Shot Sleeve Design
The #1 consideration in shot sleeve design should be a heavy wall, at least 1-1/2 inch and
preferably thicker for machines 200 tons and over. A heavy wall lessens deformation, adds strength and stability and provides a good heat sink to the stationary platen. Heavy wall sleeves also
accommodate the drilling of internal water cooling holes around the pour hole area. Thin walls, 3/4 inch and under, are a detriment. They promote pour hole washout and contribute to tip sticking. Also they will bow and produce shot misalignment.
The exposed length of the shot sleeve should be short, having as much as possible in the cover half and the stationary platen. If the stationary platen needs to have an adaptor hole to
accommodate larger sleeves for longer life it would be a wise investment.
The shot sleeve bore should have a small chamfer at the die end to protect the corner. A chamfer at the pour hole end helps start a new tip and prevents lube being scraped off as the tip moves forward.
The pour hole should have a chamfer around the base to reduce stress riser points. Also it should be designed so that 1/2 to 2/3 of the tip body is engaged in the sleeve. This gives a more secure engagement during the critical starting stage and aids in alignment. A rectangular pour hole is more expensive than a round conical opening.
Next: Trouble Shooting-Shot Sleeve and Plunger Tip Failure