Definition
A lightweight cellular material made by introducing gas bubbles into a plastic resin during manufacture, producing a rigid or flexible structure of trapped air pockets within a plastic matrix. Used in aircraft for thermal and acoustic insulation, lightweight cores in sandwich panels, cushioning in seats and interiors, and as a tooling or filler material.
Plain English
Plastic that has been puffed up with tiny gas bubbles to make it light and full of air, like a stiff sponge. It can be soft and squishy or hard and rigid depending on the type.
Context Anchor
Seen in aircraft materials, cabin interiors, seat cushions, insulation, and some maintenance or repair discussions.
Derivation
‘Foamed’ comes from the same root as foam — froth full of bubbles. ‘Plastic’ comes from the Greek plastikos, meaning ‘able to be molded.’ Together: a moldable material that has been turned into a bubble-filled solid.
Why Pilots Care
Foamed plastic cores make modern aircraft structures strong without adding much weight. Knowing what it is helps when reading maintenance manuals, inspecting interiors, or understanding why certain panels feel light but stiff.
Intuition Check
Foamed plastic does not mean any soft packing foam is acceptable in an aircraft. In aviation, the exact material matters, especially for strength, fire safety, and where it is installed.
Example Sentence 1
The cabin sidewall panels use a foamed plastic core sandwiched between two thin fiberglass skins to keep the structure light.
Example Sentence 2
Foamed plastic seat cushions must meet strict flammability standards for passenger safety.