Teaching Students About Filament Properties: A Complete Guide

While 3D printing has many educational benefits, many students still have trouble grasping how the choice of material impacts the end result. Weak prints, failed designs, or pieces that melt or shatter too readily are common results of their assumption that all filaments act similarly. Both students and instructors can become frustrated and learn more slowly as a result of this ambiguity.

This guide will show you how to use simple science, hands-on activities, and real-life examples to teach your kids about the important properties of 3D printing materials. In the end, your students will have a firm grasp on the what and the why of the properties of different filaments.

Common 3D Printing Materials to Introduce in Class

1. PLA (Polylactic Acid)

 

In educational and recreational settings, PLA is the ideal filament of choice. Greener than conventional polymers, it gets its sustainability from plant-based materials like sugarcane or maize starch. You won't need a heated bed to print with PLA because its low temperature range (180 to 220°C) is sufficient. In contrast to the unpleasant fumes produced by ABS, it gives off a mildly sweet aroma when printed.

Students can create small engineering prototypes, artwork, keychains, geographic models, and more in the classroom with PLA. The smooth surface and ease of usage of PLA would be great for a student making a model of a structure or a puzzle cube, for instance.

Purchase link: Amazon.

2. ABS (Acrylonitrile Butadiene Styrene)

ABS has more strength and impact resistance than PLA. It needs a heated bed to avoid warping and prints at a higher temperature of approximately 220°C to 250°C. If you want to keep the print environment constant and prevent cracking, an enclosed print chamber is a good choice.

Robotic components, tool handles, and functional joints are some of the many classroom applications for ABS. In the case of a robotic arm, for instance, students can print robust joints made of ABS that will not break even after extensive use.

Purchase link: Bambulab.

3. PETG (Polyethylene Terephthalate Glycol)

With PETG, you get the advantages of PLA and ABS. Compared to ABS, it is less prone to warping and easier to print, although it retains ABS's flexibility and impact resistance. Printing temperatures range from 220 to 250°C, and it stays put on the bed. In addition to being resistant to water, it is food-safe, so it's a great option for containers or components that will get wet. While TPU is the most flexible material, PETG is slightly stiffer than PLA. Printing mechanical brackets, replacement parts, or protective cases is all possible with this printer. The strength and resistance to cracking of PETG could be advantageous for a student creating a wall-mounted bracket or a water bottle holder for a bike.

Purchase link: Overture.

4. TPU (Thermoplastic Polyurethane)
 

TPU is a rubber-like filament that is both elastic and flexible. Since it is soft, printing it at temperatures between 210 and 240°C  necessitates a slower speed. Instead of a Bowden-style system, a direct drive extruder might be necessary to prevent filament jams.

Printing on TPU makes for excellent phone covers, bespoke gaskets, shock absorbers, and wearable tech. Students can learn about elasticity in the classroom by creating their own flexible straps or little bouncing balls. Structure and material qualities come together to form practical usefulness.

Purchase link: Amazon.

5. Nylon

Durability, resistance to wear, and a hint of pliability are nylon's claimed characteristics. It requires a dry, sealed container for storage and prints at temperatures between 240 and 270°C. If nylon becomes wet, it will be brittle and print poorly. Gears, bearings, and practical hinges are perfect applications for Nylon's mechanical strength. Students in a STEM class have the opportunity to print gear trains or sturdy, hinged enclosures that can withstand multiple uses. Use nylon for long-lasting toughness if you're a student creating a gear gearbox or a snap-fit box.

Purchase link: Amazon.

6. Resin

Instead of using filament-based FDM systems, SLA or DLP printers employ resin. It can create prints with remarkable detail and cures when exposed to ultraviolet light. Molds, dental models, jewelry prototypes, and miniatures all benefit from its use. A professional touch, along with a smooth surface and exquisite details, characterizes the prints. As an example of the potential of precision materials, art and biology students can print miniature sculptures or highly detailed anatomical models out of resin.

Purchase link: Amazon.

Important 3D Printing Material Properties to Teach 

1. Tensile Strength and Flexibility

One measure of a material's durability is its tensile strength. Its pliability is the degree to which it can be bent without breaking. PLA's strength is great, but its flexibility is lacking. TPU is pliable and has a gentle feel. Design planning relies on these qualities.

2. How Well It Withstands Heat

Even at low temperatures, some substances can melt or change shape. Near 60°C, PLA begins to soften. Though it requires an enclosed printer, ABS can withstand greater temperatures. Thermal resistance impacts the utilization of parts, and students should be aware of this.

