Home » All Material » Plastic in 3D Printing

Plastic in 3D Printing

.Plastics in 3D printingPlastics are the most common 3D printing materials but what do we really know about them? What are the differences between each of these plastics?

When we start using 3D printing technologies, it is important to know with which material we want to work and what characteristics we want to give to the created object. Choosing the right printing material can be more complicated than you think, especially with regard to plastics.

Each 3D technology is based on different types of materials:

  • the deposition of molten material is based on the use of filaments,
  • stereolithography employs liquid photopolymer resins
  • laser sintering requires thermoplastic powders.

Melt deposition technologies are best known for using plastic materials. They come in the form of a filament spool that is placed on the 3D printer. There are many varieties of plastics with different characteristics for each project.

Plastics in 3D printing – FDM / FFF

Plastics in 3D printing ABS

It is the flagship material of Lego bricks, which is also widely used in car bodies, household appliances and in many roll-over applications. ABS, that is, acrylonitrile butadiene styrene, is the most widely used plastic in the industry. It belongs to the family of thermoplastics or thermal plastics and has a base of elastomers based on polybutadiene which makes it more flexible and resistant to shocks.

ABS has a printing temperature between 230 ° C and 260 ° C and can withstand very low (-20 ° C) and very high (80 ° C) temperatures. In addition to its good strength, this material provides a polished surface, is reusable and can be welded by chemical processes (using acetone). However, it is not biodegradable and shrinks on contact with the air, which is why the printing platform is heated to prevent parts from peeling off.

We recommend that you use it on a closed-chamber 3D printer to limit particle emissions that may be released during printing.

ABS is used primarily in the melt deposition technique ( FDM ) and, as a result, it is available with most home printers. In addition, a derivative of ABS, in liquid form, is used in the SLA and PolyJet processes .

Plastics in 3D printing PLA

Polylactic acid or PLA, unlike ABS, is biodegradable because it is made from renewable materials (corn starch). One of its main features is its small shrinkage in 3D printing, which is why warming trays are not needed when printing. The printing temperatures should not be very high, between 190 ° C and 230 ° C.

PLA is more difficult to handle because of its high rate of cooling and hardening. It can also be damaged and rub off on contact with water. However, this generally translucent material is used by most FDM 3D printers and comes in a variety of colors.

Plastics in 3D printing ASA

Technically known as Acrylonitrile Styrene Acrylate, this material has properties similar to ABS but with better resistance to UV rays. We can still have some complications during printing, that’s why it is recommended to have a heating plate. The print settings are very similar to those used with ABS – in the case of ASA, be careful to use 3D printers with a closed speaker or to print in an open space because styrene emissions.

Plastics in 3D printing PET

Polyethylene terephthalate, better known as PET, is found mainly in disposable plastic bottles. It is an ideal filament for food-grade, semi-rigid and durable parts. For best printing results, it is necessary to reach temperatures of 75 ° C to 90 ° C. Most often marketed in the form of a translucent filament, there are different variants such as PETG, PETE and PETT. It is a filament that emits no odor during printing and is 100% recyclable.

 

Plastics in 3D printing: PC or Polycarbonate

Polycarbonate (PC) is a very durable material designed for engineering applications. This material is able to withstand high temperatures up to 150 ° C without deforming. Polycarbonate can absorb moisture from the air, which can affect its performance and print resistance. Therefore, it must be kept in airtight containers.

Very high temperatures are necessary for printing: too low a temperature or too much cooling can cause a separation of the printing layers. The polycarbonate filaments that currently exist contain additives that make it possible to print the filament at lower temperatures.

Plastics in 3D printing : Flexible materials

Many types of filaments are now commercially available and one of the most successful is the flexible filaments. They are similar to PLA but made from TPE or TPU. The advantage of these filaments is that they allow to develop deformable objects, widely used in the fashion industry as in the collection of Danit Peleg.

In general, they have the same printing characteristics as PLA and can have different degrees of rigidity. It is recommended to check that the extruder is adequate to prevent the machine from being stuffed.

Plastics in 3D printing: Carbon fibers

Filaments that incorporate carbon fibers are becoming more popular in the 3D industry, especially as 3D printers specialized in this material are developing on the market, such as Markforged . Its success lies in its very high strength, while offering a weight of the final piece lower than those of other materials.

Filaments having these characteristics include small carbon fibers in a base material which can be PLA, PETG, nylon, ABS or polycarbonate, thereby improving the properties of each. The print parameters are usually those of the base material, although it is important to have a suitable machine because the carbon fibers can cause the print nozzle to jam.

