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Extruding polycarbonate (PC) on the NEXT 1.0 Advanced desktop filament extruder

respiratory hood with polycarbonate face mask

A 3M Respiratory hood with a polycarbonate face mask.

Polycarbonate (PC) is a widely used strong, tough, stiff and durable thermoplastic polymer. Polycarbonate is used widely in construction, eyewear, consumer electronics, food packaging and the automotive industry (headlights, interiors). It can be transparent, be an electrical insulator and is known to have good thermal resistance and very good impact resistance.  There are hundreds of grades of PC varying from filled variants (carbon, carbon fiber, glass, fiber) to blends (PET, PBT) to alloys (with ABS, Acrylics). Inherently polycarbonate may have low scratch resistance and low long term UV resistance but this can be ameliorated by blends or additives (or by applying coatings to the final product). There are optically clear grades specifically for things such as safety glasses and grades that are flame retardant. If something needs to have high strength and impact resistance while being lightweight polycarbonate is often at the top of everyone’s list. If additionally it needs to be an insulator or have high optical clarity it is often the material of choice. Blow molding, injection molding and extrusion are all done with PC. Controversially polycarbonate is manufactured using bisphenol A. Even though many standards authorities consider the material safe for food contact applications there has been a consumer backlash against products in food contact applications that may contain bisphenol A. There are a whole host of polycarbonate manufacturers including Sabic, Celanese, Quadrant, Schulman, ChiMei, Teijin, DSM, Covestro (formerly Bayer Material Science), Ineos, Asai Kasei, Lehmann & Voss, Mitsubishi and many others. Due to this polycarbonate is known under many brand names such as Lexan, Makrolon, and Cycoloy.

Covestro's Makrolon polycarbonate sheets are used in outdoor applications like the cladding for the Allianz Arena

Covestro’s Makrolon polycarbonate sheets are used in outdoor applications such as the cladding for the Allianz Arena.

For many industries PC is a mainstay of their industrial plastics usage. With many grades being made and developed (because the material is so compatible with many other plastics) there is continual development in the Polycarbonate market as well. We’ve noted a high interest in PC from certain customers due to their high usage of the material.  Due to this we’ve been dialing in the material and extruding it on our 3devo and 3devo next.

Drying polycarbonate granules is an absolutely essential step when trying to make filament

Drying polycarbonate granules is an absolutely essential step when trying to make filament.

 

storing polycarbonate granules in airtight containers

We store our polycarbonate granules in airtight containers.

What we’ve found is that drying out polycarbonate before use is absolutely essential. Drying has a huge impact on the process-ability of the material. The surface and the brittleness of the material are adversely affected if the material is not sufficiently dry. Depending on the grade an additives five hours at 110 Celsius is recommended. With some grades longer drying times or drying times at a higher temperature such as 120 may be better.

One of our filament extruders while making polycarbonate filament

One of our test filament extruders while making polycarbonate filament.

 

A spool of PC 3D printing filament made on a 3devo filament extruder

A roll of poly-carbonate 3D printing filament made on a 3devo filament extruder

Our Polycarbonate filament performs well and are waiting to see what our customers will develop with this material.

A Guide To FDM Printable Plastics And 3D Printing Filament

When it comes to 3D printing, we are witnessing a huge wave of development, either in the 3D printing technology or in the use of innovative printing material. The process of producing 3D prints from various materials is generally called Additive Manufacturing (because the object is produced by adding a number of material layers until finish). In the past years, 3D printing has greatly evolved, featuring several new manufacturing techniques. Today, engineers and developers strive to improve 3D printing while making use of the latest technologies launched on the market. The current 3D printing technologies are:

Walt Whitman on spiders, describing their silk as filament.

Overview of different 3D printing technologies, via Windesheim

  • FDM Fused Deposition Modeling
  • SLA Stereolithography
  • 3DP – Tridimensional Inkjet Printing
  • PJP Polyjet printing
  • LOM Laminated Object Manufacturing
  • DLP Digital Light Processing
  • SLS Selective Laser Sintering

Whilst all the above technologies are still under development, each comes with its advantages and disadvantages. The most popular 3D printing method today in terms of affordability, use of technology and 3d print quality is FDM, or Fused Deposition Modeling.

What is FDM?

FDM is a simple, accessible and productive 3D printing technology used for new product development, prototypes and other manufacturing purposes. Since this is an ecological and easy-to-use technology, it is widely used in the transportation and food industry. (We discovered it long ago and have been using it ever since – or something like that)

Walt Whitman on spiders, describing their silk as filament.

Sideview from a FDM 3D printer, via Printspace3D

How does it work?

Specialized software makes possible for the 3D model to be virtually sliced in transversal sections/ layers. The printing technology consists in inserting a plastic filament through an extruder that warms it until to melting. At this point, the melted filament is homogenously applied through extrusion, layer after layer, with high accuracy, in order to manufacture the 3D print according to the CAD pattern.

