Index open-cell foam Foamed or cellular material with cells that are generally interconnected. Closed cell refers to cells that are not interconnected. Index organic Matter originating in plant or animal life or composed of chemicals of hydrocarbon origin, either natural or synthetic. The alignment of the crystalline structure in polymeric materials in order to produce a highly aligned structure. Orientation can be accomplished by cold drawing or stretching in fabrication.
Oriented materials are anisotropic.
Orientation can generally be divided into two classes, uniaxial and biaxial. Index orthotropic Having three mutually perpendicular planes of elastic symmetry. The time a prepreg is exposed to ambient temperature, namely, the total amount of time the prepreg is out of the freezer. The primary effects of out time are to decrease the drape and tack of the prepreg while also allowing it to absorb moisture from the air. Index ovaloid A surface of revolution symmetrical about the polar axis that forms the end closure for a filament-wound cylinder.