Является ли литье под давлением разновидностью аддитивного производства?

Injection molding and additive manufacturing are two different manufacturing processes that are often compared. But is injection molding actually a form of additive manufacturing? As a professional производитель литья под давлениемЯ помогу вам это выяснить.

Is injection molding additive manufacturing?

The short answer is no, injection molding is not considered a type of additive manufacturing. While both processes involve building up material to create a part, there are some key differences between them.

Additive manufacturing, also known as 3D printing, is a process where a part is built up layer-by-layer using a digital model. The most common additive manufacturing technologies include fused deposition modeling (FDM), stereolithography (SLA), and selective laser sintering (SLS).

In contrast, injection molding is a manufacturing process where molten plastic is injected under high pressure into a mold cavity. The mold is created beforehand based on the desired shape of the final part.

So while both additive manufacturing and injection mold build up material, the key difference lies in how that material is deposited and formed:

• Additive manufacturing deposits material layer-by-layer based on a digital model
• Литье под давлением injects molten plastic into a pre-formed mold

Because of this fundamental difference in process, injection molding is considered a separate manufacturing method from additive techniques like 3D printing.

Comparing additive manufacturing and injection molding

Beyond the core process difference, there are several other factors that set additive and injection molding manufacturing apart:

1. Speed

Injection molding is a very fast process capable of producing hundreds or even thousands of identical parts per hour. The injection molding machine can produce a part in less than a minute once the mold is ready.

In comparison, most additive manufacturing techniques build parts relatively slowly, one layer at a time. Parts can take hours or even days to 3D print depending on their size and complexity.

2. Upfront costs

The molds required for injection molding can be extremely expensive, often costing upwards of $100,000 or more. This means there is a very high upfront investment for injection molding.

Additive manufacturing has relatively low upfront costs in comparison. A desktop 3D printer and materials might only cost a few thousand dollars to get started. No tooling is required since parts are built directly from a digital file.

3. Design freedom

One of the major benefits of additive manufacturing is the unprecedented design freedom it provides. Extremely complex geometries with interior voids and lattice structures are no problem.

Injection molding design is restricted based on the limitations of pulling a solid part out of a mold tool. Simple splits in the tooling can enable some forms of undercuts, but in general the part design possibilities are more constrained compared to 3D printing.

4. Post-processing

Additively manufactured parts often require support removal and sanding to smooth out the layered surfaces. Additional post-processing like vapor smoothing or dyeing can further improve part appearance.

By contrast, injection molded parts can be ready for use straight out of the mold with no post-processing required. The one exception might be parts that need additional decorating techniques like pad printing applied.

5. Production quantities

Thanks to its fast cycle times, injection molding really shines for mass production with hundreds, thousands or even millions of identical parts produced. Molds are typically designed to last for 100,000+ cycles.

Most additive manufacturing is better suited for short run production due to the relatively slow build speed. Of course, with the high costs of injection molds, 3D printing can compete on cost at lower volumes.

Is injection molding a hybrid additive process?

In some cases, additive manufacturing is combined with injection molding to create what are called “hybrid manufacturing processes.”

For example, one emerging application is using metal 3D printing to manufacture injection molds with conformal cooling channels. This can enable faster, higher quality injection molding with reduced cycle times.

So while the core injection molding technique does not count as additive manufacturing, integrating 3D printing into the mold-making workflow represents one type of hybrid approach.

The role of additive in injection molding

As highlighted above with hybrid tooling methods, additive manufacturing can play an important role in the broader injection molding workflow even if the core molding technique remains quite distinct.

Here are some examples where makers use 3D printing alongside or in support of injection molding:

• Prototypes – Quickly test concepts or evaluate designs fit and function using inexpensive 3D printed parts before investing in full injection molded production.
• Bridge manufacturing – Shift to 3D printing for lower volume production in between injection molding production capability. Helpful to extend product lifecycles on a small scale.
• Custom end-use parts – Mix of lower volume 3D printed parts and higher volume injection molded parts enables mass customization.
• Molds & tooling – As mentioned, use additive to manufacture complex injection molds to improve quality and throughput.
• Fixtures – Print custom fixtures, jigs and guides using desktop printers to aid injection molding setup and output.

In essence, additive provides complementary capabilities that extend and enhance injection molding across the product life cycle.

The two manufacturing methods work hand-in-hand. So claiming injection molding as additive would diminish the differences that enable injection molding workflows to become more agile and responsive from start to finish.

Conclusion: injection molding complements additive manufacturing

While additive and injection molding both produce plastic parts, they leverage fundamentally different approaches to build up and consolidate material. Core factors like speed, cost, scalability and design freedom clearly distinguish the two methodologies.

Rather than positioning injection molding as a subset of additive, it is better framed as a complementary process enhanced by 3D printing. Makers leverage additive techniques to extend capabilities for prototyping, tooling, bridge production, customization, and fixture creation in support of scalable injection molding.

The synergy between the two technologies creates production systems that are flexible and responsive across product life cycles – from early stage development to end-of-life. Blending additive and injection molding is at the core of agile advanced manufacturing strategies as technology increasingly shapes the factory of the future.