frost line

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Related to frost lines: Freezing depth

frost line

[′frȯst ‚līn]
(geology)
The maximum depth of frozen ground during the winter.
The lower limit of the permafrost.
(materials)
In polyethylene film extrusion, a ring-shaped area with a frosty appearance at the point where the film reaches its final diameter.

frost line

An imaginary line indicating the depth of frost penetration in the ground.
References in periodicals archive ?
This was not the case, and the films that initially gave the highest haze values, those produced with high frost lines, also gave the highest values after coating with the oil.
Samples produced by varying both the frost line height and the extrusion temperature were studied in order to determine which processing conditions produce films with the most desirable optical properties.
The draw rate was kept constant for all the samples, while the extrusion temperature and frost line height were varied.