FLEXIBLE PACKAGING:
SMALL GLOSSARY

1Adhesive lamination
A type of lamination where adhesive is used to bond films together.
2BLEED
The area where ink extends into the slit area to provide a clean edge on a finished impression.
3coefficient of friction (Cof)
A measurement of how slippery a film is.
4BLOWN FILMS
Plastic films are produced from synthetic resins (such as polyethylene) using a process where molten resin is extruded through a circular die into a tube. This tube is expanded (“blown”) by internal air pressure into a larger bubble with a reduced wall thickness and then cooled with external air quenching.
5Seal bond
The strength of a seal measured in grams on a tensile tester.
6Lamination bond
The strength of the bond between two or more films measured in grams on a tensile tester.
7Horizontal form/fill/seal (HFFS)
A type of packaging line most commonly used for solid products, in which flexible packaging rollstock is formed, filled with product, and sealed.
8Extrusion lamination
A type of lamination where a curtain of molten polyethylene (PE) is used to bond films together.
9Print layer
The outer layer of a flexible packaging structure to which ink is applied to
10Fin seal
A type of seal where the inside layer is sealed to itself
11Nylon film
A material commonly used in flexible packaging structures to add strength and puncture resistance.
12Core
A cylinder around which packaging film is wound
13Plate
A substrate that transfers ink onto the flexible packaging film.
14Polyester (PET) films
A stiff, heat-resistant material with good clarity commonly used in flexible packaging. It doesn’t stretch and is ideal for flexographic printing. PET can be metalized, matte, or clear.
15Polyethylene (PE) films
Films are commonly used in flexible packaging, with a variety of blends available that provide different properties. For example, high-density PE (HDPE) provides stiffness. Low-density PE (LDPE) provides puncture and tear resistance. Ethylene Vinyl Alcohol (EVOH) can be used to add a barrier. The metallocene can be added for clarity, stiffness, and strength. PE films can be white or clear.
16Oriented polypropylene (OPP) films
A multilayer material commonly used in flexible packaging with advanced seal properties and barrier properties. Non-cavitated films typically have a gauge of .5 to 1.2 mils. OPP can be metalized, matte, clear, or white.
17Reverse print
Printing on the inside of the outer layer of a flexible packaging structure prior to lamination. This protects the printing from scuffing and prevents the need for an overprint varnish.
18Structure
The total combination of films that make up the finished flexible packaging film construction.
19Gauge
The thickness of a film or flexible packaging structure (typically expressed in mils).
20Die line
The layout or blueprint used for creating flexible packaging film or premade pouch graphics.
21Eye mark
A printed mark used to control repeat registration.
22Lap seal
A type of seal where the inside layer is sealed to the outside layer
23Number across
The number of lanes of impressions being printed at one time.
24Repeat
How long an impression is in the machine direction
25Rollstock
Flexible packaging film in roll form
26Sealant layer
Typically the innermost layer of a flexible packaging structure, with sealing properties.
27Vertical form/fill/seal (VFFS)
A type of packaging line most used for granular or loose products, in which overhead scales drop the product into a package as it is formed and subsequently sealed.