High-density polyethene, more commonly referred to as HDPE, is a plastic polymer known for its durability and strength. It is made of synthetic polymers derived from petroleum and mostly composed of ethylene. It is a recyclable plastic that lines your kitchen pantries, medicine cabinets and garbage bins. It’s light yet tough enough to contain everything from cartons of skim milk and economy-sized bottles of laundry detergent to cans of soda and toothpaste tubes.
The advantages of the material include being lightweight, resistant to cracking, impact and chemical damage, drop shock penetration resistance, electrical insulation properties and relatively low cost. HDPE can be recycled into a range of products including furniture components, pipes, containers, laundry detergent bottles and even toys.
In 3D printing, it has recently become increasingly popular due to its superior mechanical properties compared to other materials such as PLA or ABS. It is also 80% recyclable; hence using it in production processes helps prevent nature from unnecessary harm. HDPE could potentially be an exemplary alternative in environmental-friendly production processes.
Making 3D printing filament out of HDPE containers is a surprisingly creative process. In order to create the filament, it all starts with shredding the containers into tiny pieces, then melting them together and forming a thin string-like shape. To make that step easier to relate to, it could be seen as a similar concept to making pasta noodles. After letting it cool, the filament is then wound onto spools and ready for use in any 3D printing project.
HDPE 3D Printing Applications
HDPE is perfect for a variety of 3D printed things due to its durability, low density, and toxicity-free properties. Here are a few such usage examples.
High-density polyethene (HDPE) has a very low density, making it buoyant in water. When sealed and submerged, HDPE is capable of staying afloat due to its low density, regardless of the weight of the object. This property makes it ideal for creating products that can float on the surface — such as floating docks and buoys.
Boats are another example of an HDPE product since the hulls are crafted from this lightweight material. Because HDPE plastic does not absorb water or moisture, these boats remain intact and free from corrosion even after being exposed to long periods of submersion in bodies of water.
Whether it’s a pool party you’re looking to spice up, or a tropical vacation where you want to explore secluded coves, 3D printing HDPE objects can create toys and accessories that are uniquely yours and won’t weigh you down with worries about sinking.
Food containers with vessels
Does your cupboard ever seem to be an empty space in spite of the fact it should be jam-packed with all sorts of containers? The biggest culprits are inevitably plastic storage solutions – Tupperware, containers, lids – that somehow manage to magically go missing. Fear not though; 3D printing is here to the rescue! Your own 3D-printed storage solutions will be non-toxic, non-absorbent and non-dishwasher safe. So not only can you use them to store food but also items like coasters and koozies too. All said and done, hand washing them is the best way to keep these 3D-printed solutions as neat as new.
This is more of an industrial application that should be left to professionals, but we wanted to mention it as an example of HDPE’s versatility as a 3D printing material because it is improving the medical area.
HDPE has become a staple material in the medical industry for its proven non-toxicity and resistance to water absorption. Certified by the FDA which makes it an ideal choice for containers for food, supplies, and other materials. But recently, industrial medical supply manufacturers have been experimenting with using HDPE to create even more complex and invasive medical supplies such as bone replacements.
This is because HDPE is known for its strength and lightness, making it the ideal material for high-tech medical practices. Additionally, its affordability and sustainable nature further drive down costs for patients, making this high-end medical technology available to everyone.
HDPE filament is a popular material used in 3D printing because of its unique properties that make it suitable for various applications. Below are some of the common uses of HDPE filament in 3D printing:
- Large-scale prints: HDPE filament is known for its high strength-to-density ratio, making it an excellent material for printing large objects. It can withstand a lot of stress and pressure, making it an ideal material for printing objects that require high durability.
- Chemical resistance: HDPE filament is highly resistant to chemicals and can withstand exposure to acids, bases, and other corrosive substances. This makes it an ideal material for printing parts that will be exposed to harsh chemicals.
- Food-grade prints: HDPE filament is considered a safe material for printing objects that will come into contact with food. It is non-toxic and does not contain harmful chemicals that can leach into food, making it a popular choice for printing kitchen tools and utensils.
- Outdoor applications: HDPE filament is resistant to moisture and UV light, making it suitable for printing objects that will be exposed to the elements. This makes it an ideal material for printing outdoor fixtures and fittings.
- Filament recycling: HDPE filament is easy to recycle, and can be used multiple times, making it an eco-friendly material choice for 3D printing.
High-Density Polyethylene (HDPE) has several disadvantages when used in 3D printing, including:
- Heavy warping: HDPE is prone to warping when exposed to high temperatures, particularly during the printing process. This can result in parts with poor dimensional accuracy and reduced strength, making it difficult to produce precise, high-quality objects.
- Lesser self-adhesion: HDPE does not bond well to itself, which can make it challenging to produce complex objects with multiple parts or intricate shapes. This can result in weak, brittle objects that are prone to breakage.
- Shrinking issue: HDPE is known to shrink as it cools, which can result in parts that are undersized or distorted in shape. This can cause problems with dimensional accuracy and can make it difficult to produce parts that fit together precisely.
HDPE in 3D Printing
It is great news that 3D printing with HDPE, or high-density polyethene, is a standard FDM printing process. Yet, it brings an unfortunate challenge in the form of difficulty; HDPE has proven to be a challenging material to work with in comparison to other filaments.
When it comes to 3D printing with HDPE, there is no need to break the bank on a new machine – as long as you already own a printer that is compatible with ABS. In most cases, the same settings used for ABS coincidentally can be used for HDPE 3D printing projects, making it much more accessible for your existing hardware. Plus, with ABS being one of the most popular types of filaments on the market today, you’ll have plenty of options to choose from if you are searching for a machine that will enable your creative vision.
High Nozzle Temperature
Using HDPE as a 3D filament requires greater accuracy of extruder temperature than some other materials. Without this attention to detail, the plastic might start emitting an unpleasant and toxic smell due to the higher temperatures between 230 – 260°C needed for the plastic to flow consistently. Therefore, it is very important to ensure your extruder is within this range when using HDPE as a filament and be sure not to exceed the limit.
Heated Print Bed
It is vital to ensure the material is kept stable and warm throughout each printing process. Printing this type of filament on a heated bed can be a great help in overcoming its self-adhesion and shrinkage issues when cooled. This helps to give your object’s foundation more stickiness, ensuring the printed item holds together properly.
I am Ganesh Divte. I work as a Quality Assurance Engineer at Dhruvtara WireTech PVT LTD. I have experience in SLS, DMSL, FDM, and SLA additive manufacturing processes. I am very enthusiastic about additive manufacturing and its potential to change the way we manufacture products. I believe that Additive Manufacturing has the potential to revolutionize the manufacturing industry and make it more efficient and sustainable.