screw unit mechanism
    • Provision for cooling feed throat

Mini-Jector Model #55-1E

    • 230V single and three phase  phase power options
    • 7/8” diameter reciprocating screw with 2.5:1 ratio and flame hardened flights
    • Nitralloy screw barrel
    • Sliding ring shut off tip with “non-drool” shut-off nozzle
    • Drive screw powered by Mitsubishi Servo with 25:1 Shimpo Gearbox
    • Twin injection screws powered by Mitsubishi Servo with 15:1 Gearbox
    • Carriage screw powered by Mitsubishi Servo with 81:1 Gearbox
    • Mitsubishi MR-J3 B series servo amplifiers
    Heating System
    • One nozzle heater
    • Two barrel heaters
    • Four channel analog temperature control with solid state relay output
  • Control System
    • Mitsubishi  Series PLC control
    • Mitsubishi Color Touch Screen
    • 5 step programmable injection profile
    • On-screen position & velocity trending of injection
    • Force and Temperature monitoring
    • Data selectable English or Metric units
    • Velocity is held within 0.02% 
    • Position is held within 0.001”
    Additional Features
    • Aluminum material hopper with shut off and dump tube
    • Moving parts shielded by Lexan guarding
    • Heat shield on barrel
    • Integral hopper tube and bearing chiller system
  • mini-jector-55E

Mini-Jector Model #75

  • Horizontal Injection, Vertical Clamp
    • 12.5 ton hydraulic vertical clamp with 5.00” stroke
    • Maximum daylight opening of 10.75” (without shuttle) and 10.00” with shuttle option
    • 230V single phase and 230 / 460V 3-phase power options
    • Parting line injection
    • Reciprocating screw with 2.5:1 ratio and flame hardened flights
    • Screw assembly choice of bore sizes:
    • 7/8” – max shot size: 1.00 ounce
    • 1 1/16” – max shot size: 2.00 ounces
  • Hydraulic System
    • Self contained hydraulic power unit features:
    • 12.5 gallon reservoir
    • 1725 RPM pump motor
    • 6.0 GPM pump
    • Hydraulic motor
    • Hydraulic manifold features:
    • Proportional relief valve and directional valves
    • Mounted at rear of machine for easy maintenance
    • Two (2) Sheffer injection cylinders
    • One (1) Sheffer carriage cylinder
    • Mold ejector cylinder with 2” stroke
  • mini-jector-75

  • Machine Controls
    • Mitsubishi PLC 
    • Touch screen operator interface
    • Storage in control memory for 36 recipes and setups
  • Safety Features
    • Pneumatic safety gate
    • Cycle started with two-hand anti tie-down buttons
    • E-stop circuit is electrically, hydraulically, and mechanically interlocked
  • Additional Features
    • Aluminum hopper 13 lb. capacity with dump tube
    • Mounting is provided for 5” x 8”, 6” x 8” shuttle bases plus MUD frames