3D Printing

3D Printing

We provide a range of 3d printing services to meet the client's needs and we suggest the best technology that can be cost-effective to fulfill the client needs.

 

Fused filament fabrication

Fused filament fabrication (FFF)

Fused filament fabrication (FFF), also known under the trademarked term fused deposition modeling (FDM), sometimes also called filament freeform fabrication, is a 3D printing process that uses a continuous filament of a thermoplastic material.[1] The filament is fed from a large coil through a moving, heated printer extruder head, and is deposited on the growing work. The print head is moved under computer control to define the printed shape. The file format for printing is .g or .gx. which is created by the 3d printing software. Usually, the head moves in two dimensions to deposit one horizontal plane, or layer, at a time; the work or the print head is then moved vertically by a small amount to begin a new layer. The speed of the extruder head may also be controlled to stop and start deposition and form an interrupted plane without stringing or dribbling between sections.

Process

Fused filament fabrication uses material extrusion to print items, where a feedstock material is pushed through an extruder. In most fused filament fabrication 3D printing machines, the feedstock material comes in the form of a filament wound onto a spool. The 3D printer liquefier is the component predominantly used in this type of printing. Extruders for these printers have a cold end and a hot end. The cold end pulls material from the spool, using gear- or roller-based torque to the material and controlling the feed rate by means of a stepper motor. The cold end pushes feedstock into the hot end. The hot end consists of a heating chamber and a nozzle. The heating chamber hosts the liquefier, which melts the feedstock to transform it into a thin liquid. It allows the molten material to exit from the small nozzle to form a thin, tacky bead of plastic that will adhere to the material it is laid on. The nozzle will usually have a diameter of between 0.3 mm and 1.0 mm.

Materials
ABS
PLA
PETG
Nylon
Wood composite PLA
Fluorescent PLA
Carbon composite PLA

Advantages
Low Cost
Good Strength

Disadvantages
Supports need to be removed carefully
Post processing is required for better finish

Criteria for choosing FFF
The product is in the R&D stage
Multiple prototypes are required
The product does not have sharp details
Strength is required for functional testing
Surface roughness is not an issue

Stereolithography(SLA)/DLP

Stereolithography (SLA)

The Stereolithography (SLA) process is based on light-curing photopolymerization of liquid materials into a solid shape.

Process

a) light-emitting device (a laser or DLP)
b) Tank filled with resin
c) Transparent bottom
d) Solidified resin
e) Lifting platform

In this process, a vat of liquid polymer is exposed to controlled lighting (like a laser or a digital light projector) under safelight conditions. Most commonly the exposed liquid polymer hardens through cross-linking driven by the addition reaction of carbon-carbon double bonds in acrylates.[30] Polymerization occurs when photopolymers are exposed to light when photopolymers contain chromophores, otherwise, the addition of photosensitive molecules is utilized to react with the solution to begin polymerization. The polymerization of monomers leads to cross-linking, which creates a polymer. Through these covalent bonds, the property of the solution is changed.[31] The build plate then moves down in small increments and the liquid polymer is again exposed to light. The process repeats until the model has been built. The liquid polymer is then drained from the vat, leaving the solid model.

SLA process uses a point laser beam white DLP uses a layer of projector-based light that projects on the entire layer at a single instant and this process is prone to pixel density accuracies and is only as accurate as of the projector resolution.

SLA process uses a beam that cures an area equal to the diameter of the point and has better accuracy than DLP.

Materials
Castable resin
ABS resin
High-Temperature resin

Advantages
As printed surface finish is very good similar to a regular production part.
Very little post-processing is required where supports are present.

Disadvantages
High cost resins need to be used for good strength
Even low cost resins are expensive than FFF materials
Continuous exposure to ambient or UV light will make the parts brittle and break.

Criteria for choosing SLA
The product is in final prototype stages
The prototype is required for product display or presentation
Cost is not an issue

Selective laser sintering (SLS)

Selective laser sintering (SLS) is an additive manufacturing (AM) technique that uses a laser as the power source to sinter powdered material (typically nylon or polyamide), aiming the laser automatically at points in space defined by a 3D model, binding the material together to create a solid structure.
An additive manufacturing layer technology, SLS involves the use of a high power laser (for example, a carbon dioxide laser) to fuse small particles of plastic, metal, ceramic, or glass powders into a mass that has a desired three-dimensional shape. The laser selectively fuses powdered material by scanning cross-sections generated from a 3-D CAD file or scan data on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness, a new layer of material is applied on top,and the process is repeated until the part is completed.[5]

Selective laser sintering process
1. Laser                                                             A. Laser scanning direction
2.Scanner system                                             B.Sintered powder particles (brown state)
3. Powder delivery system                               C. Laser beam
4. Powder delivery piston                                D. Laser sintering
5. Roller                                                           E. Pre-placed powder bed (green state)
6. Fabrication piston                                        F.Unsintered material in previous layers
7. Fabrication powder bed
8.Object being fabricated (see inset)

Because finished part density depends on peak laser power, rather than laser duration, a SLS machine typically uses a pulsed laser. The SLS machine preheats the bulk powder material in the powder bed somewhat below its melting point, to make it easier for the laser to raise the temperature of the selected regions the rest of the way to the melting point.[6]
In contrast with some other additive manufacturing processes, such as stereolithography (SLA) and fused deposition modeling (FDM), which most often require special support structures to fabricate overhanging designs, SLS does not need a separate feeder for support material because the part being constructed is surrounded by unsintered powder at all times, this allows for the construction of previously impossible geometries. One design aspect which should be observed however is that with SLS it is 'impossible' to fabricate a hollow but fully enclosed element. This is because the unsintered powder within the element could not be drained.

Materials
Polyamides
Polystyrenes
Thermoplastic Elastomers
Polyaryletherketones

Advantages
Supports are not generated.
Good strength and flexibility

Disadvantages
Grainy surface texture
Expensive than FFF technology

Criteria for choosing SLS
Some amount of flexibility is required in the product
The parts should not have support marks
Small roughness is not an issue
The product has a living hinge