Oct 28/20

5 Advantages of Using Injection Molded Parts

Blow Molding, Design Services, Manufacturing Services










Increasing regulation and interest in lowering carbon emissions has spilled into the realm of automakers, who are trying to reduce gross vehicle weight. This in turn has resulted in many automakers switching to plastic injection molded parts where they can.

What are some of the advantages of using plastic over metals? Why injection molded plastic instead of other machining methods like 3D printing or subtractive processes?

We’re going to cover why injection molding is your solution to lower gross vehicle weight and a more sustainable future. Keep reading to see how plastic injection molding can do that and more.

1. Low Scrap Rates

Compared to traditional subtractive processes like CNC machining a sheet or billet of plastic, injection molding produces much lower scrap rates. While 3D printing has still lower scrap rates, it’s more suited to low quantity part orders.

The main waste of injection molding comes from runners, sprues, gates, and any “flash,” or overflow, areas. What do you do with that waste? More on that next.

2. Recyclable

There’s a benefit to thermoplastic waste that you don’t have with metal scrap, as well. It can be remelted, reformed, and recycled to complete an in-house recycling loop.

A CNC machining shop generally isn’t going to melt down their own metal and create new billets. Thermoset materials like epoxy resin, once cured, will burn rather than melt when reheated.

Thermoplastic, on the other hand, will handle melt cycles better, which is the basis for injection molding. Even a CNC shop that is cutting a thermoplastic piece probably wouldn’t recycle their waste into a new billet, instead opting to send it to a recycler.

3. Economy of Scale After Initial Costs

It does take considerable time and cost on the initial prototyping and tooling phase, requiring 3D printing or CNC machining for the prototype piece and mold. Although, the economy of scale and lack of labor costs more than makeup for the initial cost of making the prototype and mold.

If you can mold eight parts per cycle and get two cycles per minute, you get 7,680 parts per 8-hour shift from a single mold. With only four molds, you bring the production time of 1 million pieces down to about one month of production.

That being done with minimal labor, compared to CNC, and the mold is ready for millions of cycles more. Most cycle times for a simple product are within 1-5 seconds, much lower than our example.

4. Reproducible Quality

While CNC machining produces amazing quality, there is more variability in CNC machining or 3D printing to injection molding. When it comes to surface quality, injection molding beats out 3D printing.

The simple matter of the quality is that as long as the mold is good, you’ll get veritable clones of a product with no variation during the production lifetime of the project.

5. Design Flexibility

With custom injection molding you can have an incredible variety of materials and design features. A part can have a rubberized and textured side with a rigid backing. You can also have different colors for different options—for cars, that means variation on interiors and textures.

The Best Choice: Injection Molded Parts

It’s clear that for global size projects, you need a global leader in injection molded parts. Mayco International has over a million square feet of manufacturing space with more than 5,000 employees. With headquarters in Sterling Heights, Michigan, Mayco International is a Tier 1 supplier in 47 plants across seven countries, worldwide.

Are you looking to perform your injection mold design, tooling, and production under the same roof? There’s no reason to look anywhere other than Mayco International, get in touch today!