List of Manufacturing Processes

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The products that we see and use every day go through highly complex manufacturing processes. These manufacturing processes require people with a wide range of skills and knowledge. They need to have expertise on the wide variety of tools, equipment, computers, automation, robots (increasingly significant), and software.

Different products call for different types of manufacturing processes. Each manufacturing process has its advantages and disadvantages. Understanding the various processes is important to match manufacturing requirements with the latest developments and technologies. Understanding the specific manufacturing processes is also important in order to maximize shop and plant layouts as well as to maximize the efficiency of a business.

Let us look at the main types of manufacturing processes in little more detail:

Casting

Casting is a type of molding process. It is a method of manufacturing in which a material is liquefied by heating it and then the molten form is poured into a mold. The melted material then cools down and solidifies to take the shape of the mold. Thus, any desired shape can be produced by making sure that the mold is of the desired specification.

Different types of casting processes include centrifugal casting, die casting, continuous casting, and so on. Making the mold can sometimes be expensive. Sometimes additional processing is performed during the melting stage in order to tweak chemical properties of the material.

Other types of molding

Besides casting, there are other types of molding processes. One of the popular ones is called injection molding. Used extensively with thermoplastic materials, injection molding involves injecting the melted raw material (mostly plastic) into a cavity of a tightly held mold. The mold can be designed in a shape that is required by the end product.

This process is great when the same type of product is to be made repetitively and provides economies of scale. However, the mold making process is expensive, hence small quantities are not recommended with this process.

Blow molding is another form of molding which is used to manufacture hollow products. First, the material (mainly plastic) is melted and formed into a tube-like shape with a hole on one end. This tube-like melted material is held in a mold. Then air is blown through the hole with high pressure to push out the melted plastic and take the shape of the mold in which it is held. After the melted material cools down, the mold is opened up and what you get is the end product. Commonly used items such as bottles and pipes are made using blow molding.

Compression molding is also a popular method to manufacture consumer goods and durables. In this method, plastic or rubber is used in a preheated form. The preheated material is poured into a mold which is then shut tight and pressure is applied to make sure that the material inside makes contact with all areas of the mold. This “compression” is what gives the process its name. Things like rubber boots and tires of automobiles are manufactured using compression molding.

Forming

This type of manufacturing process is used to shape and form a material, say metal, by pressing, bending, spinning, or stretching the material. Some examples of forming processes are forging, rolling, pressing, bending, coining, and stamping. There is no cutting, shredding, or breaking of any material. Rather, metal presses and dies are used along with some punching tools.

This process can turn out to be expensive because making dies is not cheap. Other apparatus is also not cheap.

Along with forming, another process that does hand-in-hand is shearing. This process involves cutting of sheet metal using blades. The process is sometimes known as die cutting. Shearing is used commonly on materials like bronze, brass, stainless steel, and aluminum.

Joining

Manufacturing often requires components or parts to be joined together. These joints can be achieved by using bolts to fasten two components together or by welding the two together. Both approaches have their benefits and disadvantages.

Welding leads to a lighter weight of the final assembly and is cheaper as well. However, there are considerations such as load factor, operating environment, etc. which may lead to fastening as the preferred method for joining.

Another form of the joining process is the usage of adhesives. Manufacturing of cardboard boxes and paper-based print material often uses adhesives in its manufacturing process.

Machining

Machining is performed using relatively immobile tools in order to shape and detail solid structures, mainly metals. Machining often involves removing extra material from a “work-in-progress” piece. Tools like rotating wheels, shears, drills, and saws are used to machine parts that are under-production. Lasers are also used at times to cut metal pieces using high-energy beams of light.

A very popular form of machining involves the use of CNC machines. These are computer controlled machines that help machine products using lathes, grinders, routers, and mills. Plastic, as well as metal products, can be machined using CNC machines.

A computer program monitors the position and velocity of the machining tools and a feedback loop ensures that the machine knows where it currently is and where its next position needs to be. Highly complex and intricate designs can be achieved with high precision using CNC machines. Because of the automotive nature of CNC machines, they can machine products with high speed and reduce production time. Hence, they provide a reliable and economical alternative to traditional machining processes.

3D printing

A relatively new form of manufacturing process is one involving the use of 3D printers. It uses a computer program to transform any three-dimensional object or model into multiple thin cross-sectional layers. The 3D printer then prints each of these cross-sectional layers over and over, thus re-creating the original object or model.

3D printing is a form of additive manufacturing, which is very different from subtractive manufacturing. Subtractive manufacturing involves cutting or hollowing out material. 3D printing is additive because it repeats laying down successive layers of cross sections, thus adding to the component being made. There is no subtraction or removal of material involved.