3. Absorption of Humidity

Nylon can soak up atmospheric moisture. The print loses its strength and quality as a result. Water is less of an issue with PETG and PLA. Protect your students' creations by instructing them on proper filament storage and drying.

4. The Look and Feel of the Surface

Various materials produce prints with varying textures. PLA leaves a flawless surface. Matte is a better way to describe ABS. PETG tends to be shiny. Resin delivers crisp details. Artistic creations, models, and miniatures all benefit from these distinctions.

Hands-On Activities to Reinforce Learning

A. Print the Same Object in Different Materials

Use PLA, ABS, PETG, TPU, or Nylon to print a basic model like a 3D cube, hanger, or name tag. All students should receive a sample. Let the kids look at them, compare their textures, and see how hard or flexible they are by lightly pressing on them.

Use queries like, "Which feels soft?" as a starting point. Which one is the most polished? Which one is more powerful?

To explain the difference, a PLA cube might be light and rigid, whereas a TPU cube would bounce back to its original shape when squeezed.
 

B. Bend and Stress Tests

Students should assess the samples' flexibility and hardness by bending them. For example, TPU has the ability to twist and stretch without breaking, PLA has the property of snapping cleanly, and ABS has the property of slightly bending before cracking.

To learn how different materials respond to stress, let students gradually apply pressure. The real-world examples of tensile strength and brittleness are better understood in this way.

Based on their results, let students guess which material would be ideal for a key holder or mechanical lever.

C. Heat Exposure Activity

Show the effects of heat on various materials. To dry, either use a hair dryer or a short soak in hot water. Observe developments with the students. When compared to ABS and PETG, they may notice that PLA components bend and soften more easily. Experiment results demonstrate that PLA does not perform well in heated settings, such as a vehicle dashboard. Questions of thermal resistance and the security of its applications can arise from this evaluation.

D. Moisture Test

In a glass of water, place PLA, Nylon, and PETG samples the night before. Keep an eye out for redness, swelling, or tenderness the next day.

While PLA and PETG don't alter when exposed to water, students may see that Nylon weakens after absorbing water. Use this to talk about what to look for in outdoor or marine-grade materials.

Prompt your pupils to think of examples of similar goods in the real world, such as gardening equipment, swimming goggles, or boat components.

Best 3D Modeling Software for Education

When teaching about different material properties, SelfCAD, an easy to use 3D design software can help by allowing students to design 3D models easily and simulate how different materials might behave. Its simple interface, interactive tutorials, and built-in slicer make it ideal for classrooms. Students can create, modify, and prepare models for printing, all in one platform, making it a great tool for teaching material-based design choices. The video below shows the overview of the software.

Enhancing Understanding Through Projects

Instructing pupils about material properties enables them to make more informed design decisions. It enhances their comprehension of scientific and engineering concepts. It bridges the gap between theoretical study and practical application. Learning takes place on a deeper level when pupils test, observe, and reflect.

Teachers can make this subject interesting and memorable by incorporating activities like conversations, observations, and hands-on projects. The information that students get has practical applications outside of the classroom. Their design, thinking, and problem-solving skills improve.

 

Frequently Asked Questions (FAQs) 

Q1: Why should students learn about the various 3D printing materials?

Students can make more informed design decisions when they have a firm grasp of material characteristics. They learn the importance of flexibility, temperature resistance, and strength in practical situations. Engineering design, critical thinking, and the study of materials are all areas that benefit from this program.

Q2: What is the best filament to start with in a classroom setting?

For newcomers, PLA is the way to go. You won't need a heated bed to print it, and it's safe. It is ideal for making art models, prototypes, and other high-quality prints.

Q3: Is it safe for kids to use resin or ABS at school?

Yes, but proceed with care. ABS emits fumes; hence, adequate ventilation is necessary. You should wear gloves when working with resin, and make sure you use a well-ventilated or filtered environment. Strict safety measures and enough oversight are required.

Q4: What kinds of classroom projects are good for showing material differences?

A flexible phone holder or a heat-resistant bracket are just two examples of the kinds of parts that students can create and tailor their material choices to meet.

Q5: How can educators evaluate their students' grasp of material attributes?

Observation worksheets, quizzes, and practical challenges are all tools that teachers might employ. Instruct the class to select a material and explain their selection. Another great way to demonstrate comprehension is through group presentations or scientific publications.