It is important to select the correct plastic so that the print turns out to be of high quality. This is increasingly becoming difficult as the market has seen the emergence of new materials. When it comes to FDM 3D printing, the ABS and PLA were historically the principal two polymers. Their initial dominance is now almost the matter of past. Other polymers now increasingly play an important role in plastic printing. Both polymers and composites are now being adopted for printing. The main polymers in this context are PLS, PC, ABSD, Nylon, and TPU (Flexible).
A standardized system must be followed to select the correct type of plastic for printing. The materials are graded along three principal categories: process, mechanical performance, and visual quality. The properties of the polymer must be known. The ultimate material choice depends on what the user actually wants to print. Decision must be taken based on these parameters. Other factors are speed and cost.
The first is how easily the substrate could be printed. This depends on factors like maximum printing speed, flow accuracy, ease to printer feed, failed print frequency, and bed adhesion. The visual quality is also important. It is how the finished product appears.
Maximum stress is yet another important factor. It is the stress any object can undergo when it is stretched prior to breaking. The impact resistance is the energy required to break any object with sudden impact. Layer adhesion is another vital factor. It defines how good the adhesion existing between the material layers is. This is associated with isotropy or all direction uniformity. Better layer adhesion equals better isotropy of the object. The heat resistance describes the maximum temperature any object can sustain prior to softening and then deforming.
Based upon such parameters, it can be deduced that the easiest printing is done on the PLA polymer. Visual quality is excellent. The material is rigid and strong. One negative point is that the plastic is brittle. This is the reason ABS is chosen over PLA when the print needs to be tough and must be resistant to higher temperatures.
A softer polymer is PET. It has a number of interesting properties but has its share of drawbacks. In contrast, nylon has excellent mechanical properties. It possess best impact properties among non-flexible filaments. TPU is utilized for mostly flexible applications.