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The most commonly produced plastic consumer products include packaging made from LDPE (e.g. bags, containers, food packaging film), containers made from HDPE (e.g. milk bottles, shampoo bottles, ice cream tubs), and PET (e.g. bottles for water and other drinks). Together these products account for around 36% of plastics use in the world.
This applies to open cell foams where the bending moment is exerted on the cell walls. The foams can be made of any material with a plastic yield point which includes rigid polymers and metals. This method of modeling the foam as beams is only valid if the ratio of the density of the foam to the density of the matter is less than 0.3.
The thicker barriers of transparent plastic used in teller's windows and barriers in banks are also polycarbonate. So-called "theft-proof" large plastic packaging for smaller items, which cannot be opened by hand, is typically made from polycarbonate. Lockheed Martin F-22 cockpit canopy
Plastic’s versatility, durability, and low weight-to-strength ratio have made it an efficient material for many of life’s modern conveniences. However, by their nature, plastics can break down ...
Polystyrene (PS) / ˌ p ɒ l i ˈ s t aɪ r iː n / is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. [5] Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to air and water vapor and has a relatively low ...
HDPE is known for its high strength-to-density ratio. [4] The density of HDPE ranges from 930 to 970 kg/m 3. [5] Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. [6]
POM is a strong and hard plastic, about as strong as plastics can be, and therefore competes with e.g. epoxy resins and polycarbonates. The price of POM is about the same as that of epoxy. There are two main differences between POM and epoxy resins: epoxy is a two-component resin that can be cast, and adheres to everything it touches,
A combustion engine's spark distributor rotor made of Bakelite. Molded Bakelite forms in a condensation reaction of phenol and formaldehyde, with wood flour or asbestos fiber as a filler, under high pressure and heat in a time frame of a few minutes of curing. The result is a hard plastic material. [27]