How Is Plastic Made? The Journey from Raw Material to Pellet

The process begins with naphtha obtained by refining crude oil (or light hydrocarbons such as ethane obtained from natural gas). This is the basic raw material for polyolefin production.

Naphtha or ethane is broken down at high temperature, in a process called 'cracking,' into smaller molecules — monomers such as ethylene and propylene. These monomers are the basic building blocks of PE and PP (see the 'What Is PP' and 'What Is PE' articles).

The monomers bond together into long-chain polymer molecules in a reactor in the presence of catalysts (such as Ziegler-Natta or metallocene) — this process is called polymerization. The temperature, pressure and catalyst type in the reactor determine the resulting material's MFI, density and other properties.

The polymer coming out of the reactor is generally in powder or molten form. It is melted in an extruder, drawn into thin strands, then cooled with water and cut into small cylindrical or spherical granules (pellets) — this is the final physical form you see in our catalog and that we deliver in bags/big-bags.

These pellets reach processing companies (our customers), who convert them into final products (film, pipe, container, yarn, etc.) using methods such as extrusion, injection molding or blow molding.