Glossary of Packaging Terminology

Barrier Material
A flexible packaging material possessing properties that limit the transmission of various gases through the material. ( used to keep products dry, wet or extend shelf life and assure product freshness)
Barrier Packaging
The utilization of engineered materials that possess properties capable of preventing the permeation of harmful substances through material, which would result in product damage.
Biaxial Orientation
A film that has been stretched under certain temperature conditions equally in both the machine and transverse directions.
Blocking
A condition where a plastic film tends to stick to an adjacent surface, either film or some other substance.
Blown Film
Film produced by extruding resin into a tube, which is expanded by air pressure.
Bubble
The inflated tube of film in the blown film extrusion process.
Cast Film
Film extruded through a flat die into a quench system.
Center folded Film
Film folded in half in the machine direction and then wound into roll form.
Center folder
A device used to produce center folded film from flat film.
Clarity
Degree of transparency.
Coefficient of Friction (COF)
In plastics films, indicates the ease with which a film surface is slid against like film or adjacent surface. A low value (near zero) indicates a slippery; a high value (7 or more) indicates a tacky film, which will stick to itself.
Co-extruded Film
Flexible packaging material consisting of two or more different materials that are layered within a single ply during the extrusion process.
Collar Sealed
A style of heat seal where a molded fitment is sealed into the perimeter of a pouch or bag between the front and rear panels of the bag or pouch.
Copolymer
This is more than one plastic polymerized together at the same time.
Core
A paper tube used as a base for forming a roll of film. (PVC cores used for clean room applications)
Density
Weight per unit volume. Films with a low density offer more coverage per weight of film.
Desiccant
A substance used to absorb moisture. (typically placed inside enclosures to aid in the prevention of corrosion)
Elmendorf Tear Resistance
A measure of the resistance to tear after the film has been cut.
Elongation
The percentage a film will deform or stretch prior to breaking.
ESD: Electro Static Discharge
The release of potential electricity (or static); “sparking”
Export Packaging
Preparation of an item or product for overseas shipment (typically by ocean freight) through utilization of crating, cushioning and flexible packaging materials.
Extrusion
Technique for producing film. A mixture of resin and plasticizer is fed through a heated barrel where it is made plastic by heat and pressure by a continuously moving screw. The plastic mixture is forced out through a circular die, blown into a bubble, and then wound onto a roll at the end of the bubble.
Fitment
An injection molded “Spout or Valve” that is typically heat-sealed to a flexible packaging material.
FIBC: Flexible Intermediate Bulk Container
Woven polypropylene bulk bags.
Film
A general term for plastics having a thickness of 0.010 inches (10 mils) or less.
Fish Eye
An unrefined or unbelted mass in a transparent plastic film which has not blended completely into the surrounding material, giving somewhat the appearance of a fish eye. Also called gel.
Fogging
A buildup of water droplets on the surface of a film.
Gas Transmission Rate
(GTR) A measure of the permeability of a packaging film to gases. Expressed in cc/100sq. in./24 hrs./mil.
Gauge
Thickness of a plastic film(1/1000"=.001"=100 gauge)
Gaylord
A heavy duty corrugated carton of pallet load proportions.
Gloss
The amount of light reflected from a film at a given angle in ratio to the total light striking the sample. The more light a film reflects, the higher the gloss of the film.
Haze
The proportion of light which scatters in passing through a plastic film. Measured in percentage (the lower the percentage, the clearer the film), haze distorts colors and imparts a dusty, cloudy appearance to the film.
Heat Sealing
Joining plastic films by controlled application of heat and pressure to the area to be sealed.
Impact Resistance
The resistance to impact of a film.
Impulse Sealing
A heat sealing technique in which a pulse of electrical energy is applied to the sealing area for a very short time, followed immediately by cooling while material is held under pressure.
Initial Tear Resistance
A measure of the force needed to begin a tear in a film.
Irradiation
A process that uses high-energy electrons to cross-link or sterilize a film.
Laminated Structure (also Lamination)
A flexible packaging material comprised of two or more layers of separate materials that are attached by means of adhesive, solvents, or extrusion coating to form a single ply, multi-layer material designed to provide specific protective functions.
Lap Seal
A method of sealing plastic films where the two pieces to be sealed are overlapped, then heated to form a seal.
Low Temperature Flexibility
The lowest temperature at which a film can withstand a flexing test without cracking.
Machine Direction (MD)
The direction parallel to that taken by the majority of molecules in a plastic film, or the direction of the film web as it moves through the film-making machine. Also called Longitudinal Direction.
Migration
The Transmission of a material from within a plastic film to its surface or to another contacting material. Also called Bleed or Exudation.
Mil
Measure of the thickness of a plastic film. (.001" = 1 mil)
Modulus
A measure of film stiffness.
Mono Layer Film
Flexible packaging material consisting of a single ply of polymer.
Monomer
A comparatively simple organic compound which can under certain conditions, react to form a polymer.
Multi-ply Bag
A bag consisting of two or more plys of material that are not joined together. “A Bag-in a Bag”.
MVTR: Moisture Vapor Transmission Rate
A measurement of the amount of gaseous water that permeates through a material over a specific time and under specific conditions.
Orange Peel
A surface distortion of a plastic film which looks like the skin of an orange.
Orientation
Mechanical stretching of a plastic film to produce a parallel arrangement of its molecules. Films may be stretched uni-axially (in one direction, called preferential) or biaxially (in two directions).
OTR: Oxygen Transmission Rate
A measurement of the amount of Oxygen that permeates through a material over a specific time and under specific conditions.
Plastic
A synthetic resin which (a) generally has a high molecular weight;(b) is made up of at least two atoms;© is sold in its unprocessed and processed states but in between, while it is being processed into finished items, is softened enough through the combined application heat, pressure, and mechanical working to be formed into various shapes.
Plasticizer
A substance blended into a plastic to improve flexibility or softness.
Polyethylene
A resin made from ethylene gas which produces tough transparent film.
Polymer
A chain-like compound of high molecular weight formed by the linking together of simple molecules under suitable conditions. When two or more monomers are involved, the product is called a copolymer. (SEE MONOMER)
Polypropylene
A resin made from propylene gas which produces lightweight, highly transparent, stiff film.
Preservation Packaging
Preparation of an item or product for long term (usually 3 months or more) storage within an enclosure that will protect the item from spoilage or damage.
PVC – (POLYVINYL CHLORIDE)
A thermoplastic material composed of polymers of vinyl chloride; a colorless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalis. Compounded with plasticizers, PVC yields a flexible film, widely used in the manufacture of clothing and packaging films.
Resin
A solid or semi-solid organic material which has an indefinite and often high molecular weight; it exhibits a tendency to flow when subjected to stress and usually has a distinct softening or melting temperature range.
Sheet
A general term for plastic having a thickness of 0.010" or more.
Single Wound Film
Flat film wound on a core. (similar to paper towels)
3D Shroud
A three dimensional cover comprised of four side panels and an integral top panel (used for covering equipment, pallet loads & etc.).
VCI: Volatile Corrosive Gas Inhibitor
A substance utilized as a deterrent to corrosion.