Definition
A manufacturing process in which heated, softened material — typically a thermoplastic resin — is forced under pressure into a closed mold cavity, where it cools and hardens into the finished shape of the cavity.
Plain English
A way of making parts by pushing melted plastic into a shaped mold and letting it cool until it sets into that shape.
Context Anchor
Seen in aircraft maintenance and parts descriptions for plastic interior pieces, housings, knobs, covers, and other molded components.
Derivation
From Latin 'injicere' meaning 'to throw in,' and 'mold' from Latin 'modulus' meaning 'a small measure or pattern.' Together the term describes throwing material into a pattern — which is exactly what the process does.
Why Pilots Care
Many small aircraft parts — cabin trim, ventilation outlets, switch housings — are injection molded. Knowing how they're made helps a pilot or owner understand why some plastic parts can't be repaired and must be replaced as a unit.
Intuition Check
Do not confuse injection molding with fuel injection. Here, “injection” means forcing material into a mold to make a part, not sending fuel into an engine.
Example Sentence 1
The instrument panel knobs were produced by injection molding, giving them a smooth, uniform finish.
Example Sentence 2
Technicians replaced the cracked injection-molded fairing with a new one from the parts bin.