Co-Polymers
Co-polymers (such as polyethylene/polypropylene) result when two monomers are combined during polymerization and are composed of repeating monomers and are actually homo-polymers.
EVOH
Ethylene vinyl alcohol (EVOH) resins are hydrolyzed copolymers of vinyl acetate and ethylene. EVOH has excellent gas, aroma, and solvent-barrier properties.
Laminate
A general term used to describe packaging structures composed of two or more materials, each designed to contribute one or more desirable properties to the final construction. There are many techniques for producing laminate materials, i.e., extrusion, adhesive laminating or extrusion coating. Syn. Composite.
Polymer
A gas heated under pressure goes from a gas to a solid. This is called "polymerization". The resultant material is called polymer. A polymer is a chain-like compound of high molecular weight formed by linking together of simple molecules under suitable conditions.
Saran (Polyvinylidene Chloride)
Saran films are made from co-polymer that is predominately vinylidene chloride (PVDC). Due to the very high chlorine content of the polymer, unplasticized saran film is highly crystalline and has high barrier to passage of oxygen and other gases, water vapor, odors, aromas, and flavors.
Area Yield
Area of material per pound of weight expressed as square inches per pound. The lower the specific gravity of film, the greater its "yield" per pound of material. The heavier the gauge,
the less the yield per pound of material.
Specific Gravity (Density)
The ratio of the weight of a volume of material to an equal volume of water at a specific temperature.
MSI
1000 square inches.
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