First invented by Canadian inventor Harry Wasylyk in 1950, trash bags are a 20th century miracle! Before them, we were just throwing trash, at best, into filthy metal cans, and at worst, directly into the ground or ocean. But following WWII, Wasylyk was experimenting with a new waterproof, stretchy material called polyethylene. You can learn more about the history of trash bags on this blog post by AAA Polymer.
Starting with Plastic
In today’s manufacturing process, plastic can liners start out as small, cylindrical pellets of polyethylene resin. This flexible plastic is resistant to chemicals and moisture, and it has good insulating properties.
2 Main Types of Polyethylene Used to Make Can Liners:
- Linear Low Density Polyethylene (LLDPE) is the most common type of can liner, thanks to its ability to withstand quite a bit of puncture damage and greater impact. Got trash with sharp points? Use LLDPE bags!
- High Density Polyethylene (HDPE) is used in garbage bags that need to hold heavy or wet trash, but not sharp objects, because despite being very strong (it’s used in grocery store bags!), it is pretty easily punctured. Most HDPE trash bags are used for bathrooms, lightweight trash, and paper.
The Manufacturing Process
As you might guess, technology and machines handle a majority of the process of turning small plastic pellets into large, thin trash bags.
- The pellets are poured into large hoppers, which feeds them into an extruder.
- The extruder melts and mixes the pellets at high temperatures, resulting in a molten plastic mixture.
- The mixture is forced through a die, which cuts and shapes it by creating a ring, then blowing air into it to form a bubble.
- Rollers will collapse the bubble into a flat tube, and it is sliced into manageable pieces.
- Finally, each pieces is sealed with heat on one side, and they are measured and perforated before being rolled and packaged.
Here’s a video showing the process:
It’s a simple yet scientific process to create the trash bags we may sometimes take for granted! You can shop a large selection of trash bags and can liners at perryop.com!