Plastics in 3D printing: Hybrid materials

There are different types of materials that mix a base like PLA with a powder that gives them a different color or finish than the one traditionally obtained; these are filaments generally composed of 70% PLA and 30% of the hybrid material. On the market, today we find filaments based on bamboo, cork, wood, etc. The presence of these materials provides a more organic final texture to the filament.

Although there are machines that use the base of FDM technology to extrude metal, such as the new Desktop Metal printers, it is a technology that is not yet available to all. Colorfabb has launched its 3D metal filament . It has the same base as the filaments created with wood but in this case, it is metal powders that are used. This gives 3D printed objects a different color depending on the chosen metal: copper, bronze, silver, etc.

Finally, hybrid materials include filaments that mix rock materials such as cement, brick or sand. They offer a completely different texture for each of the models.

 

Plastics in 3D printing: Soluble materials

Soluble plastics can be used to print print media – depending on the complexity and technology used for the desired part – which will eventually be dissolved. The most commonly used soluble plastics are HIPS (High Impact Polystyrene) and PVA (Polyvinyl Alcohol) which can be dissolved with limonene and water respectively. There are also BVOH filaments or butanediol copolymer and vinyl alcohol, very popular in 3D double extrusion printing to be a water-soluble carrier; according to experts it has better solubility than PVA and is compatible with several materials.

Plastics in 3D printing: SLA

For technologies such as SLA, DLP or even PolyJet , liquid photosensitive resins are used for printing. These can be divided into thermoplastics and thermosolids. Depending on what we choose, they allow printed objects to have a matte or glossy finish. Of these resins, most are plastics mentioned above, but in liquid form.

The range of colors of these technologies is not very varied, one generally finds white, black, transparent, red, although certain recent developments as the new resins Formlabs promise to extend widely this range. What differentiates these materials from those of FDM technologies is that it is not possible to mix resins to achieve different results. Therefore, there are no “double machines”, like double extruders; the only printer we know is the Layer One hybrid machine that combines SLA technology and FDM. The use of resins in 3D printing involves a post-treatment process: it is necessary to clean the parts with isopropyl alcohol for best results.

There are different types of resins that are more technical, among which are the solid resins that are most popular; flexible resins that offer greater deformation of the models; castables which are very used in jewelry making; biocompatibles that focus particularly on the dental sector and the development of dental prostheses.

Plastics in 3D printing : SLS

Selective laser sintering technology uses plastic powders to make parts with a laser that fuses particles layer by layer. There are a variety of different materials that allow artifacts to have different characteristics in terms of strength, flexibility or texture.

Plastics in 3D printing :Polyamides

Polyamide articles are often made from a fine, granular, white powder using Selective Laser Sintering ( SLS ) technology. Some families of this material, such as nylon, are in the form of Filament and are used with the technique of melt deposition ( FDM ).

Thanks to their biocompatibility, like PLA, polyamides can be used for parts in contact with food (except those containing alcohol), and unlike PLA and ABS, smoother surfaces have no effect corrugated are obtained.

Since it consists of semi-crystalline structures, this material offers a good compromise between mechanical and chemical characteristics. Hence its stability, rigidity, flexibility and impact resistance. These advantages give rise to a wide range of applications and a great deal of detail. Superior quality used, for example for the manufacture of gears, parts for aerospace, automotive. Robotics industry, medical prostheses or molds for injection also using this material.

Plastics in 3D printing : Alumide®

Alumide objects are made from a combination of polyamide and powdered aluminum using Selective Laser Sintering ( SLS ) technology. This material  has slightly porous surface and a sandy and granular appearance. Alumide offers high strength, high temperature resistance (up to 172 ºC) and shocks and a relative flexibility. However, post-treatments are usually necessary: ​​grinding, polishing, coating and milling, for example.

Alumide is used for complex models, design parts or for small series of functional models. It superior to the prouct which requiring a high degree of rigidity and an appearance close to aluminum. The technique employed involves weak geometric limits.

Plastics in 3D printing : PP or Polypropylene

Another thermoplastic widely used in our life. Polypropylene in cars, for packaging, disposable professional clothing, and in the manufacture of a hundred objects of everyday life. Polypropylene (PP) is known for its abrasion resistance. This plastic also  has ability to absorb shocks, in addition to a relative rigidity and flexibility.

One of the drawbacks is its low temperature resistance and its sensitivity to UV radiation. That is why several printer manufacturers have developed derivatives of this material. They try to imitate the polypropylenes by  enhance its physical and mechanical properties.

 

, , , , ,

Leave a Reply

Your email address will not be published. Required fields are marked *

*
*