Example 1: Mould Filling Simulation of a Jar Lid ....

This is a very simplistic example of how easy it is to cause more problems for yourself during moulding by wrongly choosing one particular gating position over another. A Jar Lid is a very simple component, comprising of a flat uniform top and threaded side region. The mould tool will commonly comprise of many cavities (to produce many lids in one go) and so any problems (and their associated costs) are quite easily multiplied.

Mould Filling Simulation utilising Centre Gating - Ideal

Injecting the Jar Lid in the centre produces the ideal flow front. The part is filled evenly without any surface blemishes. This filling method is also the most efficient, allowing for short cycle times and therefore reduced production costs.

10% Mould Filling	30% Mould Filling	60% Mould Filling	100% Mould Filling

Mould Filling Simulation utilising Side Gating - Problematic

Injecting the Jar Lid on the side could lead to gas entrapments occurring towards the end of flow. This is caused by the thicker 'threaded' region having lower resistance to flow than the relatively thinner lid top. Hence the flow front tends to lead around the sides of the cap and then backfill, causing short-filling, increased cycle time and material burning or surface blemishes on the finished product.

10% Mould Filling	30% Mould Filling	60% Mould Filling	100% Mould Filling