What is plastic injection molding and what are the advantages?

Injection molding makes possible mass production of intricate, high performance, tight tolerance parts with very little secondary labor and minimal waste. It is defined as a process of shaping plastic by melting it and injecting it into a predesigned mold.

Below we could see what kind of plastic molded parts we could achieve with injection molding.
Below we could see what kind of plastic molded parts we could achieve with injection molding.
Detailed Parts Including Ribs, Holes, and Bosses
Detailed Parts Including Ribs, Holes, and Bosses
Small or precise plastic Parts with Tight Tolerances
Small or precise plastic Parts with Tight Tolerances
Larger Parts: Car Fender,Car Bumper
Larger Parts: Car Fender,Car Bumper

As known, plastic injection molding has a bevy of advantages and benefits over comparative plastic processing and manufacturing methods. Here’s a look at the top 11 benefits of plastic injection molding.

1.High production rate

There is a reason why plastic injection molding is one of the – if not the most common – technologies for long manufacturing runs: it’s fast. How fast? While the speed depends on the complexity of the mold itself, generally only about 15 to 30 seconds pass between cycle times.

2.Large Volume production

The initial creation of a mold can be expensive, with the cost being a few thousand dollars.   But once the mold is built you can create a very large volume of plastic components at a minimal cost.  For this reason, large production runs using plastic machining can cost up to 25 times more than plastic injection molding.

3.Low labor cost

Injection molding machine typically runs with robot hand to keep operations streamlined and production ongoing, requiring minimal supervision.

4.Easily Automated

Most injection machines could be installed with automated system and automation could be achieved easily.

5.Mimimum Secondary Operations

Plastic injection molding is a process, for the most part, where produced parts need little to no end finishing. That’s because all parts that come out of the mold are about the closest thing to a finished appearance. Yes, the surface finish is really that good right out of the mold! Getting back to benefit No. 3 on this list, here’s another an example of how injection molding creates low labor costs.

6.Minimal Scrap Loss

With the plastic mold well built and molding condition set up, mass production could go on very smoothly and the reject rate could be controlled minimum within 2% depending on specifict parts

7.Tight Tolerances can be maintained

Plastic injection molding is such a precise method that it can fabricate nearly any type of plastic part. There are certain design restrictions, but the molds that are made allow the finished product to be very precise. In fact, accuracy is typically within 0.005 inches.

8.Glass, Carbon, etc. Fillers

One cool benefit of plastic injection molding is that fillers or metal parts can be added to components during processing, reducing the density of the liquid plastic while adding enhanced strength to the finished part.  Plastic injection molding is an ideal process for industries or products where parts need to be strong

9.Molded-in Inserts Available

10.Complex Part Capability

11.Good Decoration possible

Injection molding machines are able to process two or more different plastics at the same time or colorant could be added to achieve colorful products

In general, Injection molding is a such a great technology for mass production though the mold cost is a bit high. It is also useful for finalized prototypes that are used for consumer and/or product testing. Prior to injection molding, CNC Machined parts are much more affordable and flexible for products in the early stages of mold design.

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