Short Shot

About this result

If a part short shots, the plastic does not fill the cavity. The flow freezes off before all of the flow paths have filled.

A short shot can be caused by:

• Flow restrictions due to long or complex flow paths.
• Hesitation in thin sections.

What to do next

When a short shot occurs, there are many different ways you can try to ensure the part will fill. Before you try one of the methods listed below, check all of the other results, so that you know the exact cause of the short shot.

You can then use one of these methods to improve the likelihood of the part filling:

• Move injection locations to avoid hesitation; this might cause problems in other areas of the part.
• Add more injection locations; this might cause weld lines in unacceptable locations
• Increase mold and/or melt temperature; this will decrease the viscosity of the melt, making it easier to flow through the part.
• Increase injection speed; this can cause greater shear heating, which can decrease the viscosity of the melt, making it easier to flow through the part.
• Increase the maximum injection pressure for this part; this will increase shear heating which can decrrease the viscosity of the melt.
• Change part geometry; if the part consists of a complex and thin geometry, this may be the cause of the short shot. You may need to thicken thin sections, or reduce the complexity of a flow path.
• Select a less viscous material (higher melt flow rate); by choosing a material with a higher melt flow rate, less injection pressure will be required to fill the part.