Walt Whitman on spiders, describing their silk as filament.

How the FDM process works, via Rapidprototyping

Types of plastics used for FDM production

The prime matter used for the FDM technology consists in plastic materials. However, we are not talking about just any kind of plastics. 3D printing requires a special type of material: thermoplastics. There are countless types of plastic materials used to produce filaments for 3d printing:

  • PS (Polystyrene), as a thermoplastic material, can be melted at 100 Celsius degrees. At room temperature it features a glassy state. It can be successfully used for 3D molds with fine details. However, it degrades slow, creating environmental debates.

    Walt Whitman on spiders, describing their silk as filament.

    CD covers are made of PS, via materialrecoveryinc

  • BioFila Linen is a relatively new material used for creating 3D printing filament. This material doesn’t in fact contain any linen fibers, but Lignin, an organic material. The properties of BioFila are amazing. The 3D prints feature a texture similar to linen, yet stronger and more porous-looking like structure.

    Walt Whitman on spiders, describing their silk as filament.

    Organic resources are used, via 3ders

  • PLA (Polylactic Acid) is a fairly strong material. However, it is less flexible than ABS. what’s interesting about PLA is that it’s biodegradable and will corrode in wet conditions. Since PLA is a resorbable composite, it is widely used in tissue engineering and maxillofacial surgery.

    Walt Whitman on spiders, describing their silk as filament.

    PLA is very appropiate for creating detail, via prototypingengineer

  • PA (Polyamide) is used for producing some of the cheapest 3D printing filaments. PA is less brittle than PLA and ABS, thus much stronger. Additionally, it features self-lubricating properties, ideal for gears printing.

    Walt Whitman on spiders, describing their silk as filament.

    PA is tough, stiff and suitable for editing, via alibaba

  • PPSF (Polyphenylsulfone) is generally used in product development due to its high heat resistance. In addition, it is appreciated for the increased mechanical strength and resistance to solvents.

    Walt Whitman on spiders, describing their silk as filament.

    PPSF is a high-performance thermoplastic, via springitalia

  • PC (Polycarbonate) is ideal for complex 3D prints, such as fixtures, prototypes or composite works. It features a flexural and high tensile strength.

    Walt Whitman on spiders, describing their silk as filament.

    Some grades of PC are optically transparent, via superdacha

  • ABS (Acrylonitrile Butadiene Styrene) is a material that delivers mechanical stability and resistance over time.

    Walt Whitman on spiders, describing their silk as filament.

    The famous Lego bricks are made of ABS, via transvorm

The last three types of plastic materials are the most commonly used for the production of industrial quality filaments. Filaments are an excellent prime matter for professional 3D printers. The better the filament quality, the better the 3D print results. Therefore, it is essential that thermoplastics used for the manufacturing of filaments should feature exceptional properties. The filament quality has a direct impact on the heat and mechanical resistance of the resulted prints. Therefore, PLA and ABS filaments are used to manufacture 3D prints for prototype testing. Read more about the differences of these two filaments here.

What are the properties of these materials?

Walt Whitman on spiders, describing their silk as filament.

Printing layer by layer, via capinc

Thermoplastics are heated, formed and finally cooled in infinite shapes. Such materials feature specific properties that make them indispensable for the 3D printing industry:

  • Lightweight (density varies from .9 to 2 gm/cc).
  • Resistant to various temperatures: from -100F up to an astonishing 600F.
  • Thermal and electrical insulation.
  • Adaptable chemistry can turn thermoplastics into objects similar to rubber consistency or as resistant as aluminum.
  • Resistant to solvents at room temperature.
  • Adding metal fibers or carbon to thermoplastics will confer electrical conductibility.
  • Excellent replacements for metal objects, with significant weight savings.
  • Resistant on long term and less prone to deformation, unlike metals.
  • Engineering thermoplastics feature a tensile strength of over 7,500 psi.

Which industries rely on 3D printing and have undergone intense material research?

Walt Whitman on spiders, describing their silk as filament.

3d printing technology helps MX3D to build a bridge of steel in the center of Amsterdam, via inhabitat

Although 3D printing is a relatively new industry, and there is still no mainstream production method, one thing is sure: the speed of development in the field is absolutely breathtaking. Some of the industries that already use 3D printing technology to improve and stimulate progress are:

  • Aerospace industry
  • Architecture industry
  • Automotive industry
  • Commercial products
  • Defense industry
  • Dental industry
  • Consumer electronics
  • Medical industry
  • Mold industry
  • Education

Considering the fact pace of current technologies, industrial techniques and equipment become obsolete very quickly. Whilst many companies are perfectly comfortable to using traditional production methods, many are foreseeing the future and opt for investing their resources to develop using a technology as simple and highly efficient as 3D printing.