Ready to continue the various plastics? Today we are covering recycling number 4 which is LDPE, Low-density polyethylene. LDPE is like HDPE and MDPE as all three plastics are polyethylene. The biggest difference is that LDPE is not as strong or dense as HDPE and MDPE, but it does have the ability to handle more stretching forces without breaking.
LDPE is the original polymerization of the monomer ethylene. The first industrial synthesis of polyethylene was in 1933 by British company, Imperial Chemical Industries, and it was made by accident! However, the experiment was not easily replicated and it wasn’t until 1935 that a replicable method was discovered. This discovery became the basis for industrial production of LDPE in 1939. Due to the breakout of World War II, LDPE was deemed to be important for the construction and safety of the cables used in devices using Very High Frequency (VHF) electromagnetic radio waves. The use in military radios, radar sets, as well as other communication devices, meant the production process was a necessary secret. In 1944, two American companies began large commercial scale production of LDPE under license from Imperial Chemical Industries.
Where is LDPE used?
LDPE is used in plastic wrap, plastic coatings on wires, computer components, snap-on lids, six-pack rings for canned drinks and laboratory squeeze bottles. Like HDPE and MDPE, LDPE also has a lower cost which helps keep final product costs down.
Whew! I loved the history aspect about LDPE today. What did you think? Don’t miss out on tomorrow’s post on PP (Polypropylene)!