Plastic materials usage is growing across the automotive industry. Some of the statistics says that plastics makes up to 50% of modern automobile volume but weighs only 10%. So, it would have been surprising if design engineers would not have looked at plastics as a means of reduction in cost and weight. One of the main drivers in USA for increasing adoption of plastics in automotive was the Corporate Average Fuel Economy (CAFE) standard and help boost fuel mileage of the vehicle.
Automotive manufacturers started embracing plastic for making many parts of the automotive. Knowledge about plastic components and their manufacturing has become essential for someone who wants to work for an automotive manufacturer or a company which manufactures plastic components.
Let us try to delve into little more details about these plastic components manufacturing.
Reasons to use Plastic/Polymers in automotive
Earlier many automotive components were made up of metals, glass, wood etc. Now these are made from plastic. Here are the reasons.
Lower Cost and Ease of manufacturing
Plastic components can be manufactured within very few stages. Most of the components require only a couple of stages unlike other materials like metal. They can be made at lower cost due to less production time and less involvement of machines.
Plastic components have lesser density and lesser wall thickness compared to any other material. Hence the weight of such components in significantly less. And this is very crucial aspect not only for cars but for manufacturing of ships and aeroplanes too.
Plastic and polymers play a vital role in increasing safety of the car. Seat belts, airbags, thin layer of plastic put between two layers of glass to make windshields are some of the examples. External part like bumper made from polymer can absorb four to five times more energy during the impact as compared to any other alternative material.
The process waste in terms of material being created during machining of plastic components etc. is very less.
Plastic processing is much reliable as compared to other manufacturing processes like sand casting, machining. Here, chances of rejection are less.
Easy creation of many Surface Textures
Typically, the metal components need surface processing after being manufactured. Plastic components do not need such separate surface processing operation. In the main process itself one can obtain plain surface or textured surfaces like hammer tone texture, wrinkled texture, non-gloss texture, leather surface texture etc.
Better scope for Recycling
In case of plastic components, the in-process wastage and other scrappage is easily convertible to a useful component as compared to other materials like metals or wood.
Ease of processing Complex Shapes
Complex and intricate shapes can be easily obtained using plastic materials.
Transparency or Colour Choices
The plastic components can inherently have transparency, opaqueness or any colour combination without undergoing any additional processing.
Enables more innovative designs
Designers use more innovative ideas to enhance functionality of automotive. Paint protection film which is thicker and more resistant to scratches than traditional paint, new-generation lithium-polymer batteries, fuel cells for hydrogen cars are some of the examples of such innovations which use polymers.
Limitations of plastics
Though there are many advantages of using plastic as raw material, it has certain limitations. They are poor in strength, poor thermal stability, poor rigidity etc. Hence, they should be chosen based on the design requirement specifications.
Why it matters to a mechanical design engineer?
Mechanical engineering graduate can get job opportunities in the companies working in different domains like automobile, plastic, heavy machine, aviation etc. The foundation skills which are focused in the selection test and an interview are related to engineering drawing. One need to be good at reading engineering drawing, basic concepts of tolerances and GD&T to clear the CAD test.
Beyond this, it would be unique advantage if one knows about materials and their properties. Company working in plastic domain would surely be interested in knowing what kind of understanding a fresh graduate has about plastics. Knowledge of some of the basic things about plastic materials and design considerations would make you stand out from the crowd.
We will explore some more aspects of plastic product design in the next part. Read 2nd part
What should I do to standout?
Along with your graduation, expanding your knowledge horizon with engineering domains like plastic, casting, sheet metal etc. is very crucial. An easy and certain way of doing expansion of your knowledge horizon is to join a most comprehensive course like Product and Tool Design Engineer from CADCAMGURU.