Mylar Bag will insure your food will be available when you need it. Made of a 4mil multi layer poly and aluminum foil laminated together. Mylar bags are used for long term food storage because the metal barrier protects food from moisture, light and oxygen. Air cannot get in or out of a properly sealed mylar bag. Mylar bags are popular due to their good puncture structure, outstanding barrier, and relatively low cost characteristics. Our mylar bags are constructed from silver laminated PET/Foil/Poly barrier film. This barrier film has an OTR of only .0006 cc/100sq. in./24hrs. from the standard Mocon test method.
PET/Foil/Poly is a cost-effective foil barrier material used where excellent oxygen and moisture levels are required. It is FDA approved, has a shiny silver appearance and is used extensively in food, medical, and general industry. It is a popular structure due to its good puncture, outstanding barrier, and relatively low cost characteristics.
Metalized vs. Foil:
Some people call all silver film they see “foil”. This is a misconception that leads to misapplication.
Many silver films are indeed foil, but some are actually metalized. Metallized material is comprised of
aluminum dust vacuumed to a substrate such as Polyester or Polypropylene. A foil film is comprised
of an actual solid aluminum foil layer (not dust). Metallized film is less expensive than foil film, but the
foil film has a much better oxygen and moisture barrier properties.
How can I tell the Difference?
Foil: Foil structures have a shinny and a dull side. Look at the inside of the pouch and compare it to
the exterior of the pouch. If they look different (shinny vs. dull), it is a good chance that the structure
Metallized: The interior and exterior of the film or pouch are both shinny. If you hold up the film to a
light, many times you can see through the film. This is because you are seeing though the aluminum
dust particles as it is not completely opaque.
PROPERTIES TEST METHOD UNIT OF MEASURE TYPICAL VALUE
Caliper mils 4.0
Yield sq.In/Lb 6371
MVTR Mocon gms/100 sq. in./24 hrs .0006
OTR Mocon cc/100 sq. in./24 hrs .0006
Burst Mullen psi 58
Tensile MD ASTM D-882 lbs. at break 21
Tensile XMD ASTM D-882 lbs. at break 22
Tear MD ASTM 689 lbs. at break 96
Tear XMD ASTM 689 lbs. at break 96
Puncture Fed. TM 2065 Lbs. 13
*The values indicated in this document are the results of tests made in compliance with the normal standards. They are given as an indication and
should be considered as average values and given without any obligation on our part. This data was provided directly from our film supplier.
What is OTR?
OTR (oxygen transmission rate) is the steady state rate at which oxygen gas permeates through a film at specified conditions of temperature and relative humidity. Value are expressed in cc/100 in2/24 hr in US standard units and cc/m2/24 hr in metric (or SI) units. Standard test conditions are 73°F (23°C) and 0% RH.
Relevance to Package Performance:
The air we breathe is about 21% oxygen and 79% nitrogen, with very small concentrations of other gases like carbon dioxide and argon. Essential to human and animal life, oxygen gas is also a reactive compound that is a key player in food spoilage. Most of the chemical and biological reactions that create rancid oils, molds, and flavor changes require oxygen in order to occur. So, it is not surprising that food packaging (and some non-food packaging for products where atmospheric oxygen causes harm) has progressed and found ways to reduce oxygen exposure and extend the shelf life of oxygen-sensitive products.
There are three methods for reducing product exposure to oxygen via flexible packaging.
MAP (modified atmosphere packaging) is a process for replacing the air in the headspace of a package with another gas before the final seal is made. This is also called gas flushing. The most common replacement gases are nitrogen or nitrogen/carbon dioxide mixtures. The shelf lives of potato chips, dried fruits, nuts, and shredded cheese are commonly extended by this packaging method.
Vacuum packaging is where the atmosphere is drawn out and eliminated, rather than being replaced by another gas. This vacuum forces the flexible material to conform to the product shape. Meats (fresh and processed) and cheeses are commonly packaged this way.
Inclusion of an Oxygen Absorber. An oxygen absorber placed in a properly sealed bag will absorb apx 21% of the air from inside the bag. The absorbed air is all the oxygen, leaving the nitrogen and trace gases left in the bag. Void of oxygen (and light) nothing like mold, fungus & insects can survive and grow to spoil the food or contents inside the bag.
Once air has been replaced or eliminated from the package, there must be an adequate oxygen barrier and seal integrity to keep a low oxygen
concentration inside the pack. Otherwise, the driving force created by the oxygen partial pressure differences (21% outside the bag and 0-2%
inside the bag) will cause an ingress of oxygen and destroy the benefit of removing it in the first place. OTR values are used to compare the
relative oxygen barrier capabilities of packaging films. An industry rule-of-thumb is that a material is considered a "high oxygen barrier" if its OTR
is less than 1 cc/100 in2/24 hr (15.5 cc/m2/24 hr).
In order for film oxygen barrier to contribute its full product protection value, package seal integrity must be satisfactory. Poor quality seals can negate a film's good barrier by allowing oxygen transmission through channel leaks and imperfections.
What Affects the OTR of Films:
Good oxygen barrier is achieved by combining functional layers to create a film with the required barrier, as well as those other properties necessary to produce a serviceable package. OTR is most affected by the following factors;
Thickness of barrier layer: Generally, the thicker the oxygen barrier-providing layer, the better the barrier. But there are process and cost limitations that restrict the thicknesses that can be realistically produced or successfully utilized.
Base film surface compatibility: The physical and chemical characteristics of the base film surface have a major effect on the OTR after metallization, and to a lesser degree, after coating.