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Shrink Film Terminology

eLearning Guide Graphics 63 Common Shrink Wrap Terms

Do You Know the Shrink Film Terminology Used By Packaging Professionals?

  1. Angel hair: Thin strands of film appearing at the cut end of film resulting from the heat sealing.
  2. Ballooning: A pillow effect created when air is trapped within the shrinking bag and cannot escape.
  3. Bead Seal: A thin round weld created when pressure and heat are applied to two layers of film.
  4. Bi-Axial Orientation: Molecules Oriented along both X and Y-axis of the film web.
  5. Blocking: A condition in which two layers of like film adhere to one another.
  6. Blown Film: A film extruded by air inflation. Ex: blown stretch film such as: blown hand stretch film
  7. Burn Through: A temperature or condition where a film becomes cloudy or burns in the shrink tunnel.
  8. Centerfold Film: A film that has been folded in half, lengthwise.
  9. Centerfolder: A mechanical device used to create centerfolded film.
  10. Coextrusion: Two or more polymers extruded and combined in a die, each forming a distinct layer in the final film.
  11. Cold Sli: The amount of force required to slide two surfaces against one another at ambient temperature.
  12. Cold Flex (CF): Ability of a film to perform at low temperatures without failure.
  13. Copolymer: Result of two monomers being combined through polymerization.
  14. Core: A paper tube on which film is wound.
  15. Cross-Linking: A process which binds the polymer chains into a network. Significantly increasing a films heat stability and strength.
  16. Crow’s Feet : A series of wrinkles radiating out from a finished package’s corners.
  17. Dog-Ears: Triangular projections of unshrunk film at the corners of finished packages.
  18. Drape: The softness of a film characterized by the ability to conform to irregular shapes.
  19. Electron Beam: A device used in the cross-linking process.
  20. Fish Eyes: A scalloped surface on a finished product surface.
  21. Form-Fill-Seal: A type of shrink wrap equipment which produces a tube of film into which packages are introduced.
  22. Gauge: A term used to describe the thickness of a material such as shrink film / shrink wrap or stretch film / stretch wrap or pallet wrap ex: 100 gauge shrink film, 60 gauge stretch film, 70 gauge pallet wrap.
  23. Hole Punch: A mechanical device used to produce an air evacuation hole.
  24. Hot Slip: The amount of force required to side two surfaces of heated film against on another.
  25. Impulse Seal: A heat sealing technique where the element is pulsed with voltage during the sealing cycle.
  26. L-Sealer: A term used to describe equipment where the seal area is in the shape of a “L”.
  27. Laminate: A general term used to describe structures comprised of two or more materials.
  28. Lap Seal: A seal made with two layers of film overlapping one another.
  29. Machinability: The ability to form and seal on overwrapping equipment.
  30. Machine Direction (MD): The direction the film is manufactured and moves through the sealing equipment.
  31. Memory: The ability of a film to maintain its characteristics after shrinking.
  32. Monoaxial: A film which is oriented to shrink in only one direction.
  33. Monolayer Film: A single layer film extruded from one or a blend of raw materials.
  34. Mutilayer Film: A film comprised of more than one layer of similar or different polymers.
  35. Opaque: Relatively impervious to light. Ex: opaque white stretch film, opaque black stretch film (stretch wrap)
  36. Optics: The visual properties of a film. Examples of shrink film products with good optics include: Exlfilm HSP shrink film – a superior optic shrink film, Exlfilmplus LTF Shrink Film – shrink film has excellent optics & strength, LTG Shrink Film – a light gauge polyolefin shrink film with excellent clarity, gloss and tear resistance and Exlvalue Anti Fog Shrink Film (AF Shrink Film) – a anti fog shrink film providing clear presentation in refrigerator and freezer applications.
  37. Orientation: The stretching technique used in the manufacturing of film.
  38. Oriented: The stretching and aligning of a film’s molecules at a temperature below its melting point.
  39. Perforations: Air evacuation holes in a film made by pin perforators.
  40. Pin Perforators: A device used to produce small holes in film to allow air to escape during the shrinking process.
  41. Polyethylene: A simple thermoplastic polymer of ethylene.
  42. Polymer: A material made through the process of polymerization.
  43. Polymerization: A gas heated under pressure forms a solid.
  44. Polyolefin: A generic term used to describe ethylene and/or propylene based plastics. Also see polyolefin shrink film and shrink film packaging products
  45. Polypropylene: A thermoplastic polymer of propylene.
  46. Preferential Shrink: The characteristics of a film to shrink more or less in a specific direction.
  47. PVC: Polyvinyl Chloride. Also a type of shrink film.
  48. Seal Wire: An element made from nichrome wire used to seal film.
  49. Selvage: Another term for trim waste.
  50. Shrink: Defined as the ability to become smaller.
  51. Shrink Tunnel: A type of equipment featuring a chamber producing heat and airflow designed to shrink film.
  52. Singlewound Film (SW): A single layer of shrink film wrapped around a core.
  53. Slip: The quality of a film to move over surfaces with little resistance.
  54. Static: An electrical charge built-up in plastic film.
  55. Static Sea: A type of longitudinal seal used in FFS equipment. Overlapping film edges are adhered to one another via a static charge.
  56. Tap Switch: An electrical device used to control the amount of voltage introduced to sealing elements.
  57. Tear Initiation: The amount of force required to initiate a tear.
  58. Tear Resistance: The ability of a film to resist the propagation of a tear.
  59. Transverse Direction (TD): The direction parallel to the film width.
  60. Trim: The amount of excess film severed during the sealing process.
  61. Trim Seal: A seal made by using a sealing wire element.
  62. Unbalanced: Unequal orientation in the LD and TD.
  63. Wind: The direction in which the film or shrink film is wound on the core.

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