What Is a Plastics Processor?
Plastics are essential materials in our daily lives, and comprise various types of resins. For instance, polyethylene (PE) is used in plastic bags, ABS resin in the housing of home appliances like TVs and refrigerators, and polystyrene (PS) in Styrofoam.
A plastics processor transforms these resins into products with the desired performance and shape. The processing conditions vary depending on the type of processor and the intended result. Key processing methods include injection molding, extrusion molding, vacuum molding, and plastic cutting. Other methods are punching, optical molding, blow molding, and vacuum casting.
Types of Plastics Processors
As mentioned, plastics processors use a variety of methods, with processing conditions selected based on the plastic’s hardness, melting point, flowability, and other properties, as well as the final product’s shape and physical properties.
Processors can be broadly classified into cutting and molding types. Cutting is used for small-lot, high-variety production, while molding is more suited for mass production.
When heated, plastics become fluid and can be poured into molds. A 3D printer, for example, reads 3D data and discharges heated, fluid resin to create modeled objects.
1. Cutting Process
In cutting processors, hardened plastics are shaped using lathes or saws. Suitable for small-lot, multi-variety production, this method processes each piece individually and is ideal for complex shapes and a wide range of resins, including super engineering plastics.
2. Molding Process
Molding involves heating plastics and injecting them into molds, then cooling to solidify. This method is efficient for mass production. It’s used for various plastics, including polyethylene, polyamide, polystyrene, and polycarbonate. Molding processes are further divided into injection, extrusion, and vacuum molding, selected based on the plastic type and desired product quality.
- Injection Molding: Used for a wide range of products, from smartphone cases to automotive components. Resin is heated, injected into a mold, then cooled and solidified.
- Extrusion Molding: Similar to injection molding, but used for products like pipes and films. The resin is shaped, extruded, then cut to size.
3. Plastics Processors Using Machining Centers
Machining centers, controlled by numerical units, are used for complex, high-precision tasks. They can automatically change tools, performing operations like milling and drilling. These machines are suitable for small materials and 3D processing. The process involves creating CAM data from drawings, setting tools, and machining the material, often using devices like vices for stability.
Other Information on Plastics Processors
Different machines are used based on processing requirements. Cutting involves machines like lathes and mills, while molding integrates pressurizers and molds. Initial costs for molding are high due to mold fabrication, but it’s suitable for mass production. Press machines are also used in plastics processing for tasks like drilling and bending.