Choosing Materials for Your Prototype – Part I

Stratasys is the leader in additive manufacturing and 3D printing machines.  Their 3D printers are based on two different technologies to create 3D parts.  The most popular technology, based on worldwide sales, is Fused Deposition Modeling (FDM).  The second most popular technology is PolyJet™.   These two technologies use different types of raw materials to create 3D printed parts.

FDM produces parts made of thermoplastics.  Thermoplastics have the characteristic of becoming malleable when heated and then becoming hard when cooled.  The FDM process produces 3D printed parts that are chemical resistant and perform well under mechanical stress and temperature variations.  The parts produced with this process are used for concept models, direct digital manufacturing, functional prototypes, end-use parts, visual models, manufacturing tools, engineering test models, low volume production, high temperature parts, jigs, and fixtures.

Currently, there are 11 thermoplastics to choose from using Stratasys FDM technology.  Each of these materials have a target use.   Thermoplastic materials are grouped into three categories: standard, engineering, and performance.

  • The standard category of materials are all variations of ABS plastic and include: ABSplus, ABS-M30, ABS-ESD7, ABS-M30i, and ASA. The 3D printed ABS parts are approximately 80% of the strength of their injection molded ABS counterparts.  The target uses of the standard category materials depend on your required degree of durability, UV light resistance, semi-transparency, and need for static dissipative parts.
  • The engineering grade materials used in FDM are harder and can handle higher temperature. The materials include: Polycarbonate (PC), PC-ISO, and Nylon 12. Part created with these materials are harder and are resistant to higher temperatures.
  • The performance material bundle includes materials that offer the highest heat resistant, best chemical resistance and tensile strength of all the thermal plastics.

PolyJet™ produces parts made of UV cured polymers.  The process is much like an ink jet printer; however, the “ink” is one of 20 different liquid polymers.  The PolyJet process can create parts not available through other processes. Do you need a transparent part?  Do you need a rubber like part?  Does your part need to be in color?   Or do you need a combination of all three?  PolyJet applications include but are not limited to High resolution concept models, low volume over-molded parts, manufacturing tooling, blow molding, and patterns for urethane castings.

The material properties for UV cured polymers are categorized into seven categories that each represent a physical attribute:

  • High temperature
  • Transparent
  • Ridged opaque
  • Simulated polypropylene
  • Rubber-like
  • Bio-compatible
  • Dental materials.

The digital PolyJet process allows you to create customized materials by merging materials from the seven categories.

There are many material options that fit in either one of the seven PolyJet categories or the three FDM categories.  The key is knowing what material will be used in your end product and then choosing a prototyping material that reflects characteristics of the end product.  This post begins a series where we will discuss materials used in FDM and PolyJet technologies in detail.  In part two, we will focus on the materials used in the FDM process.

If you know the characteristics of material you need, you can always talk with one of our 3D printing experts who can help walk you through the process of selecting the right material for your prototype.  Contact Prototyping Solutions for more information on material selection or 3D printing in general, including prototyping, and learn more about this vital process.

Click to read more posts in our series on choosing materials: