Can plastic injection be replaced with 3D printing ?

The development of small quantity but diverse plastic products has gradually becoming a trend, and the trend of 3D printing has also become popular. People often ask whether 3D printing can be replaced plastic injection?

Both 3D printing and plastic injection can be used in the manufacturing of plastic products, but the practical application is quite different. When evaluating whether a plastic product should be manufactured by 3D printing or plastic injection, let us first understand the differences between these two processes:

1.Differences in principles of the manufacturing process
The principle of plastic injection molding is like making chocolate. After heating and melting the raw materials, pour them into the mold, and then demold after cooling, and the finished product is completed. You can also add different color pigments to the material to make chocolates of different colors.
The biggest difference of 3D printing from plastic injection is that it does not require a dedicated mold, just like stacking building blocks, which are stacked layer by layer. Because there is no restriction of the molding mechanism, the creativity in product design is virtually unlimited, and products of any shape can be achieved. For example, 3D printing can produce closed hollow products, but plastic injection cannot.

2.Differences in production efficiency
Although 3D printing can save mold costs, its mass production capacity is far lower than plastic injection. For a product the size of a pencil holder, 3D printing takes at least 2 hours to produce, while plastic injection takes less than 2 minutes.

3. Differences in the detail of appearance
Since 3D printing is stacked layer by layer, there will be fabric-like fine lines on the surface of the product. The plastic injection can achieve a specific texture or mirror-like smooth product surface.

4.Differences in structural strength
Injection molded products are usually more resistant to drops and impacts due to the tighter combination of plastic raw materials, while 3D printing is relatively fragile.

5.Differences in the costing structure
In the initial development cost of plastic injection, mold costs are relatively high, but raw materials and molding costs are low, while 3D printing is a one-time custom cost, and a product may cost several thousand Taiwan dollar to tens of thousands of Taiwan dollar.

Simply put, 3D printing is a proofing process, and plastic injection is a mass production process. If you want to create a unique product, you can choose 3D printing, but if you need mass production, you need to choose plastic injection.
The current 3D printing technology cannot replace the mass production capability of plastic injection. Therefore, the foreign customers of 3D printers on the market are also produced by plastic injection. But if you only need a very small amount of finished products, or need to verify the product design, 3D printing is a good choice.