The number of molds on the floor of a shop can vary, depending on the size of the processor. For example, a small shop with a few injection molding machines could have a few select molds for customers.
The number of molds a shop may have can vary from hundreds to thousands, depending upon whether they are high mix and low volume, how large they are and how many presses they have. For example, the number could easily be between 200 and 400 molds for an average molder with $30 million in annual sales.
The same example could hold true for any process, including rotomolding, compression molding and thermoforming.
Typically, an injection mold can cost as little as a few thousand dollars to as much as a few hundred thousand dollars. Many things contribute to this cost with the biggest factor probably being the complexity of the part as well as the size of the part.
This can be deceiving because a very simple looking part could be very difficult to build a mold. One reason for that could be because the mold has an undercut that will require moving parts in the mold to move out of the way allowing the part to be ejected freely when the mold opens.
A typical injection mold can take a few weeks to produce. Several factors can impact the time, including the supplier’s backlog, resources available, the complexity of the part and the complexity of the mold design. This carries through other processes as well.
Typically the customer owns the mold — after all, they pay for it. So a key challenge for toolmakers is protecting the creative designs they develop when solving problems for their customers. When a particular mold design works on one type of component, often it solves a similar problem with another component for another customer.