Hot Runner Injection Molding Tool

Used when you have a high volume of parts to produce. Hot runner Injection Molding keeps the plastic in a melted stated whilst the molded product is being cooled to solidify.
The major advantage is that the plastic that is held in the runners can be used with no wastage during the molding cycle.
Whereas within the cold runner system the plastic material in the runners is solidifies during the cooling phase and has to be discarded before commencing the next cycle

Advantages of hot runner injection molding:

• Part cost is the lowest possible per piece.
• Materials cost savings - no runner material to regrind or reprocess
• Quicker cycle times - no runners to clean
• Reduced cycle time and therefore reduced energy costs
• Compact machines – can run less shot material in the runners at any one time
• Other Advantages
• Can run low injection pressures
• Can run low clamping pressures
•  No nozzle freeze

Hot Runner Molds offer Precision Molding:

Hot runner mold tools are often employ needle valve nozzles, which can be activated with precision using computer controlled timing.
This gives you the ability to produce:

• Multi-Cavity Molds – cavities with differing shapes and sizes
• Each cavity can have a different different pressure and the valve can be opened and closed at different times, creating different conditions within each cavity
• Parts which are assembled together produced within one mold tool
• The weld line can be located to a non-critical area of the mold

Disadvantages of hot runner systems:
Hot runner molds are more expensive then cold runner molds because they are more complex than cold runner molds

• High start-up costs.
• Increased operational set up time. 
• Higher maintenance costs mainly due to:
• Wear
• Breakdowns
• Heating element failure
• Spillage
• Complex heating controls