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M.R. Mold Molding Accessories

Pneumatic "Stuffer Box"

stuffer boxStuffer boxTired of cleaning pumping units after constant material changes? Don't want the hassle of setting up or breaking down a pumping unit after short-run, prototype or micro-mold production? M.R. Mold & Engineering's stuffer box is your answer. With our stuffer box, the material is fed directly into the machine barrel, eliminating the need for cleaning the pump or material feed mechanism.

Capabilities of Both Units

  • Chamber is 420 hardened stainless steel
  • 3/4-14 NPT female thread to connect the stuffer box to your molding machine
  • Material is fed directly into the machine barrel.

Low-Volume, High-Pressure Stuffer Box – LVHP27      

  • Volume: 27 cubic inches or 1.1 pounds of pre-mixed material
  • Capable of feeding LSR, gum stock silicone and some organic rubbers
  • With a 10:1 intensification ratio, 120 psi air pressure generates 1200 psi on the material.

 Stuffer BoxStuffer BoxHigh-Volume, Low-Pressure Stuffer Box – HVLP78       

  • Volume: 78 cubic inches or 3.1 pounds of pre-mixed material
  • Capable of feeding LSR and some gum stock silicones
  • With a 3:1 intensification ratio, 120 psi air pressure generates 360 psi on the material.

Our stuffer box comes with a controller which can be used to regulate air pressure to the unit.

The stuffer box is equipped with a 3/4-14 NPT female thread as an adapter to attach to the barrel of the molding machine. (An adapter plate may be needed if your barrel does not have this thread.) Unlike a conventional pumping unit, the "A" and "B" parts of liquid silicone rubber must be manually pre-mixed before feeding into the stuffer box. At the end of the run, the stuffer box can be unscrewed and stored in a refrigerator or freezer to preserve the material inside.

Upon request, M.R. Mold & Engineering will test feed your material into our stuffer box prior to purchase to ensure functionality.