At present, the most popular 3D printing technologies in the market include melt deposition molding technology and light-curing molding technology. And a FDM 3D printer is sually considered to be the best 3d printer for beginners. Why? Because 3D printing with FDM technology has many advantages, such as low cost, a wide range of printing materials to choose, less environmental pollution, small size equipment, high utilization of raw materials, relatively simple post-treatment, etc. In today’s article, we will explain the 3d printing basics and offer some guide for 3d printing beginners.
What is Melt deposition molding?
Melt deposition molding uses fusible thermoplastic materials as filament. The filament is heated and melted in the nozzle.
The printer nozzle moves along the profile of the model/product under the control of the computer, and the melted material is extruded at the same time to form a new layer. The material is solidified quickly after extrusion, bonded with the previous layers/last payers, through layer after layer of stacking molding, and finally form/print a complete model/product.
While light-curing requires special materials, which are cured by laser heating technology. Today let’s discuss the pros and cons of FDM printing technology.
Fused deposition molding (FDM) is the most widely used 3D printing technology at present. Fused deposition 3D printers are higher in sales and popularity than light-cured 3D printers. The materials it uses are usually low melting point plastics, such as ABS/PLA. The printing materials are first made into filaments (small lines), fed into the nozzle through a material feeding mechanism. Fusible thermoplastic materials are heated and extruded from the nozzle and then stacked layer by layer to form a complete product.
The application fields of FDM include conceptual modeling, functional prototyping, manufacturing, and processing, involving automotive, medical, architectural, toys, electronics, and other areas. With the progress of technology, the application of FDM is still expanding.
What 3D printing materials/filaments do an FDM 3D printer use?
For 3D printing, printing material is essential. The materials involved in the FDM technology mainly include molding materials and supporting materials. Molding materials are used to form a product. While supporting material will be removed after printing. According to the technical characteristics, molding materials usually have a low melting temperature, low viscosity, good adhesion, low shrinkage, etc. Support materials are required to not infiltrate with the molding materials, have water solubility or acid solubility, have a low melting temperature, good fluidity, etc. The molding materials are mainly thermoplastic, including ABS, PLA, TPU, PETG, PE, PC, synthetic rubber materials, and supporting materials are usually HIPS and PVA.
ABS, an acrylonitrile-butadiene-styrene copolymer, is one of the five major synthetic resins. It has excellent impact resistance, heat resistance, low-temperature resistance, chemical resistance, and electrical properties. It also has the characteristics of easy processing, stable product size, easy painting, and coloring. It can also carry out secondary processing such as surface spraying metal, electroplating, welding, hot pressing, and bonding. It is widely used in machinery, automotive, electronic and electrical appliances, instruments, textile and construction, and other industrial fields. ABS filament is a prevalent printing material in 3d printing.
PLA, namely polylactic acid, has good thermal stability and good solvent resistance and can be processed in various ways, such as extrusion, spinning, biaxial stretching, injection blow molding.
The products made from polylactic acid are biodegradable. They also have good biocompatibility, glossiness, transparency, and heat resistance, and UV resistance. Products printed by PLA are widely used in packaging materials, household decoration display products, toys, medical and health, and other fields. It is quite a good idea to print vases and other home decoration products with 3D printing and through 3D printing.
TPU (Thermoplastic Urethane) is a mature environmental protection material between rubber and plastic. Its products have good flexibility, elasticity, and wear resistance. In addition, they can be bent and deformed, so they are widely used in shoe manufacturing, medical and health, electronic and electrical appliances, industry, and sports. Products printed by TPU have some softness, some 3D printer users use TPU to print shoes.
PETG is called polyethylene glycol terephthalate. It is a bio-based plastic synthesized from bio-ethylene glycol produced by sugarcane ethylene. PETG has outstanding thermoformability, toughness and weather resistance, high printing success rate, and has the advantages of both PLA and ABS. First of all, PETG has low shrinkage and it is not easy to warp; at the same time, it has the same high toughness as ABS, which is not easy to break under high pressure; food-grade, odorless; and has good hydrophobicity, not easy to be damp, and does not need to be stored in an airtight space. The 3D printed products have a high gloss, smooth surface, and translucent effect. In terms of price, it is generally a little more expensive than PLA and ABS. It is widely used in medicine, such as orthopedics and prosthetics.
Support material: PVA and HIPS for dual nozzle 3D printer
As the name implies, it plays a supporting role in the forming material in the 3D printing process. After the 3D printing, the support material needs to be removed/stripped, so it must also have certain properties. At present, the support material is generally water-soluble; it can be dissolved in water and is easy to peel off.
For a single nozzle 3D printer, the support material is the same as the printed model. After the product is printed, you need to remove the support material.
But the dual-head/dual nozzle 3D printer can use two different printing materials, one for printing the model itself and the other for printing supports. Print the support parts with water-soluble material, making it easy to remove the support without causing any damages to the model.
Currently, two types of soluble carrier materials are commonly used in 3D printing: PVA (polyvinyl alcohol) and HIPS (High impact resistance polystyrene).
The PVA is water-soluble and can be used in 3D printing process as a supporting structure. This material is not only soluble in water but also easy to remove. If the water temperature rises slightly, it will dissolve more quickly. However, a special problem needs to be paid attention to when using PVA in 3D printing: PVA materials must be stored appropriately and sealed and should not be placed in high-temperature places. Why? Because the PVA material quickly absorbs moisture in the air, and becoming very thick is not conducive to 3D printing. At the same time, PVA material is sensitive to temperature. If the temperature is too high, it is easy to clog the nozzle.
HIPS material, which is also soluble. But it is insoluble in water and can only be dissolved in limonene. It tastes good. When the model/product is printed, put the model/product into the limonene, and the HIPS material (support parts) will dissolve automatically.
Generally speaking, different 3D printing materials and 3D printing filaments have different characteristics and advantages. We need to choose the appropriate printing material according to our own printing needs.
Advantages of FDM technology:
1). Low cost. The cost of equipment is low, the utilization efficiency of raw materials is high and chemical pollution so that the cost is greatly reduced.
2). The use of water-soluble support materials makes it simple and easy to remove the support structure and can quickly build complex inner cavities, hollow parts, and once-molded assembly structures.
3). Raw materials are provided in coiled materials, easy to handle and easy to replace.
4), can use various printing materials, such as multiple colors of engineering plastics ABS, PC, PPS, medical ABS, etc.
5). The raw materials have no chemical change in the forming process, and the warping deformation of the parts is small.
6). The prototype parts molded with wax can be directly used in investment casting.
7). no need to spend money to establish a special site for FDM printing. It is suitable for use in the office design environment.
Compared with other 3D printing technologies, FDM technology does not involve dangerous links such as laser, high temperature, and high pressure. It is a relatively low-cost 3D printing technology that can widely use in home and office environments.
Disadvantages of FDM technology:
1). The prototype’s surface has obvious stripes/layers, the forming precision is relatively low, and the highest precision is 0.127mm.
2). we need to do the modeling and add some support parts to the model before 3D printing.
3). Printing takes a long time, and the forming speed is about 7% lower than that of SLA.
4). The nozzle may be clogged and needs to be maintained or replaced.
In this article, we talk about some 3d printing basics knowledge and introduce to you some different 3d printing filaments. We sincerely hope that with this 3d printing beginners guide, you can choose the suitable printing filament to meet your printing demands. For most people, their first 3D printer is an FDM 3D printer. If you are a new to a 3D printer, and plan to buy a 3D printer to design your own model and print some unique produc ts for fun in your spare time, then the FDM 3D printer is a good choice for you.