What is Injection molding, how does it work, and what is it used for?
Injection molding is a formative manufacturing process used to produce parts. The process is done by injecting molten material (usually melted plastic) into the heated barrel of a mold, where it is mixed with a helical shaped screw, then injected into the mold cavity, and left to harden as it cools. The part will take the form of the mold’s cavity when done and then can be ejected and the process repeated. In this blog, you will get to know about Benefits and Limitations of Online Injection Molding.
This is a different technology rather than the additive (3D printing) or the subtractive (CNC machining) manufacturing to where the solidification and flow of material during injection has a huge impact on the design restrictions. Sheet metal services are more cost-effective than CNC machining services when it comes to metal components with uniform wall thickness.
Online Injection molding is used throughout the world for applications in engineering and consumer products. In fact, almost all the plastic items around you were manufactured using this type of technology since very high volumes of identical parts can be produced at a low cost. However, because injection molding requires special custom tooling, the startup costs are relatively high.
Benefits and Limitations of Injection molding
Like everything else, online injection molding has its good points and its bad. However, whether or not the good qualities outweigh the bad depends entirely on the type of project you are working on.
Benefits of Injection molding
- Extremely high productivity
To beat the high cost of machine set up and mold creation, 500 units or more should be produced.
- Great visual appearance
A key benefit of Injection molding is finished products can be produced that needs little to no finishing.
- High volume plastics manufacturing
Because a single mold can produce multiple parts, numerous identical parts can be produced per hour.
- Great tolerances and repeatability
The process of Injection molding can produce identical parts repeatedly.
- Wide range of materials
Most thermoplastic materials and some silicones and thermosets can be injection molded.
Limitations of Injection molding
- Costly design changes
Once a design mold is manufactured, it can be quite costly to modify it; you may as well create a new mold from scratch.
- High start-up costs for tooling
Since each geometry requires a custom mold, start-up costs for tooling are very high.
- Compared to other technologies it has longer lead times
Parts created with a 3D desktop printer can be ready overnight, 3D printing systems may take 3 to 5 days, and CNC machining typically takes 5 to 10 days, where the turnaround time for injection molding may take as many as 6 to 10 weeks.
Examples of Injection molding products
Out of everything you currently see around you, at least some of the products were manufactured using injection molding. Parts made by injection molding may be recognized by the following:
- Throughout the part, there may be a relatively uniform wall thickness;
- The hidden side may have witness marks;
- And the part may also have a parting line’.
A good example of injection molded parts is Lego bricks, which are very recognizable. ABS is used to manufacture these parts since this material has excellent moldability and high impact resistance. Molds used to produce these parts can typically produce 120 million Lego bricks.