To minimise the number of components, many plastic parts incorporate a live hinge to link two parts together. This is especially true for packaging systems (lids, closures and DVD cases for example). The largest market is the flip top closures found on personal care and food & drink packaging.
In most of these applications the hinge needs to be folded and formed whilst the plastic still retains the heat from moulding. If left too long, the structure will have formed causing the hinge to crack and split during operation. PCE has developed several products to cater for this market.