How is saran wrap manufactured? What are the raw materials that make the plastic, and then how do they get it onto a spool so neatly? Lastly, what makes it “sticky?”
In a factory.
Google. “Saran wrap composition”. You tell me.
It’s extruded and rolled up onto a cardboard core as it comes out of the extruders.
Static electricity is what makes it cling.
Saran film is ‘blown’, much like a bubble gum bubble, but ring-shaped extruder nozzles keep feeding the bubble with more raw material all the time. A system of rollers and take-up reels collect the now cool tube of Saran high up in the factory. It’s later unrolled and slit into sheets.
Saran is Polyvinylidene Chloride.
Why is anything ‘sticky’? Aren’t chemists still working on this seemingly basic question?
Some interesting trivia: Saran was not originally used for food. It was sprayed on fighter planes in World War 2! It protected the planes from salty sea spray.
Here is some info about it’s discovery and uses:
I have also heard that Saran film was used to wrap guns during WWII, to protect them from moisture.