India’s first 3D-printed post office inaugurated in Bengaluru: How does 3D printing work?

Subject: Science and Technology

Section: Msc

Context:

India’s first 3D-printed post office was virtually inaugurated by Union Minister Ashwini Vaishnaw in Bengaluru’s Cambridge Layout on Friday (August 18).

Details:

Multinational company Larsen & Toubro Limited built the post office with technological support from IIT Madras under the guidance of Professor Manu Santhanam.
Its construction was completed in just 43 days — two days ahead of the deadline.

What exactly is 3D printing ? And how do 3D printers work?

Invented in the 1980s, 3D printing burst into the mainstream around the 2010s, when many thought it would take over the world.
The technology at the time was expensive, slow and prone to making errors.
In recent years, some of these flaws have been done away with, making 3D printing more prevalent than ever before.

Concept of 3D printing:
- 3D printing, also known as additive manufacturing, is a process that uses computer-created design to make three-dimensional objects layer by layer.
- It is an additive process, in which layers of a material like plastic, composites or bio-materials are built up to construct objects that range in shape, size, rigidity and colour.

Working mechanism:
- A personal computer is connected to a 3D printer.
- Design a 3D model of the required object on computer-aid design (CAD) software and press ‘print’.
- The 3D printer does the rest of the job.
3D printers construct the desired object by using a layering method, which is the complete opposite of the subtractive manufacturing processes.
- Subtractive manufacturing process involves carving out a desired product out of a large object. Example: Sculpture from a big piece of marble, monoliths out of a big rock etc.
- In the layering method, objects arebuilt from the bottom up by piling on layer after layer until the object looks exactly like it was envisioned.

What objects can be built using 3D printers?

These machines are capable of printing anything from ordinary objects like a ball or a spoon to complex moving parts like hinges and wheels.
One could print a whole bike – handlebars, saddle, frame, wheels, brakes, pedals and chain – ready assembled, without using any tools.

Use of 3D printing in Space sector:

The Agnilet engine (developed by Space Startup- Agnikul) is an entirely 3D-printed, single-piece, 6 kN semi-cryogenic engine.
- The engine, which uses a mixture of liquid kerosene at room temperature and supercold liquid oxygen as propellant, was tested last year at the Vikram Sarabhai Space Centre in Thiruvananthapuram.
In 2021, Skyroot had successfully demonstrated the country’s first privately developed cryogenic engine, Dhawan-1, which too was completely 3D printed, using a superalloy, by a process that cut the manufacturing time by 95 per cent.

Are there any concerns about 3D printing?

While it does allow engineers to reiterate designs faster than with conventional manufacturing techniques, it is not as scalable.
With conventional techniques, once a design has been set, multiple copies can be made much faster.
3D printing is still slow if you compare it to injection moulding or planar-based manufacturing where you can manufacture millions of pieces every month. Soit is not meant for manufacturing in large volumes.

Other challenges include:
- Equipment costs
- Limited materials available
- Post-processing requirements
- Manufacturing costs
- Lack of in-house additive manufacturing resources
- Lack of expertise and/or training among workforce/employees
- Limited repeatability (accuracy from build to build)
- Lack of formal standards
- Lack of proven documentation of additive manufacturing’s capabilities
- Software development and capabilities
- Longer production timelines
- Limited recyclability
- Risk of litigation/legal implication
- Data storage requirements