Manufacturing has a history of several thousand years and is driven by several approaches. Each such process results in the well-defined changes in the physical and chemical characteristics of the materials. Traditional manufacturing processes include casting, moulding, extrusion, vacuum forming, machining, welding and many other processes. Which manufacturing process to select for production depends on the nature of the finished product. Considerations of mechanical properties like strength, ductility, fatigue, thermal expansion and other mechanical properties desired play an important role in selecting the manufacturing process and the material. Oftentimes, complicated products require more than one process to manufacture them. For example, a steering wheel in an automobile can be die-cast from plastic, but assembling a chassis involves multiple mechanical operations.
Direct digital manufacturing, also called as digital 3D printing or additive manufacturing, has changed forever the way things are manufactured. The term direct digital manufacturing implies the process of going from a digital blueprint of a product to a finished physical product. The technology uses digital profiles generated by computers to create real-world objects ranging from simple toy pieces to complex fighter jet parts. In fact, 3D printing has already been extensively adopted by many industries, including mechanical engineering and manufacturing product development, apparel, toy, construction, medical devices, and even human organs.
One of the most important advantages direct digital manufacturing offers manufacturers is the accuracy with which costs and lead times can be reliably predicted. Since there is no die-casting or other intermediately processes involved, direct digital manufacturing allows manufacturers more budget control. Direct digital manufacturing has been heralded as a breakthrough in manufacturing because of its ability to directly fabricate CAD models without the need for expensive tooling, moulding or machining, and freedom to create complex geometries which are just impossible with traditional manufacturing methods. Direct digital manufacturing also present users with an entirely unique perspective on using material; they are no longer analog things, but digital assets whose construction and organization are largely subject to the capacities of current software.
What really separates direct digital manufacturing is the freedom of design it offers. In conventional manufacturing, the design team needs to consider the manufacturing constraints first and then design accordingly. Let’s say a designer has an innovative idea about creating acurved steering wheel for an automobile that is extremely ergonomic. It can be extremely beneficial for drivers who need to undertake a long journey. Since driver fatigue is one of the main causes of road accidents, this new design can prove to be a boon by increasing the comfort level of the driver and reducing fatigue. However, if the production team says that they just do not have any tool sets that will produce a curved steering wheel, it simply cannot be manufactured. Direct digital manufacturing frees designers to design exactly the way they want, without having to worry about the manufacturing concerns. If they can create a 3D printing file, it can be manufactured. Design is no longer constrained by the limitations of conventional manufacturing processes. This frees the product development team to focus completely on designing a part exactly the way they envisage it. An added advantage this freedom offers is that products not only function better; they look better as well.
Just like traditional manufacturing, there are different 3D printing technologies. And just like traditional manufacturing, each technology has advantages and disadvantages. The present 3D printing technologies include Stereolithography(SLA), Digital Light Processing(DLP), Fused deposition modeling (FDM), Selective Laser Sintering (SLS), Selective laser melting (SLM), Electronic Beam Melting (EBM), Laminated object manufacturing (LOM) and variants of this basic technologies. Which 3D printer to choose depends entirely upon the manufacturer’s objectives.
Advantages of Direct Digital Manufacturing
3D printing is the logical choice for forward looking industries. They provide various advantages over traditional manufacturing methods.
Freedom to Design: Since the entire process is digital, ideation is not a constraint. The design team can reiterate a design at the prototype stage itself, without having to worry about manufacturing cost. In a traditional manufacturing process, each design tweak usually means adjusting the jigs and fixtures or changing the die completely. This can prove to be a costly affair.
Green manufacturing: Traditional manufacturing usually entails chipping away at material to give an object shape. Not only does this waste raw material, it also expends lubricants needed to cool the cutting tools. If they are not disposed of properly, these coolants can prove to be a source of pollution.
Variety of Printing Material: The choice of printing material 3D available is simply mind blowing. From metal and plastics to food material, you can 3D print almost anything. And with speciality multi-material 3D printers like Stratasys J, Objet and Connex series, the printing industry has scored once more over traditional manufacturing.
Direct digital manufacturing has proved to be a boon especially in areas like automobile sector, aerospace sector, defence sector and the dental sector among others.
The Constraints of Direct Digital Manufacturing
While there are many advantages of direct digital manufacturing / 3D printing, there are still some constraints that the 3D printing industry needs to overcome. Today’s 3D printers, especially from pioneers like Stratasys, print 3D objects faster than traditional manufacturing. However, it is ideal for small batch customized productions rather than volume manufacturing as of date.
Another constraint they have is small printing area. Both these constraints have so far prevented 3D printers from being used for mainstay manufacturing. However, as technology progresses, there is a measurable change in the speed of printing. Each newer generation of 3D printers is faster and more accurate than its predecessor. 3D printing stalwarts like Stratasys are working to close the speed gap. There is progress in the field of large scale or big area 3D printing as well. With this new printing technology, it is now possible to 3D print tools like patterns for foundry industry, jigs, and fixtures to aircraft wings, turbines, submarine hulls or even entire shells of small vehicles.
As more and more companies enter the 3D printers market due to the huge benefits direct digital manufacturing offers and the coming to age of industry 4.0, there are exciting times ahead for the 3D printing sector in India and the world.