The most common filament for 3D printing is PLA (polylactic acid), a biodegradable thermoplastic derived from renewable resources such as corn starch or sugar cane. PLA is widely used for 3D printing because of its low cost, ease of use, and environmental friendliness. However, PLA also has some limitations, such as low heat resistance, brittleness, and poor adhesion to some surfaces. In this article, we will explore the properties, advantages, and disadvantages of PLA, as well as some alternatives that may suit different applications and preferences.
PLA is a type of thermoplastic, which means it can be melted and reshaped by applying heat. PLA has a relatively low melting point of around 180°C to 220°C, which makes it compatible with most 3D printers. PLA also has a low shrinkage rate, which reduces the risk of warping or cracking during printing. PLA is available in a variety of colors and finishes, such as glossy, matte, transparent, or metallic. PLA can also be blended with other materials, such as wood, metal, or carbon fiber, to create composite filaments with enhanced properties.
Some of the physical and mechanical properties of PLA are:
Density: 1.24 g/cm3
Tensile strength: 37 MPa
Tensile modulus: 2.7 GPa
Elongation at break: 6%
Flexural strength: 60 MPa
Flexural modulus: 3.5 GPa
Impact strength: 5 kJ/m2
Glass transition temperature: 60°C
Advantages of PLA
PLA has many advantages that make it a popular choice for 3D printing, especially for beginners and hobbyists. Some of the benefits of PLA are:
Low cost: PLA is one of the cheapest filaments on the market, making it affordable for anyone who wants to try 3D printing.
Ease of use: PLA is easy to print with, as it does not require a heated bed, a closed chamber, or a cooling fan. PLA also has good flow and adhesion, which reduces the chances of clogging, stringing, or curling.
Environmental friendliness: PLA is biodegradable and compostable, which means it can be disposed of in an eco-friendly way. PLA is also made from renewable resources, which reduces the dependence on fossil fuels and the emission of greenhouse gases.
Quality and accuracy: PLA can produce high-quality prints with fine details and smooth surfaces. PLA also has a high dimensional accuracy, which means it can reproduce the exact shape and size of the digital model.
Despite its many advantages, PLA also has some drawbacks that may limit its applications or require some modifications. Some of the disadvantages of PLA are:
Low heat resistance: PLA has a low glass transition temperature of 60°C, which means it can deform or melt when exposed to high temperatures. This makes PLA unsuitable for printing objects that will be used in hot environments, such as engine parts, cookware, or outdoor items.
Brittleness: PLA is prone to cracking or breaking under stress or impact, especially after prolonged exposure to moisture or UV light. This makes PLA less durable and flexible than some other filaments, such as ABS or PETG.
Poor adhesion: PLA does not stick well to some surfaces, such as metal, glass, or acrylic. This may cause the print to detach from the bed or the layers to separate during printing. To improve the adhesion of PLA, some methods can be used, such as applying glue, tape, or hairspray to the bed, or using a heated bed with a temperature of 50°C to 70°C.
Alternatives to PLA
Depending on the desired characteristics and applications of the print, some alternatives to PLA may be more suitable or preferable. Some of the common alternatives to PLA are:
ABS (acrylonitrile butadiene styrene): ABS is a strong and durable thermoplastic that can withstand high temperatures and impacts. ABS is ideal for printing functional parts, such as gears, brackets, or cases. However, ABS is also more difficult to print with, as it requires a heated bed, a closed chamber, and a cooling fan. ABS also emits a strong and unpleasant odor during printing, which may be harmful to health and the environment.
PETG (polyethylene terephthalate glycol): PETG is a modified version of PET, the plastic used for water bottles. PETG combines the strength and durability of PET with the flexibility and ease of use of PLA. PETG is resistant to heat, water, and chemicals, and has a high impact strength and transparency. PETG is suitable for printing objects that require both strength and flexibility, such as containers, bottles, or hinges. PETG is also easy to print with, as it does not require a heated bed or a closed chamber, and has a low odor and a high adhesion.
TPU (thermoplastic polyurethane): TPU is a flexible and elastic thermoplastic that can bend and stretch without breaking. TPU is ideal for printing objects that require a high degree of flexibility, such as phone cases, belts, or shoes. TPU is also resistant to abrasion, oil, and grease, and has a smooth and glossy finish. TPU is relatively easy to print with, as it does not require a heated bed or a closed chamber, and has a low shrinkage and a high adhesion. However, TPU is also more expensive and slower to print than PLA, and may require a direct drive extruder and a lower printing speed.
PLA is the most common filament for 3D printing because of its low cost, ease of use, and environmental friendliness. PLA can produce high-quality prints with fine details and smooth surfaces, and can be used for a variety of applications, such as prototyping, modeling, or art. However, PLA also has some limitations, such as low heat resistance, brittleness, and poor adhesion to some surfaces, which may require some modifications or alternatives. Depending on the desired characteristics and applications of the print, some alternatives to PLA may be more suitable or preferable, such as ABS, PETG, or TPU. By choosing the right filament for the right project, 3D printing can be a fun and rewarding experience.
