Plastic Vs. Metal Fabrication – Advantages and Disadvantages
Curious about the differences between plastic and metal fabrication? Consider this.
According to Thomas Net:
Fabrication refers to any process that cuts, shapes, or otherwise forms a material into an end product, and this article covers the advantages and disadvantages of plastic over metal fabrication, and vice versa. The type of fabrication method used to produce a particular item depends on a wide range of factors, including the products purpose, appearance, and available budget. Before determining whether plastic or metal fabrication is appropriate for a particular job, it is important to first understand the potential advantages and disadvantages of each option.
Types of Fabrication Processes
Both plastic and metal fabrication involve a wide range of distinct manufacturing processes. This range allows for a considerable number of customization and selection options in component design. Some of the more common fabrication processes include:
Cutting: This involves various tools or machines removing excess material from a workpiece to meet size and shape requirements. Band saws and cutting torches are two examples of cutting devices.
Forming: This process uses deforming equipment, such as hydraulic brakes, to bend or press products at a specified angle.
Machining: Machining processes, which include lathing, milling, drilling and honing, use automated or manually controlled equipped to shape material.
Welding: Welding is the process of joining two or more workpieces by applying heat or pressure to form a single product.
Advantages of Plastic Fabrication
Though the results of plastic fabrication greatly depend on the unique characteristics of the type of plastic used (acrylic, Plexiglas, nylon, etc.), the process itself has several advantages, which include:
Ease of forming: Due to its low melting point and high malleability compared to other materials, plastic can be formed into basic and complex geometries with relative ease.
Reduced finishing: Unlike most metals, plastics can be colored prior to fabrication, eliminating the need for certain post-treatment processes, such as painting.
Faster production: Plastic fabrication often involves quick cycle times and fast turnover rates.
Lighter weight: Plastics typically weigh less than metals of comparable dimensions.
Chemical resistance: Plastics are generally less susceptible to damage from chemicals or chemical reactions, such as oxidation or rusting, than metals.
Disadvantages of Plastic Fabrication
Although plastic is useful for fabricating a wide range of parts, it also has its share of limitations as a production material. Some of the disadvantages of plastic fabrication include:
Limited wear resistance: Plastic has a low resistance threshold for elevated temperatures, acidity, and other corrosive elements.
Structural weaknesses: Most plastics are unsuited for applications requiring high structural strength, such as heavy equipment components and most building materials.
Advantages of Metal Fabrication
Like plastic fabrication, metal fabrication depends largely on the family and grade of metal used in production. Some of the more commonly fabricated metals include steel, magnesium, iron, aluminum, copper, and nickel, each with their own various grades. Metals generally provide the following advantages over plastic fabrication:
Heat resistance: Metals typically have a higher melting-point and are less likely to degrade under elevated temperatures.
Improved strength: Metal grades tend to be stronger, harder, and more durable than their plastic counterparts.
Versatility: Metal can be fabricated through a wider range of processes, including casting, deep drawing, welding, forging, soldering, and chipping.
Cost-effectiveness: Metal is usually a cost efficient option, particularly in high-volume or long-term production runs.
Disadvantages of Metal Fabrication
Despite offering numerous benefits, metal is not ideal for every application. Some of the disadvantages of metal fabrication include:
Secondary operations: Metal fabrication is more likely to require post-fabrication processes, such as finishing, painting, and deburring, which can be time-consuming or costly.
Design limitations: The viscosity and molten flow behavior of some metals are not suited for crafting highly complex geometries or shapes.
High start-up fees: metal tooling costs are typically more expensive than comparable plastic fabrication tooling.
Choosing a Specific Fabrication Process
Once you have determined whether plastic or metal fabrication will better meet your project needs, the next step in the production process is to choose a specific shaping or forming process. Some frequently used fabrication techniques and their common applications are:
Lathing: Lathing is a cutting method that uses a rotating work table and separate blade to cut, drill, knurl, or etch the material. Lathing is best suited for products that are symmetrical around an axis of rotation.
Drilling: This process employs a drill press to bore holes into a product. It is effective for creating uniform, circular cuts.
Milling: Like drill presses, mills bore holes through material, but with a sideways cutting motion. They are a good option for creating asymmetrical or non-circular cuts.
Honing: Honing involves multiple rotating tips that enlarge existing holes to exact sizes. It is useful for making products that require large circular cuts, such as engine cylinders.
Grinding: Grinders apply an abrasive wheel to surface treat material or create faint cuts in the product. Grinding is beneficial for applications that require smooth surface textures.