3D printing, also known as additive manufacturing, started back in the 1980s using plastic. Today, 3D printing materials include food, ceramics, paper, biomaterials, and metal, but plastic remains the most widely used material.
According to 3D Printing Industry, plastics typically used in 3D printing include nylon, or polyamide, a strong, flexible and durable plastic material, and ABS (acrylonitrile butadiene styrene), a toughened co-polymer. PLA (polylactic acid) is a bio-degradable plastic material that has gained traction with 3D printing, although it is not as durable or as flexible as ABS. It can be used in resin format for digital light processing (DLP)/Stereolithography (SL) processes as well as in filament form for the Fused Deposition Modeling (FDM) process.
With so much attention surrounding all things 3D, some industry observers believed that 3D printing with plastic would eventually replace traditional manufacturing. But according to the Plastics News article, 3-D Printing: The Hype is Shrinking, but the Market Is Still Growing, 3-D printing hasn’t replaced injection molding, or any other traditional manufacturing process. The article explains that while the consumer market failed to live up to its hype—desktop 3D printers in every household—the industrial market is still growing and experiencing technological advancements. Nevertheless, injection molding has significant economic advantages over 3D printing for manufacturing high-volume, low-complexity parts, although 3-D printing works well for low-volume, high complexity parts.
How far does 3D printing have to go to catch up to injection molding? Another Plastics News article says the injection molding industry is outperforming the overall industrial average, experiencing strong gains in both new orders and production levels, and increasing its number of employees.
One of the keys to success in the injection molding process is quality control and testing of the raw materials prior to manufacturing. Injection molded parts are usually relatively small, high in shape complexity, high in strength, and demand moderate to close dimensional tolerances. Torque rheometers are used to help meet those quality control demands.
Torque rheometers with laboratory mixers and laboratory extruders are down-scaled production machines which enable the simulation of production processes in a lab environment. This measuring method allows testing and comparing of materials close to production conditions. A modular torque rheometer can be equipped with different measuring sensors such as mixers, single- or twin screw extruders. Simulating industrial polymer processing on a laboratory scale, relevant process parameters such as temperature, pressure and screw speed are measured and help to understand and optimize the respective system.
To learn more about polymer processing, check out our five-part webinar series on general extruders and mixers for characterizing and formulating your polymer materials using rheology, viscometry, mixing and extrusion technologies.
Here are links to the full series:
- Extrusion Rheology – Usage of the Torque Rheometer
- Twin Screw Compounding – Introduction and Scale-Up
- Downstream Options for Extrusion
- Mixer Test – A Versatile Tool for Polymer Processing
- MIM/PIM Application – Mixer, Compounding, Rheology
I’ve never really seen 3D printing as a threat to traditional manufacturing, but as a valuable addition to the technology. You made a good point when mentioning injection molding and quality control. It’s true that 3D printing isn’t able to achieve the same results. I also don’t think it will ever replace something like plastic extrusion manufacturing.