ABS VS PLA? What filament should I use in 3D printing

One of the questions that beginners of 3D printing enthusiasts often ask is: which material is better? ABS or PLA? How can I choose the suitable printing material/filament for my printing?

Generally speaking, ABS and PLA belong to the materials used in FDM technology, and they are also the two most commonly used consumables in 3D printing. Among them, PLA is the first choice for most people. PLA is cheap, has various colors to choose from, is easy to print, and the finished product is solid and beautiful, which sounds perfect. But in that case, why do we need ABS? ABS has its advantages as well. It does outperform PLA in some aspects, mainly in terms of durability and high hardness. Therefore, ABS is more suitable for printing some products that require high wear performance.

Here are the main differences between ABS filament and PLA filament:

1. The raw materials of these two filaments are different.

PLA (polylactic acid) is a biopolymer. It’s biodegradable plastic. It is made of renewable materials, such as corn starch, cassava, sugarcane, etc.. With good biodegradability, it can be recycled, and decay will disappear. It is recognized as a kind of environment-friendly bioplastics. It is more eco-friendly than ABS. After all, it is made from plants. This material also has a pleasant smell.

ABS is the abbreviation of acrylonitrile-butadiene-styrene. It is a thermoplastic engineering plastic with high strength and impact resistance, which can not be biodegraded but can be recycled.

2. Different physical properties/softness.

The surface of the product printed by PLA is brighter than that of ABS. Its surface hardness is high, but it is easier to break when bending. PLA material is a little more fragile than ABS, and the products printed by PLA are easy to crack or break in a collision. We can cut, file, polish, paint and glue PLA printed products.

ABS is naturally matte and is not glossy on its surface. ABS products can withstand more pressure. It will bend under pressure but generally will not break. It has better plasticity, and we can use acetone to improve the smoothness of the printed object surface or weld two objects together.

3. Printing temperature requirements are different.

The PLA (polylactic acid) printing temperature is 170 to 230 degrees Celsius, and you can print large products without edge warping problems and without using a hotbed. PLA products have a low shrinkage rate and non-toxic printing processes. PLA hardly shrinks, and 3D printers can print large objects without worrying about the finished product hanging, skewed, or damaged from the printing platform.

ABS requires a higher printing temperature, and the printing temperature of ABS filament rolls on the market is generally 220-260 degrees Celsius. In addition, we must heat the hotbed when using a 3D printer with ABS filament, and the hotbed temperature should reach 90-110 degrees Celsius. The glass conversion temperature of ABS (the temperature at which the plastic begins to soften) is 105 degrees Celsius.

Because this ABS filament shrinks a lot during the printing process, the melted material may fall off the printing platform or hang in the air instead of forming on the last/previous layers. 3D Printing with ABS filament must use a heating plate. Therefore, we recommend that you not print in a room where the room temperature is too low. Or you can directly use a closed printer to avoid too much shrinkage due to the rapid cooling of the material.

4. Environmental protection performance of the finished product

PLA is an environment-friendly bioplastic, which will not cause any air pollution in the printing process.  It can be biodegraded by itself under certain composting conditions.

While ABS is a non-biodegradable engineering plastic, ABS materials produce volatile organic carbon when printed, which is toxic and does not smell well. We need to keep ventilated when using ABS to print. If conditions permit, you can use an air purifier to extra the bad smell gas outdoors.

5. Application field of the printed product

The product printed with PLA material has a good glossiness and is colorful. It is used for printing handicrafts, building models, and daily necessities. The 3D model made by PLA is more suitable for display in everyday life than in industry. Although PLA claims to be biodegradable, it generally does not decompose without heating and is water-resistant. Therefore, we can use tools such as PLA to print vases, and it doesn’t matter to put flowers on these vases and put them outside.

ABS products have stable chemical properties, insulation, and chemical corrosion resistance. They can be machined (such as drilling, tapping, etc.), metal plating and spraying, hot pressing or bonding, etc. ABS products are widely used as plastic parts, electronics and electrical appliances, and some popular Lego building blocks. The products made by ABS filament are suitable for industrial manufacturing.

6. Hotbed and printing environment

When printing with PLA filament, there is no need to heat the hotbed. If you want to heat the hotbed,  the hotbed temperature should not be more than 50 degrees Celsius. Why? Because PLA is easy to soften at a temperature of about 60 °, which affects the flatness of the model’s bottom). PLA materials rarely shrink, and even open printers can print large objects without worrying about the finished product hanging, skewed, or damaged from the board. This kind of material is suitable for 3D printing in public places.

When printing with ABS filament, we should heat the hotbed to 110 °. Otherwise, it is easy to warp the edge. The product printed by the ABS filament shrinks quickly, and it will fall off from the printing platform or hangs in the air. In addition, if the printed product is very high, sometimes the whole layer will be peeled off. Therefore, when we use ABS for printing, we must heat the hotbed. In addition, I also recommend that you use a closed printer, or at least do not print in a room where the room temperature is too low, to avoid the payers colling too fast and to decrease shrinkage.

7. About the preservation and price of consumables:

PLA and ABS filaments are usually kept in a vacuum-sealed package. If you do not use the filament roll after opening the packages for a long time, we recommend that you seal the material and store it in a dry place. Please do not expose the filaments to the air for a long time to avoid the filament’s deterioration and maintain its high print quality. The two kinds of 3D printing filaments are available in various colors at roughly the same price. But special consumables, such as PLA mixed with wood or other materials, are more expensive.

Now, let’s summarize what you need to pay attention to when using ABS filament for 3D printing.

The most common problem with ABS is that it is prone to warpage or break/lack of some layers, which is caused by too much temperature change in the extruded/printed material. The material begins to cool and solidify after extruding from the nozzle. When the cooling is too fast, the ABS will contract/shrink too much, the bottom layers will warp upward, and the middle layers will break.

To avoid excessive shrinkage of printed materials, you can try the following methods:

1). Level the hotbed before printing. It is helpful for any consumable material.

2). Make sure the surrounding printing temperature is not too low to prevent excessive shrinkage of printed material.

3). To improve the adhesion between the starting layer and the hotbed by adjusting the temperature and speed. This includes increasing the hotbed temperature, increasing the printing temperature of the starting layers/primary layers, and widening the width of the starting layer. Reduce the printing speed of the starting layer and reduce the height of the layer.

4). Turn off the cooling fan of the 3D print module.

Generally speaking, PLA and ABS have their advantages and disadvantages. We should use specific consumables according to our actual needs. At present, most household 3D printers can support these two kinds of filaments, which is very convenient and practical for us to use both PLA and ABS filaments to meet different printing requirements. I sincerely hope everyone can print high-quality objects and products.