Physical properties of Lexan

Density and relative density of Lexan films
The common usage of synonyms for these both terms is not correct: the density is the mass per volume unit of a material at 23°C. The relative density is the mass of a material volume in comparison to the same amount of water (both at 23°C). Exchange: density = relative density x 0.99756. These values are used to determine the area yield in m²/kg of films of a certain thickness.

Chart 3: Relative density

Formula for determining the area yield: 1/relative density x thickness (mm)

Water absorption and moisture content

To determine the affinity of a plastic to water absorption, a material sample with defined measurements is stored in water at a specific temperature for a certain time. Either the water absorption in mg or the weight increase in per cent is measured then. All films of GE Structured Products show low water absorption.

The moisture content in the material can affect the measurements of the applications and properties like electrical insulating, dissipation factor, mechanical strength and appearance (impression).