3D printing and plastic injection molding | Szmolding.com

 

“3D printing” is a hot topic right now. This new technology has attracted a lot of attention. It opens up many exciting possibilities for cost-effective plastic manufacturing in the future. But what is 3D printing? How does it work? Most importantly, what can we use it for? How does it compare to the time-tested plastic injection molding function? In this blog, we will discuss 3D printing, what it can do and its similarities and differences with plastic injection molding.

1. What is 3D printing and how does it work?
As the name suggests, "3D printing" involves extruding plastic resin into very precise shapes, creating three-dimensional parts with complex shapes one layer at a time. In a basic sense, a computer-controlled machine squirts warm liquid plastic resin into flat layers, which are stacked until the final part is formed. This is why 3D printing is called an "additive manufacturing" process, all flat layers are "add up" to create almost any shape imaginable. 3D printing uses cheap materials and does not need molds or any special tools to make different parts. In addition, since the entire process is computerized, almost all components can be created very accurately.

2. What can 3D printing do?
Simply put, a lot! All you need is the correct computer model of the manufactured part, enough raw materials, and of course a 3D printer. The process is very effective in terms of material usage, wastes very little plastic, and requires minimal finishing work after printing. In addition, since it is a free-form process that does not rely on molds, dyes or other tools, there are no restrictions on the shapes that can be manufactured.

There are limitations to 3D printing, though. First of all, the parts you make can only be as large as the printing area in side of the machine. Also, the thickness of the layers your equipment can produce will create the final precision of the component and its outside surfaces. Finally, most current 3D printers on the market can only create one part at a time, which means it may not be ideal for large-scale production. However, technology is always improving, so many restrictions may almost disappear in the future.

3. 3D printing VS. Plastic injection molding
At SZMOLDING, we specialize in plastic injection molding, which has its own advantages and disadvantages compared with 3D printing. Instead of squirting liquid plastic into free-form layers, injection molding involves forcing liquid plastic into a metal mold, which has been precisely machined into the final outside shape of the plastic part. This process is great for high-volume production, offering cost-effective speed compared with the current 3D printing technology.  However, it can be costly to redesign, machine, and swap out the custom molds and tooling needed for injection molding when it comes to prototyping or small-volume production. 3D printing allows you to make small changes in part design without expensive reassembly, so it is ideal for developing new parts.

Also, because injection molding requires a negative mold, there are real limitations to the shapes and geometries of the parts it can produce. Obviously, once a part is formed, it must be able to be removed from the mold, so certain shapes will not be usable. The use efficiency of injection molding materials may also be slightly reduced, because the parts must be made with redundant drill bits (such as "thimble"), and these parts need to be removed during the finishing process, resulting in plastic waste. Injection molding may also involve more finishing, because the final seam of most parts is a visible seam, the two halves of the mold are together, there are additional mold markings and the thimble we mentioned earlier.

Most importantly, plastic injection molding and 3D printing can complement each other, each with their own advantages and drawbacks depending on the application. 3D printing might be the hot manufacturing technology of the future, but injection molding is in no danger of becoming outdated any time soon. When used together, they offer fast, cost-effective ways to make plastic parts from prototyping and short-run production all the way up to full, large-scale manufacturing with the lowest unit costs possible.

Want to find out which plastic manufacturing method is best for your parts and your needs? Just call us at +86 075583222882 or contact us today to speak with our team. We’ll be happy to consult with you and help you find the best way to handle your production requirements.