The Origins of 3D Printing

The initial contact might feel a bit confusing, but you must know that adding bricks layer by layer to build a building is quite similar to the principle behind 3D printing.

The origin of 3D printing can be traced back to the 1980s. In 1983, American engineer Charles Hull invented “stereolithography” (SLA), which is considered the first 3D printing technology. He used ultraviolet light to cure liquid photopolymer resin, solidifying it layer by layer to create a three-dimensional object. This is why he’s often referred to as the “father of 3D printing.”

The Working Principle of 3D Printing

3D printing, also known as additive manufacturing, is the opposite of subtractive manufacturing techniques like CNC machining. Its working principle involves breaking down a complex three-dimensional structure into countless two-dimensional planes, building it up layer by layer to turn a virtual model into a physical object. This overcomes the limitations of traditional subtractive methods (such as cutting) in terms of geometric shapes.

Stereolithography technology was initially used for rapid prototyping, and its key advantage lies in its ability to efficiently create physical prototypes of new parts and products.

Why is 3D printing so popular?

Compared to traditional manufacturing methods, 3D printing has several advantages:
It can create complex geometries at the lowest cost and quickly validate designs.
It can integrate multiple components that would normally require assembly into a single part.
It eliminates the need for upfront mold costs, enabling parts validation early in the process.
It accelerates production, allowing for fast access to parts.
The biggest advantage of 3D printing is its rapid iteration capability. You can get a “draft” part every day, identify design flaws, and make adjustments. This provides designers and engineers with a more convenient way to verify their solutions.

How Does 3D Printing Work?

SLA 3D printing machine producing high-precision resin parts with smooth surface finish
Like manufacturing other parts, the first step in 3D printing is for the designer to create a three-dimensional model in CAD software. Then, this digital file can be sent to the printer, which starts building the physical object layer by layer.Different printing methods vary slightly: some begin with powder or liquid resin, while others extrude material layer by layer like an inkjet printer. Then, through chemical reactions, ultraviolet light exposure, or high-powered lasers, the material is solidified or fused layer by layer to ultimately form the complete part.
Of course, the 3D printing process goes beyond just these methods. In the following chapters, we will provide a detailed introduction to various different techniques.

What Are The Common 3D Printing Technologies?

 SLA (Stereolithography):

3D Printed SLA (Stereolithography) Part

SLA is a 3D printing technology based on photopolymer resin curing. The principle involves using a UV laser to scan and cure the resin point by point in a liquid resin vat, forming a thin layer. After each layer is cured, the build platform lowers by one layer thickness, allowing fresh resin to cover the cured layer. The process repeats, curing the resin layer by layer to ultimately form a three-dimensional part. After the formation is complete, excess resin must be cleaned off, and secondary UV curing is performed to enhance the mechanical properties and stability of the part.

Advantages of SLA:

High precision, with errors controllable within ±0.1mm. Smooth and delicate surface finish, with high detail reproduction. A wide variety of photopolymer resins available to meet different needs,Relatively fast printing speed (especially for small-sized parts) and low cost.

Disadvantages of SLA:

Long-term stability is insufficient; parts exposed to sunlight or UV light for extended periods may experience aging, yellowing, and performance degradation. Low strength, limiting its suitability for functional testing.

Applications:

Strict tolerance requirements.Smooth, fine surface finish.Small parts with high detail reproduction.

SLS (Selective Laser Sintering)

3D Printed SLS (Selective Laser Sintering) Part

Infrared lasers or CO2 lasers are used to scan and sinter the powder bed layer by layer: First, the metal powder is uniformly heated to a temperature slightly below its melting point using a preheating system. Then, the laser beam scans according to the cross-sectional data of the 3D CAD model, causing the powder particles to fuse and form under the thermal influence. Un-sintered powder particles naturally form a support structure, preventing collapse in areas with overhangs. After sintering one layer, the build platform moves down 0.1-0.3mm along the Z-axis, and the powder spreading device evenly lays down a new layer of powder. This process is repeated until the entire part is formed.

Advantages of SLS:

Excellent mechanical properties.

Products are sturdy and durable.

Excellent corrosion resistance.

Disadvantages of SLS:

Printed parts may have a noticeable grainy texture on the surface.

Dimensional accuracy is lower than SLA.

Large parts may experience deformation issues.

Applications:

Used to verify the mechanical performance and assembly feasibility of parts.Can be used to manufacture lightweight, high-strength complex parts.

FDM (Fused Deposition Modeling)

3D Printing FDM (Fused Deposition Modeling) Process

The filament material (wire) is fed into the nozzle through a feeding mechanism. An integrated heating device inside the nozzle melts the filament into a semi-liquid state. The nozzle moves along the sliced path on the print bed, extruding the molten material and depositing it in the specified locations. The material quickly cools and solidifies to form one layer of structure. After each layer is completed, the platform lowers (or the nozzle rises) by the thickness of one layer, and the extrusion and curing process is repeated until the part is fully formed.

Advantages of FDM:

Low equipment and material costs.
A wide variety of materials available, with high safety.
Offers a certain level of strength.

