How to reduce part cost for injection molding.

Here we are talking about making the final part cheaper, not the tool or mould they come from, which is covered in another article. Basically, the cost of an injection molding is made up of;

Material cost

Surface finish

Cycle time or machine time


And extra work or components

The material obviously is a major dictator of cost. Both the type and the amount. There are thousands of different choices and selecting the right one for your product is a science in itself. Costs of materials vary massively so selecting the right one is key. To make the right choice, you need to understand where and how your part will be used. Does it need to be heat resistant? Flame retardant? Have high impact strength? or just look shiny? Once you know what the part needs to do you will be able to lock down a suitable plastic for it, and if you are not sure you can always ask us. Some materials are quite cheap and some are really expensive so making sure you get the one with the right mix of cost vs. performance is key.

Cycle time includes setup and running time for each part, this is where the manufacturer as overheads are. The longer each part takes to make the more expensive it is for the supplier to produce and the more it will cost you. Cycle time is dictated by the tool design, the type of material and the complexity of the part and therefore the tool. Some materials cool very quickly others take a while. Some tools require and are designed with cooling others aren’t. Complex parts require more complex tools and may take longer to demold. Prototype tools often have manually removed inserts for undercuts. I have seen some big automotive parts take 30 minutes each to mold just because the operator had to spend 20 minutes removing inserts from the part and putting them back in the tool every time. The same is true of some parts and there may be occasions where the part needs to be held in the mould even longer to reduce warping for example. So picking the right material and the right company to build your tools is key. The key here is to reduce complexity as far as possible.

About Start Prototyping

Start Prototyping mainly supply our rapid prototyping service and plastic injection manufacturing for many 3D print companies in the world. Start Prototyping has been engaged in rapid prototyping about 10 years, helping too many designers to turn their ideas into reality. Most of the conceptual prototype of the design has been successfully put into the market and has achieved good benefits. Among them, the most representative metal prototype machining, plastic prototype machining, CNC aluminum machining, Low-Volume Manufacturing, processing technology including CNC machining, vacuum casting, rapid tooling, 3D printing and so on. We have the standard quality inspection process, which is completely in line with the customer’s industrial design. It’s a great honor to be a partner with you. Contact Info Contact:James Yuan Company:Start Prototyping Add: LongGang Village, LongXi Town, BoLuo County, HuiZhou City,GuangDong Province, China Tel:+86-13352636504 Email:[email protected] Web: