FDM 3D printing and additive technology

FDM 3D printing and additive technology

Additive synthesis technology or layering technology is the fastest growing trend of "digital" production today. There are many technologies that can be called additive, because the one thing unites them: the construction of the model is done by adding material (from English ''ADD''), unlike traditional technologies, where the creation of parts is done by removing "unnecessary" material.

As soon as production becomes digital, there is an interesting trend: it becomes profitable to produce items in small quantities, with more flexibility and lower labor share thanks to new materials, technologies (such as 3D-printing) and Internet services. That is intensively developing a so-called additive manufacturing - the ability to create the final functional product, in a single copy or small-scale circulation, using a wide range of materials, but without using special technology cycles and, therefore, reducing the time and cost.

The beginning of mass use of 3D-printing is called the third industrial revolution. First revolution launched in UK at the end of the XVIII century in the form of mass mechanization of textile production. Using the machine then quickly spread throughout the world. The second industrial revolution occurred with the advent of the conveyor line - so began the era of mass production at the beginning of the XX century.

Now 3D-printing heavily integrates into all spheres of human activity. Printed machine, printed plane, printed bicycle, printed kidney - this is not the whole list of achievements of modern science. But the most interesting thing is that you can print with using almost everything: metal, plastic, wood and ... even food.

Today, there are many technologies to create real objects from 3D models. They are actively developing. The most actual- printing with plastic due to accessibility and usability.

All 3D-printing technology is based on four basic methods for processing of polymers: Extrusion - extrusion of molten material, Light cured - the hardening of polymer UV or laser radiation, Granulation - bonding or sintering material particles and Laminating - gluing layers of material and then cutting.

Technology of 3D-printing

Thermoplastic power Production of models for casting

A method of building layers

3D-printing technologyTypes of polymers usedApplication area
Extrusion
FDM (Fused Deposition Modeling) - modeling with fusingThermoplastics (ABS, PET, PC, PA, etс.), low-melting metals and alloysCreating a three-dimensional models, prototyping, using in industrial production
DOD Jet (Drop-On-Demand-Jet) - spraying droplets of the heated materialCast waxJewelcrafting, the creation of implants, rapid prototyping
SFF (Solid Freeform Fabrication)Chocolate, hydrocolloidsFood industry
Photopolymerization
SLA (Stereolithography) Photopolymer resinThe molds for injection molding, thermoforming, blow molding
DLP (Digital Light Processing) light digital treatmentLiquid resin
MJM (Multi Jet Modeling)Photopolymer resin, acrylic plastic, wax castingManufacture of electronic components and connectors, demonstration models, handles, knobs, medical equipment and complex geometry parts.
PolyJetPhotopolymer resin
Lamination

LOM (Laminated object manufacturing) - layer-bonding thin films and the subsequent cutting of the object contoursPaper, metal foil, plastic filmProduction of large and bulky components for the aerospace and automobile industries
Granulation

DMLS (Direct metal laser sintering)

Any metal alloy in the form of pellets, crumbs, powderProduction of pieces with complex geometries and structures with thin walls, as well as cavities or channels. The cosmic construction. Production of medical implants

SLM - selective laser melting (analogue DSLM)

Like powders: stainless steel, tool steel, chromium, titanium, cobalt, aluminum
EBM (Electron Beam Melting) Titanium alloys
SHS (Selective heat sintering)
SLS (Selective laser sintering) Thermoplastics, metal powder, ceramic powder
3DP — powder bondingGypsum, gypsum-based composite, plaster powderDetails with irresponsible destination
Full Color Printing — Color 3D PrintingGypsum


FDM 3D printing - the most common and available technology - layering of the polymer melt.

The main structural element of FDM-3D-printer is the print head, which consists of an extruder and a heater. The extruder - a mechanism, that metered polymer thread in the heater. Heater - is the part of the print head, in which the polymer is melted and extruded filament through a tiny nozzle with diameter of 0.15-0.50 mm. The heater nozzle is often called the hot-end, a similar extruder - is cold-end.

Stepper motor with gears and shafts system is used for supplying polymer filaments in the printhead. A controller of the motor provides the necessary feed rate of the filaments and in case of their withdrawal -change the material. Printhead temperature is controlled by heater thermistor.

The most important aspect - the size of the extruder nozzle. Mostly, printing quality depends precisely on it. Manufacturers of 3D-printers are usually equipped their extruder nozzle with a hole diameter of 0.4-0.5 mm - this size is optimal. In turn, the use of smaller diameter of a nozzle (0.3-0.2 mm) can provide better granularity, sharpness and clarity of the object surface, as the smaller droplets are extruded plastic.

Currently, on the market there are several models of 3D-printers, the heads of which are equipped with two (or even three) extruders. Double-extruder is well suited for printing two-colored objects or creating support structures of soluble polymer. But, in general, double extrusion technology is still under development, so it has many disadvantages, in particular, modern 3D-printers can not be printed fully with both extruders simultaneously - they are rigidly secured on a common printhead, and do not move independently. Therefore, printer uses each extruder as need.

Furthermore there are atypical extruders, for example, non-commercial version of this printhead. They are capable to mix several kinds of polymer yarns. In fact, these are three separate extruders with a common nozzle.

Various polymeric materials in the form of monofilaments 1,75mm in diameter, and 3.00 mm are used to make products using FDM 3D-printing. The most common - is ABS plastic, HIPS - high-impact polystyrene, PLA - PLA, PET, PC, HDPE. In addition, it is possible to develop special materials for FDM 3D-printing, which will have the desired characteristics, such as increased flexibility, reduced flammability, electrical conductivity.

FDM 3D printing technology allows you to receive a variety of items - gifts, toys, machine parts and tools, containers and packaging. Three-dimensional printers can produce trial packaging mock-ups, vials and bottles of the original form. Prototypes can be colored, with the inclusion of all the design elements, such as labels, bar codes, logos. Ready-Packaging can be demonstrated to the customer before starting mass production. The advantage of 3D prototypes is that customers can hold the package in hand, to evaluate its texture, color scheme and some other characteristics.

3D-printing technology is actively gaining popularity and are constantly evolving and improving. Although there are now a number of shortcomings in the three-dimensional printing technology - low speed, limited in size - but progress does not stand still.

Posted: July 7, 2016
Was this article helpful? Yes No

0 comments

    Add comment

    To add a comment please sign up or login
    Real Time Web Analytics