What is Manufacturing?

In this tutorial, you will first learn about the fundamentals of manufacturing. Then you will learn about various manufacturing industries, manufacturing processes, materials used in manufacturing. You will also read about the different production systems, importance of manufacturing support systems and finally about the current trends in manufacturing.

Contents:

1. What is Manufacturing?
2. Types of Manufacturing Industries
3. Materials in Manufacturing
4. Manufacturing Processes
5. Production Machines and Tooling
6. Production Systems
7. Manufacturing Support Systems
8. Trends in Manufacturing

What is Manufacturing?

Technologically, manufacturing is the application of physical and chemical processes to change the geometry, characteristics and / or appearance of given raw materials to manufacture parts or products.

• The process of achieving manufacturing involves a combination of kinds of machines, tools, energy, and labor.
• The processes are usually carried out in a sequential manner to achieve the desired product.
• Scrap or waste material may be formed in the process which can be recycled or disposed of.

The following diagram shows the manufacturing process from a technical point of view:

The diagram shows us that we start with a starting material based on our requirements. Manufacturing process is carried out with the combination of power, labor, machinery and tooling to give the final processed part. In the complete process scrap and waste material may also be formed.

Types of Manufacturing Industries

Industry is made up of companies and organizations that produce or supply goods and services. The industry can be divided in three categories.

• Primary industries: Primary industries cultivate and develop natural resources, such as agriculture, forestry, and mining.
• Secondary industry: Secondary industries transform the production of primary industry into consumer goods and capital goods.
• Tertiary industries: These industries constitute the service sector of the economy. This sector generally includes both private and government enterprises.

A few examples of these industries are listed in the table below:

Materials in Manufacturing

Engineering materials can be classified into 4 basic categories. The classification is represented below:

• Metals: Metals are minerals or substances that form naturally below the surface of the Earth. Alloys are defined as components that are composed of two or more elements with one being a metallic element.
  Metals and alloys can be classified into 2 types.
• Ferrous Metals: These metals are based on iron. Pure iron has limited commercial use hence it has to be combined with other nonmetals like carbon to improve its mechanical properties. E.g., steel and cast iron. These metals are heavy in nature and are suited for electrical applications due to their magnetic nature.
• Nonferrous Metals: These metals do not have iron as a constituent. Nonferrous metals include the pure metals and alloys of aluminum, copper, gold, magnesium, nickel, silver, tin, titanium. They are more expensive than ferrous metals but have excellent properties like low weight, higher conductivity, and resistance to corrosion.
• Ceramics: Ceramics are defined as composite materials containing different kinds of metals (or semi-metals) and non-metal elements. They can be divided into 2 categories.
• Glass: Glass is non-crystalline and amorphous in nature and the main component of glass is silicon dioxide.
• Crystalline ceramics: Ceramics can be crystalline or semi-crystalline in nature, but they are never amorphous. The primary component in crystalline ceramics is clay.
• Polymers: A polymer, also known as a macromolecule, is a big molecule made up of numerous subunits. They are classified into 3 categories.
• Thermoplastic Polymers: Polymers that can be melted and recast practically forever are known as thermoplastics. When heated, they become molten and solidify as they cool. E.g., polyethylene, polystyrene, polyvinylchloride.
• Thermosetting Polymers: A thermosetting polymer, also known as a thermoset or thermosetting plastic, is a polymer made up of cross-linked molecules or molecules with a lot of branches. When heated, these soft solid or viscous polymers undergo substantial cross-linking in molds, resulting in irreversibly hard and insoluble products.
  E.g., phenolics, amino resins, and epoxies.
• Elastomers: A polymer with the property of elasticity is known as an elastomer. To put it another way, it is a polymer that deforms under tension and then returns to its previous shape once the stress is relieved. E.g., natural rubber, neoprene, silicone.
• Composites: Composites are made up of two or more constituent materials that have varied physical and chemical properties. The matrix and fiber are the two main components of a composite. The matrix serves as the material’s base material, while the fiber serves to reinforce it. They are classified into 3 categories:
• Metal Matrix Composites: Metal matrix composites, as the name implies, are made up of metal fibers or particles encased in a metal matrix.
• Ceramic Matrix Composites: Ceramic matrix composites (CMCs) are made up of ceramic fibers or whiskers that are embedded in a ceramic matrix.
• Polymer Matrix Composites: Fibers incorporated in an organic polymer matrix make up polymer matrix composites.

