3D printing is sometimes promoted as a way to help the environment. In a future blog we’ll explore how the different materials are recycled. For this blog I’ll explore how 3D printing impacts the environment from factory to home 3D printer. I want to focus on the carbon footprint that filament and 3D printing has compared to a commercially made item.

A Tale of Two Sink Strainers

I wanted to compare similar utilitarian items that can be found in the common sink.

After the kitchen was remodeled, I lost the stainless steel sink strainer that came with the sink. I 3D printed a replacement sink strainer that I designed from a parametric file in Thingiverse customizer. After printing a batch of 4 3D printed Sink Strainers (3DSS) in PETG and Colorfabb nGen, I’ve used them daily in the kitchen sink. I found that the 3D printed strainers withstand 4-6 months of daily use. I’ll compare the carbon footprint and impact to a commercially made sink strainer (CMSS). For each section I’ll give a point to one based on which has the least impact on the environment.

Materials impact on Environment

In looking at the material requirements for both sink strainers, 3D filament has an advantage out of the gate. While PETG is a petrochemical plastic, the energy required to produce it into filament is less than the energy and environmental impact of the CMSS. The CMSS requires steel and synthetic rubbers which are energy intensive. Score: 3DSS : 1 CMSS : 0

Production

The energy required in production is far different. A spool of filament takes less energy and time to produce then making the CMSS. By leaving the filament as a stock material, the 3DSS does not use any energy at this stage. On the other hand, a factory stamping out the stainless steel parts and injection molding synthetic rubber parts is another energy intensive step. Score: 3DSS : 2 CMSS : 0

Packaging

A major factor in this is how each item is packaged. Most of the plastic waste on the planet is single-use packaging material.

3D printing loses out here. While there are attempts now to reduce the amount and type of spool packaging filament has an issue with the amount of packaging.

A spool of filament is shipped inside of a vacuum sealed bag, usually inside a cardboard box. The total plastic from the spool, bag and box is far more then what you get with the CMSS. The CMSS may be packaged for retail on a minimal paperboard card with a few twist ties. While all packaging material may be recyclable, the amount that is shipped with filament is greater.

Score: 3DSS : 2 CMSS : 1

Shipping

Another major consideration is the fuel and transportation impact of shipping these items. They are both commonly imported from China. After that, they take two different paths.

For 3D printing filament, it is commonly shipped to the consumer. This reduces the amount of fuel used when it goes direct to home. Shipping one spool of filament that can produce 20-40 objects at home drastically cuts the fuel that would otherwise be used in shipping those items individually.

In contrast, the CMSS is shipped to a retail store, where the store also uses energy to store, shelve and sell the CMSS to the consumer. In addition, the consumer uses more of their energy to transport the CMSS home from the retail store. Score: 3DSS : 3 CMSS : 1

3D Printing the Strainer

In this step the consumer 3D prints the strainer with the raw filament. This step does require some energy to download the file and 3D print the item. In contrast the CMSS is ready to drop into the sink. If the homeowner gets their energy from a renewable source, the carbon footprint is minimal. But for this I looked at the worst case option, with printing having some carbon footprint from energy use.

Score: 3DSS : 3 CMSS : 2

Waste Impact on the Environment

In terms of waste the 3DSS has the CMSS beat. 3D printing has a wisp of plastic waste from the priming line. As it is printed on demand, there is no packaging related to the part printed. In comparison, the CMSS comes from the store with some packaging that has to be recycled.

Score: 3DSS : 4 CMSS : 2

Material Life Span

The 3DSS has a shorter life span. In my experience they last 4-6 months; compared to the CMSS which last 1-2 years before the rubber section degrades. For anything 3d printed you will have to wash the 3DSS by hand, while the CMSS you can wash in a dishwasher.  Score: 3DSS : 4 CMSS : 3

Considerations

This narrative of two sink strainers illustrates the typical path that they both take from factory to home. 3D printing the sink strainer is better for the environment then buying a commercially made one. With further improvements in 3D printing, the carbon footprint can be further reduced with 3d printing. While it is not a perfect way now to reduce our carbon footprint, 3D printing can be combined with other technologies to drastically reduce our carbon footprint. In future blogs I’ll explore ways to lower the environmental impact of 3D printing.

The strength of 3D printing is that you can print on demand just the items that you need at home. This greatly reduces the carbon footprint of transporting multiple items to your home.

---

This is part 1 of a series on 3D printing and the environment.

Pt.2 will look at how to recycle common filaments.

Pt.3 will cover how to improve the impact of 3D printing.