Polyethylene is a thermoplastic, meaning it becomes pliable when heated and rigid when cooled. This particular polymer is synthesized from long chains of ethylene monomers composed of carbon and hydrogen and forms double covalent bonds in many structural configurations. Because it is available in many forms, polyethylene is the most commonly used plastic.
Annual production rates for this plastic alone are approximately eighty million metric tons. Such a large number is necessary to accommodate the incredible diversity of objects made from polyethylene.
Quick links to Polyethylene Manufacturers Information
Products Made from Polyethylene
- Packaging Sheets
- Shower Curtains
- Wire Insulation
- Plastic Bags and Containers
- Bulletproof Vests
- Artificial Knees and Hip Replacement Components
Industries Using Polyethylene
Due to its resistance to water, acids, alkalis, solvents, and chemical corrosion, polyethylene is popular in:
- Food and Chemical Processing
Applications of Polyethylene
While this plastic is non-biodegradable, it is recyclable; it can be:
Additionally, researchers have been developing new techniques aimed at synthesizing polyethylene from components found in sugarcane to create bioplastics.
Types of Polyethylene
While bioplastics continue to be studied, most polyethylene is synthesized from ethylene, though several different methods for this are possible. For example, radical polymerization, anionic addition polymerization, ion coordination polymerization, and cationic polymerization are all used in producing PE through heat and pressurization. As each process results in a slightly different type of polyethylene, the plastics are classified based on density and branching or crystallization.
The three main categories are:
- High-Density Polyethylene
- Which has a melting point in the range of 120 to 130°C.
- Low-Density Polyethylene
- Which melts at around 115°C.
- Medium-Density Polyethylene
There are ten different divisions, including ultra-high density and very low density, but the main three will often suffice. Polyethylene manufacturers utilize these polymer resins forming them into plastic rods, sheets, and films through injection molding, casting, and extrusion. While stock forms such as these may sometimes be used as the finished product, most will undergo additional operations. Secondary processes employed on plastic materials include drilling, welding, fastening, turning, milling, and precision machining. Therefore, it is important to consider both the manufacturing processes and finish product when selecting a polymer.