Manufacturing Processes

A manufacturing process is a planned operation that alters the physical and/or chemical properties of a work material to increase its value.

There are two types of manufacturing operations:

• Processing Operation: A processing action takes a work material from one stage of completion to the next, bringing it closer to the ultimate desired result. It adds value to the basic material by altering its geometry, qualities, or appearance. E.g., casting.
• Assembly Operations: An assembly operation unites two or more components to form a new entity, which is referred to as an assembly or subassembly. E.g., welding

Production Machines and Tooling

Machine tools are power-driven machines used to operate cutting tools previously operated by hand. All machine tools have a way of limiting the workpiece and guiding the movement of the machine’s elements.

The following table gives information about some of the processes and the equipment used for it.

Production Systems

The factory, as well as the production, material handling, and other equipment in the factory, are considered production facilities. The way the equipment is positioned in the factory (also called the plant layout) is also part of the facilities.

They are classified into 3 categories based on the type of facilities required:

1. Low-Quantity Production: In low quantity production, quantities in the range of 1 to 100 units per year are produced. They are also called job shops which produce specialized and customized products in small quantities.
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   Rather than moving the product to the equipment, workers and processing equipment are transported to the product (fixed-position layout). These include products like ships, aircraft, locomotives, and heavy machinery.

2. Medium Quantity Production: In medium quantity production, quantities in the range of 100 to 10,000 units annually are produced. They are classified into batch production and cellular manufacturing.
• When product variety is hard (products differ substantially), batch production is the typical way, in which a batch of one product is produced, then the facility is switched over to make a batch of the next product, and so on.
• When the product variety is soft (small differences between products) cellular manufacturing is used where processing or assembly of different parts or products is accomplished in cells consisting of several workstations or machines.
• These include products like furniture, clothing, jewellery, food, and drink.
3. High Quantity Production:Production quantities are 10,000 to millions of units in high quantity production. They are classified into Quantity production and Flow line production.
• If there is mass production of single parts on single machine or small numbers of machines, then it is called Quantity Production.
• In Flow line production, multiple pieces of equipment or workstations are positioned in a sequential order on a flow line, and the work units are physically moved through the sequence to finish the product.
• These include products like cars, paper, refrigerators, and television sets.

Manufacturing Support Systems

It is the company’s set of procedures for managing production and resolving technical and logistical issues that arise during the ordering of materials, moving work through the factory, and ensuring that products satisfy quality requirements.

Manufacturing support functions are often carried out in the firm by people organized into departments such as the following:

• Manufacturing engineer: The manufacturing engineering department is in charge of planning manufacturing processes, which includes determining which techniques should be employed to create parts and assemble products.
• Production planning and control: This department is responsible for solving the logistics problem in manufacturing.
• Quality control: A business’s quality control (QC) procedure strives to ensure that product quality is maintained or enhanced and that the customer’s expectations are satisfied.

Trends in Manufacturing

This section looks at some of the current trends affecting materials, processes, and systems used in the manufacturing process. Technological and economic considerations are driving these shifts taking place all over the world.

The discussion is organized into the following topic areas:

1. Lean production and Six Sigma,
2. Globalization,
3. Environmentally conscious manufacturing, and
4. Microfabrication and nanotechnology.

1. Lean production and Six Sigma: These are two programs targeted at increasing production efficiency and quality. They respond to customer requests for products that are both low in cost and high in quality.
2. Globalization: Globalization refers to the acceleration of global movements and exchanges (of people, goods, and services, capital, technologies, and cultural practices).

   Globalization has the effect of promoting and increasing interactions between different locations and populations around the world. It has significantly affected the manufacturing sector.

3. Environmentally conscious manufacturing: Environmentally conscious manufacturing refers to initiatives that aim to determine the most effective use of materials and natural resources in manufacturing while minimizing negative environmental effects.

   It aims to maintain appropriate housekeeping practices, prevent pollutants from escaping into the environment, reduce material waste in unit operations, and recycle rather than disposing waste materials.

4. Microfabrication and nanotechnology: Microfabrication refers to the processes needed to make parts and products whose features sizes are in the micrometer range. E.g., microsensors, CD, DVD Nanotechnology refers to materials and devices with feature sizes in the nanoscale range. E.g., flat screen, TV monitors, and cancer drugs