Disadvantages of FDM:

Lower precision, with noticeable layer lines and rough surface finish.
Limited suitability for functional testing.
Low strength in the Z-axis direction.

Applicable Scenarios for FDM:

Rapid prototyping to verify structure and assembly relationships.Suitable for functional parts that require chemical resistance or high-temperature resistance.

SLM(Selective Laser Melting)

3D Printed SLM (Selective Laser Melting) Metal Part
A high-power laser beam (typically fiber laser) is used to completely melt and solidify the metal powder, layer by layer, forming a dense metal part. The forming process must be carried out in an inert gas environment to prevent metal oxidation.

Advantages of SLM:

High part density, approaching or even equivalent to forged material performance. Capable of producing parts with complex geometries.

Disadvantages of SLM:

Low efficiency, not suitable for mass production.

High cost.

Rough surface finish, usually requiring post-processing or surface treatment.

Applicable Scenarios for SLM:

Suitable for parts with complex structural shapes.

Suitable for high-strength, high-hardness, wear-resistant, and high-temperature functional metal parts.

One-piece formation reduces the need for metal components in assemblies.

MJF (Multi Jet Fusion)

3D Printed MJF (Multi Jet Fusion) Part

The principle of MJF (Multi Jet Fusion) technology involves first laying a layer of polymer powder on the build platform. Then, a selective application of fusing agent and detailing agent is sprayed. Infrared light is used to rapidly melt and solidify the areas sprayed with the fusing agent, while the detailing agent controls the precision of the surrounding areas. After each layer is completed, the platform lowers by one layer thickness, and the process is repeated layer by layer until the complete 3D part is formed.

Advantages of MJF:

Suitable for manufacturing strong, durable, and heat-resistant functional parts.

Uniform mechanical properties across parts.

Cost-effective.

Disadvantages of MJF:

Very large parts are difficult to print directly.

Potential risk of deformation.

Applicable Scenarios for MJF:

Parts requiring high strength and toughness.

Functional verification parts and prototypes.
Complex parts with fine details and intricate structures.

What are the defects of 3D printing and methods to avoid them?

When 3D printing parts, DFM (Design for Manufacturability) guidelines should be followed to avoid the following issues: Following DFM principles is key to avoiding problems with 3D printed parts. The following points should be considered during the design process:

Be cautious of warping and deformation issues

Deformation of 3D printed parts can be caused by various factors, such as material properties, printing environment, and part design. Effective methods to prevent warping include optimizing the print orientation, reducing overhangs, adding support structures, increasing wall thickness, and incorporating reinforcement ribs in large surface areas to prevent sagging.

Avoid large overhang structures

In 3D printing, large overhang structures can cause issues because they require support structures underneath. This not only increases print time and material consumption but can also lead to a decrease in surface quality at the bottom of the overhang.

Avoid thin-walled structures

Thin walls are prone to deformation or breakage due to insufficient strength and may also cause warping or delamination during the printing process. Extremely thin wall thicknesses can lead to poor layer adhesion, rough surfaces, and may even prevent successful printing.

Post-Processing for 3D Printing

Do you need to enhance the strength or appearance of your 3D-printed parts? We offer a variety of post-processing options, including anodizing, secondary machining, and custom surface treatments such as painting and decaling.
Surface Finish Options
NaturalAchieve a clean look with supported surfaces professionally sanded to remove any visible support marks.
StandardGet a smooth, uniform appearance with sanded support areas and fine media blasting across the entire part, while subtle layer lines remain for an authentic 3D-printed look.
CustomElevate your parts with premium finishing options, including soft-touch coatings, high-clarity finishing, professional painting, masking, precise color matching, decals/graphics, and textured surfaces tailored to your needs.
Clear CoatClear cosmetic finish that can be applied to ABS-Like Translucent/Clear and PC-Like Translucent/Clear materials.
PaintingAfter smoothing the part with sanding and polishing,parts can be painted with automotive-grade paint. Provide a pantone color with your quote request.We also offer soft-touch painting.
DyeingDyeing is another method for adding color to 3D prints. This is faster option with alimited color selection, so is a more cost-effective choice than painting.
DecalingDecaling can be used to add a logo or other graphics to boost cosmetics or function.
PolishingWe can polish parts to a miror-like finish.If this is a requirement,we ask that you provide either a drawing or image that indicates your finish expectations.
Heat TreatmentHarden and strengthen metal 3Dprints with multiple heat treatment options: NADCAP heat treatment, hot isostatic pressing (HIP), solution annealing,and aging.
MachiningMachine metal 3D prints to achieve exceptional surface finish quality or meet tight tolerances.

Whether you’re creating prototypes or producing end-use parts, additive manufacturing (3D printing) offers significant advantages. We provide a wide range of materials and processes, enabling ultimate geometric flexibility and rapid iteration, so you can receive high-quality parts in just a few days. For any questions about quotes or design, our applications engineers are ready to provide expert guidance and support to ensure your project runs smoothly. We look forward to collaborating with you on your next project!

What file formats are supported for 3D printing CAD files?

Regardless of which software you use for design, please ensure that the submitted CAD files comply with the following format requirements.
File formats (.stl, .stp/.step, .sldprt, .igs/.iges)

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