Thermoplastic elastomer
TPE overmould
A second shot bonded onto a rigid substrate. A failed bond scraps the substrate with it, so one defect destroys two parts worth of work.
Typical scrap rate
4%
Yield multiplier
1.0417x
Effect at 1,000 units
At 1,000 units it adds $0.18 to a $14.13 landed unit, the highest of the six, because the scrap takes the first shot down with it.
Notes
An overmould failure destroys the substrate with it. The first shot has already been moulded, cooled, inspected and loaded into the second tool, so a bond failure at the second shot writes off every operation that came before it.
That is why 4% on a two-shot part is not comparable to 4% on a single-shot part. The percentage is the same and the money is not: the scrapped unit carries two tools worth of cycle time, not one.