Basic Materials and Processes
Natural resources and man-made products drive the industrial economies. The global reach of metals, plastics, rubber, and wood are well known. All these materials are naturally mined or chemically processed. Different types of products are designed from these indispensable substances. Metal casting, rubber and plastic extrusion are some of the popular shaping methods. Heavy machines, heat, and pressure are vital in these processes.
Metals and Alloys
Iron, platinum, tungsten, steel, gold and silver are metallic in nature. These ferrous and non-ferrous metals have wide spread applications. Metallic products are either handcrafted or manufactured in factories and firms. Some of them are combined to create alloys such as tin, copper, brass and zinc. They are used in the creation of commercial, domestic and industrial items.
Plastics belong to a category of chemical compounds called polymers. They are found in nature in the form of protein, cellulose, DNA, silk, and wool. Synthetic or man-made polymers are nylon, Teflon, polyester, PVC, polyethene. These compounds are famous for their strength, durability and ease of maintenance. Plastic extrusion is carried out to mould the malleable substance into different shapes.
Rubber and natural timbre are extracted from trees in the forests. Entire homes are built from these natural timbres or wood. These natural resources are elastic, robust, and durable. Their malleability is exploited to create a wide range of objects and furniture.
The natural ore is mined and processed to acquire the raw materials. They are heated, melted, cooled, washed, and purified in a furnace. The metals are transported to the mills and manufacturing depots. They are stretched, cut, sharpened, polished, cast, and shaped. Metals are cast into different types of plates, bars and ingots. Plastic extrusion is the ideal solution to form polymer products.
High Volume Manufacture
Basics of Extrusion – Plastic materials can be shaped or formed with the help of dies. A series of dies are also used in the creation of complex sizes and shapes. Tools and machines are also used in large volume manufacture. The physical and chemical properties of the compounds are well understood. The shaping process, known as plastic extrusion, is mechanical and streamlined.
- Shape or form is defined or delineated by a constant cross-section or profile.
- The plastic is forced through dies in different types of extrusion processes.
- These methods can be categorized into hot, cold, and warm techniques.
- Other procedures are labelled as impact, direct, indirect, and combination processes.
- Thin or thick profiles, as well as solid and hollow products, are created.
- Dies are metallic discs and extrusion sizes are in terms of a smallest circle’s diameter.
- All metallic extrusions have unique parameters and are either slow or fast.
- Plastic extrusion is the conversion of thermoplastic into various shapes and profiles.
- Nylon, PVC, and polyethene are the most regularly extruded materials.
Thermoplastic Process – Plastic is a soft and supple material that can be shaped at will. Its malleability is reflected in fences, railings, and frames. Other applications include films, sheets, coatings, tubing, and insulation.
- The thermoplastic material is converted into a molten and viscous fluid.
- Afterwards, it is carefully extruded into pipes, rods, bars, and tubes.
- Plastic extrusion machines have parts like a hopper and die assembly.
- Other main components are a helical screw and heated feed barrel.
- The material is fed, heated, and dragged forward through four different zones.
- These are typically known as a feed, transition, mixing, and metering zones.
- The process involves compression, mixing, force pumping and die to assemble.
- Profile and blown film extrusion are the two primary high-volume methods.