Objective

The objective of this work package is to conduct research into techniques for 3D printing of plastics and composites, and to realize applications for this. There are many different commercially available techniques for printing these materials, each with unique strengths and weaknesses. The following of these techniques are for the 3D Print Compass in scope:

• Powder bed fusion (PBF), in which parts are manufactured by fusing local material together in a volume of powdered plastic. PBF systems for plastics are relatively accurate, offer a very high degree of design freedom, and can produce cost-effectively. This makes them suitable for the production of parts in small to medium series. A PBF system suitable for serial production experiments is available at the Drachten Innovation Cluster.
• Fused deposition modeling (FDM), which involves printing by passing plastic wire through a heated extruder. This is one of the simplest techniques for 3D printing. Obtained parts have a relatively low accuracy, but also a very low cost price. By mixing plastic with fibers (such as glass or carbon), composites can be printed. FDM systems are available at many of the project partners, but special systems that can also print composites are available at Philips Drachten and Binder3D.
• Material jetting (MJ), in which material is printed drop by drop in liquid form and then directly cured into a solid material. Some MJ techniques are able to print plastics in full color, sometimes with transparency and local variations in material properties. Therefore, this technique is very popular for creating prototypes and demonstration models. Philips Drachten has a number of MJ systems that are used almost exclusively for prototypes.

Project activities

Activities related to 3D plastic and composite techniques are as follows:

• PBF techniques: Develop knowledge of the possibilities of PBF techniques for printing various materials, such as rigid materials (glass bead-filled plastics) and flexible materials (ie rubber-like materials). In addition, gain experience with the use of these techniques for serial production, with a focus on process stability and standardization with regard to the production process, as well as the realization of associated applications.
• FDM techniques: the use of FDM for the fast and inexpensive manufacture of very small product series as well as special tools (such as fixtures), with the emphasis mainly on the 3D printing of composites.
• MJ techniques: developing knowledge of the possibilities of printing silicone rubbers for the creation of prototypes suitable for applications related to food and medical purposes.

Because the design of parts is linked to the design freedom of the different 3D printing techniques, there will be interaction with the work package Design Methods.

Business Case

Development in the field of plastic and composite printing offers the manufacturing industry in the Northern Netherlands the following opportunities:

• Techniques suitable for series production make it possible for companies to produce smaller series cost-effectively. The flexibility that 3D printing has as a production technique also makes it possible to shorten time-to-market (because production tools such as injection molds are not required), quickly convert production processes, and serially manufacture unique, personalized products. The high degree of design freedom compared to the more conventional production techniques such as injection molding can be simultaneously used to make more complex, innovative parts/products.
• 3D-printed rigid plastics (including composites) can be used for the fast and cheap production of tools such as fixtures and grippers.
• The use of 3D printing of silicone rubbers is of great value for the development of silicone parts and products for applications involving contact with food, or for applications in the medical market. This is because 3D printing of silicone rubber can be used to quickly and cost-effectively manufacture prototypes.