How is hdpe plastic made

One of the main ways that a factory can get ethylene gas is by isolating a substance called ethane from natural gas. The ethane then serves as the raw material for a process called steam cracking, where steam and extreme heat are applied to the ethane to rearrange intramolecular bonds in the ethane and create ethylene. Next, those ethylene molecules are combined polymerized into chains of polyethylene, which combine in a high-density arrangement with the addition of a chemical called a Ziegler-Natta catalyst.

The HDPE is now a viscous resin that can be molded into whatever solid product it is needed for. The chemical is pumped into a series of wide, shallow board-like metal troughs.

Instead of being allowed to cool, the chemical is cooked at a low heat to allow for the release of captured air and oxygen. From here, the troughs drain into a series of upright metal molds which contain shredded wood fiber. Once allowed to cool for roughly eight hours, the HDPE boards can be shipped to retailers and wholesalers. Blow molding is identical to the production of wood-plastic boards up to the point that the HDPE drains from the sitting troughs.

It is kept in an air-tight heated tank, where a valve puts measured dollops of it onto the heads of a series of air compressors.

Each compressor fits into a metal mold shaped like a bottle. While the compressor pours air into the mold, ballooning out the HDPE into the mold, another compressor functions to pump air out of the mold so the HDPE fits perfectly. Even cereal box liners. The list of uses is huge remember: versatile and popular.

If you flip over your bottle of laundry detergent, it probably has the number 2 imprinted, surrounded by a chasing arrow. The code was designed decades ago to help get plastics recycling off the ground although today community recycling programs are less likely to ask for plastics by the resin code number than in the past. Thanks to collective efforts tracking back to the s, when plastics recycling really started to grow, HDPE has become quite skilled at evading landfills.

Nearly all curbside recycling programs today in the U. Over million milk jugs are recycled each year in the making of HDPE recycled plastic. HDPE plastic is the most environmentally stable of all plastics — giving off no harmful fumes into the environment. Manufacturing HDPE plastics requires only a fraction of the energy required to produce steel from iron ore, further contributing to its classification of being Eco-friendly.