IMPAK CORPORATION

MIL-PRF-131K Grade 500m

MIL-PRF-131K Grade 500m is a heavy duty, foil-based, moisture barrier laminate designed for a wide variety of applications. It is designed to minimize contamination from source including outgassing and non-volatile residues in addition to being waterproof, greaseproof, flexible and heat sealable. With excellent puncture and tear resistance, it is well suited for packaging items large or small that require protection from the elements. Grade 500M is an economical solution required military packaging situations.

This moisture barrier film is on the QPL for MIL-PRF-131K and is converted in accordance with MIL-DTL-117H.

Features:

QPL listed as of April 5th, 2017
Superior chemical resistance.
Excellent puncture and tear resistance.
Ultimate heavy duty barrier packaging
Linear low density Polyethylene inner sealant layer for easy sealability.
Low MVTR. Protects against damage caused by humidity, moisture, oxygen, odors, and other airborne contaminants.
Lightweight and puncture resistant.
Conforms to the shape of products during vacuum packaging easily.
Suitable for vacuum packaging applications requiring nitrogen flushing.
Class 100 clean room production.
Date and lot coded for traceability.
Thermal transfer identification print is standard.
Available in zipper, side and bottom gusset configurations
Lead-free RpHS 2, REACH and Conflict Mineral compliant

Specifications

Physical Properties	Test Method	US Std.
Thickness - Average	ASTM D374	5.4 mil.
Yield		5094in²/lb
Tensile Strength MD - Average TD - Average	ASTM D882	5366 psi 7251 psi
Graves Tear MD - Average TD - Average	ASTM D1004	3 lbs. 3.5 lbs.
Spencer Impact - Average	ASTM D3420	13.0 lbs.
Puncture Resistance	FTMS 101C Method 2065	18.0 lbs.
Moisture Vapor Transmission Rate	ASTM F1249 (37.8°C, 90% RH)	0.0005 g/100in²/day
Oxygen Gas Transmission Rate	ASTM F1249 (23.0°C, 0% RH)	0.0005 g/100in²/day
Heat Seal Range	ASTM F88	275°F - 500°F
Seal Strength - Minimum (200°C, 1s, 4 bar)	ASTM F88	>14.0 lbs

IMPAK CORPORATION makes no warranty, expressed or implied, as to the suitability of these materials for any specific use. The values shown above were developed from random samples taken from production material. We believe them to be typical for the product. Actual values may vary somewhat from those depicted here. Customers should determine product suitability based upon their own internal criteria.

Last Revised 2026