Purchasing plastic parts by injection molding or machining

Developing injection molds or CNC , two main factors need to be considered , they are lead time and total product quantity .

Building injection mold takes much longer than Machining plastic parts. That's one of the attractive elements of machined parts : there is no tooling, so you can make a single part in the span of hours or a day or two days. The problem is that the unit price is expensive.

Machining generally involves the cutting, milling, grinding and other processing processes of metal or plastic materials, with high machining accuracy and surface quality, but relatively low machining efficiency, and requires a large amount of tooling and tool preparation time. Therefore, in terms of time, machining may be more suitable for the production of small batch, high-precision, and complex shaped parts.

With injection molding, it will take a long time to achieve the sample at the first time . The second part takes just seconds.

Injection molds take a long time because of the amount of machining required for injection mold plates . Typically they are made by high-speed cutting of hardened tool-grade steel. The mold is made of many different mold plates (such as Cavity , Core ,A plate ,B plate , Ejector plate, slider and so on . ), and tolerances are extremely tight: typically one half of a thousandth of an inch, or even less.

Specifically, injection molding is a fast and efficient plastic processing method suitable for mass production of structurally simple parts. In terms of output, injection molding can produce a large number of plastic products in a short period of time, and the production cycle is short, suitable for large-scale production.

Below is a simple schedule to provide a general idea of how much time a new mold building , 1-3 months is not an uncommon length of time for a durable mold made to last hundreds of thousands or millions of cycles.