Compared with open mold, in-house manufacturing can greatly reduce costs and allow for more freedom for rapid prototyping. The three 3D printing technologies currently in use in the market are FFF (fuse manufacturing), SLA (light-curing), and SLS (laser powder sintering).
The principle common to all 3D printing technologies – the 3D CAD model is cut horizontally into individual cross sections, and then stacked to form three-dimensional; But FFF, SLA, and SLS technologies take fundamentally different approaches.
1. FFF (Fuse manufacturing)
Advantage
. Easy to operate and maintain
. More affordable and cost-effective than other major 3D printing methods
. Relatively clean, no harsh chemicals required
. The device size can be placed on the desktop
. The whole process takes place inside the machine – no additional equipment is required
. A variety of materials are available and also have engineering characteristics
. The relatively low equipment price helps shorten the product delivery time
Shortcoming
. The surface usually has a stacked grain
. The lamination quality affects the physical strength of the finished product
SLA uses UV-cured resin as raw material, pours it into the resin tank, and immerses it into the printing platform; Use UV laser or DLP projector to shine UV light on the resin. The printing area of each horizontal section is hardened and stacked by a platform raised from the container to smooth the uncured resin until printing is complete.
SLA is suitable for complex parts that require precise detail, but in almost all cases, printed parts require support structures. Post-treatment is more complex than FFF: harsh chemicals such as isopropyl alcohol are used for cleaning, and curing in a UV oven is required for processing. Due to the use of harsh chemicals, post-treatment in a well-ventilated area is required. Resin raw materials have a pungent taste, flammable, and have a short shelf life, new and old resins can not be mixed, so waste materials will lead to increased costs, and the price of materials is higher than other technologies.
Advantage
. Suitable for parts with complex shapes
. The finished surface is smooth with few stacked lines
. It can present the best detail and is ideal for small parts
. The equipment is integrated and relatively easy to operate
. Materials with multiple properties can be printed
Shortcoming
. Raw materials are often chemically irritating or pungent and flammable
. The reagent is added during post-treatment
. The material is sticky and may be buried in the environment
. Support structures are usually required and may leave marks on the surface
. It is not yet possible to use multiple materials or colors simultaneously in a single print
. The printable volume is relatively small compared to the other two technologies
. Hollow parts must be prepared with holes for uncured resin to flow out
3. SLS (Laser Powder Sintering)
The raw material is powder polymer, the powder is stored in a container, and the thin layer of powder is placed in the printing range inside the machine; Then a single horizontal layer is built with laser light fusion material, and then the printing product is repeatedly stacked with a slight height rise and fall; Unused powder can be sifted through special equipment and then mixed with new powder.
It is suitable for works with complex design, a large degree of freedom, and no support, and the finished surface does not produce a laminated texture; SLS is the more expensive of the three 3D printing technologies in terms of initial setup and maintenance, and the complexity of the equipment also requires skilled operators. Maximum volume is recommended for printing to avoid wasting powder. Due to the use of high-power laser light and powder raw materials, SLS needs to consider more environmental safety.
Advantage
. The finished product has a light powder and no laminated texture
. The parts have high mechanical properties
. No support material is required for printing
Shortcomings
. Relatively large equipment
. The finished product must wear a mask to prevent dust inhalation
. Less variety or color of material
. Equipment and materials are relatively expensive, and operation and maintenance require initial learning
. The powder needs to be processed and recovered after treatment
. It is more cost-effective when the print volume fits the entire container range
Comparative induction
Each of the three technologies has its strengths, and there is no so-called good or bad, But FFF technology is the most common because it’s affordable and doesn’t require extra space or expertise. So that the average small and medium-sized enterprises can also shorten the development time and cost, products can be directly in the company for rapid prototyping, while requiring minimal post-processing and waste disposal. In addition, because most people use it, the most information is available. SLA is ideal for printing small objects with complex details, action figures, modeling objects, etc. SLS is ideal for mechanical, functional, and large-scale industrial prototypes.
