Hot Runner Valve Gate Stack System

If your application requires a Hot Runner Valve Gate System, MDi can design and build a high performance system to satisfy your requirements. MDi’s systems are high quality with one of the most compact stack heights. Our Hot Runners are dependable, and feature MDi’s innovative nozzle and manifold technology that will allow you to double your capacity without having to increase your injection machine tonnage.

Product Features

  • Interchangeable pins: “any pin in any location”
  • Compact stack height
  • Wiring is internal and protected
  • Maintenance is very easy as pins, pistons, and seals are accessible without having to split the plates
  • All MDi Stack Mold systems are offered with a removable Sprue Bar
  • MDi designs are low maintenance with reduced down time
  • Simple maintenance tools included with Valve Gate systems
  • MDi’s water manifold option makes the installation of a Hot Runner’s multiple water connections easier and quicker
  • Optimum gate vestige quality


Parts made by the use of a Valve Gate usually have the least frozen-in stress, without any sprue, and no visible defects. Valve Gates can yield consistent shot-to-shot repeatability, faster cycle times, good automatic mold operation and better part quality. Valve Gated molds are therefore, ideal for automated high volume production.

In addition to Valve Gate Stack Systems, MDi also offers Single-Cavity Valve Gate systems with only one drop for production or prototype applications. MDi’s Single-Cavity Valve Gates feature the same innovative gating technology used in our multi-cavity Hot Runners.

  • Stack molding requires less space
  • Uses smaller machines, which results in reduced run costs
  • Produce twice as many parts without increasing press size/tonnage
  • Increased output efficiency
  • Fewer machines required
  • Multiple part designs produced simultaneously
  • Save time and money by producing multiple parts simultaneously
  • Reduced waste

A Stack Mold takes advantage of Newton’s third law of motion, in that the opposite force required to inject a single face is now utilized to mold a second set of parts. A Stack Mold can use the same size of machine with only a 10-20% increase in tonnage to offset the force applied by the machine nozzle to the sprue bar.

MDi offers Valve Gate Stack systems in any configuration so that the user achieves the optimum tooling solution for their application.

Hot Runner Systems made in U.S.A

MDi offers high quality, high performance systems that also durable and dependable, delivered on time, competitively priced and feature MDi’s innovative nozzle and manifold technology.

MDi is a world-leading American manufacturer of Hot Runner systems and components with the capability to develop custom and innovative solutions for plastics Injection Molding. Established in 1984, MDi continues to offer experience in the design and manufacturing of complete, internally heated and balanced precision Hot Runner systems, Valve Gate systems, Sprue Bushings, Molding Machine nozzles, Filters, and MDi’s unique system products and controls. All of our components are in-house designed and manufactured in our facility at St. Charles, IL, with a focus on quality and reliability.