Glossary
Banding
Applying multiple wraps of stretch film to reinforce a specific area of a pallet or to band together multiple units.
Product example: banding stretch film
Blown Film
Stretch films manufactured by the blown film extrusion process are called blown films. Stretch film extruded by the blown method typically produces greater puncture resistance but less aesthetic values than cast films.
Product example: blown hand stretch film
See also: stretch film standard specifications and stretch film calculator
Bottom Wraps
The rotations a stretch wrap machine makes applying stretch film to the lower portion of a unitized load. Bottom wraps of more than one rotation augment pallet stability.
See also: packaging equipment distributor
Cast Film
Stretch films manufactured by the cast film extrusion process are called cast films. Stretch film extruded by the cast method typically have greater tear resistance, greater aesthetic values and are quiet to unwind, which is not typically found in film manufactured by the blown method.
Product examples: machine cast stretch film, hand cast stretch films
See also: stretch film types
Cling
Cling provides the sticking to self but not to the product attribute. Films will be designed as a single side cling or a two sided cling. The cling bonding agent is typically added in as a single side or two sided layer in the co-extrusion process.
Co-extrusion The process of taking materials that are; fed, melted and or pumped in through other extruders, which are then merged to create a multi-layer film.
See also: stretch film types
Dart Drop
A technique used to measure the impact strength or sturdiness of a film; this is ascertained by dropping a crescent shaped weight (aka dart) onto a film.
Elastic Recovery When the stretch film is stretched, strained and / or deformed its ability to recover and return to its original form indicates its elastic recovery capacity.
Elmendorf Tear A testing means for measuring a materials ability to resist tearing forces. This method initiates a tear in a sample material, then measure to the amount of force needed to tear the sample apart. Test result value is referred to as the tear value.
Extruder
A piece of equipment hat uses mechanical and thermal actions to change solid polymer into a molten polymer.
Extrusion A manufacturing process that takes materials from one or more extruders, the resulting extradates are then configured to the fabrication of the end product.
Film Feed The speed at which the film is supplied to the load is the film feed. Film feed rate adjusts as needed on load corners to maintain consistent film tension.
Film Force
As the film is applied the rate of tension in the film is called the film force or film tension. The rate is usually measured in pounds.
Film Memory Is the memory of the stretch film trying to return to its original un-stretched form and in the process makes the load tighter and more consistently secure. This prevents loosening of the load that can occur later as the load settles. To achieve optimal film memory and film efficiency, proper film and application settings are essential.
Film Tail
The film tail refers to the start and end pieces of stretch film that are initially applied and then later cut off from a pallet in the stretch wrapping process.
Gauge
An imperial measurement used to measure stretch film thickness or caliper. An example value would read as: 70 gauge, 80 gauge or 100 gauge. Also note: Often used as a synonym for film thickness.
See also: stretch film conversion calculator
Gloss
Refers to a surfaces shine or sparkle, in LDPE stretch films it refers to the amount of light that is reflected from the stretch films surface. High gloss attributes are typically found in cast stretch films.
Product example: machine cast stretch film and hand cast stretch film
Hand Film
Hand stretch film used for manual stretch wrap packaging application. Designed for hand wrapping application, hand film rolls are lighter and smaller than machine film rolls to make application easier. Also known as hand wrap, hand stretch wrap and hand stretch film.
Product example: hand stretch film
Haze
Refers to lack of clarity and inability to see through a film, it is measured by the percentage of light not transmitted through a film sample. Characteristic is typical of blown stretch films.
Product examples: blown stretch film and hand blown stretch film
Impact Strength
The capability of a stretch film or other material to defy rapidly applied destructive forces.
LDPE Stretch Film
Low Density Polyethylene Stretch Film
Product examples: stretch films
See also encyclopedia definitions: low density polyethylene
LLDPE Stretch Film
Linear Low Density Polyethylene Stretch Film
Product examples: stretch films
See also encyclopedia definitions: linear low density polyethylene
Machine Direction
Refers to the direction perpendicular to the film width. Acronym: MD.
Machine Films Also referred to as Machine films, is stretch film designed for stretch film equipment.
Product examples: machine stretch films
Metallocene
New polyethylene resins developed using Metallocene change the polytheylene chain structures resulting in a new breed of stretch films. Metallocene stretch films can achieve increased puncture resistance and clarity while blends offer balanced film properties and universal stretch percentage applications (ex: machine film, hand film).
Product examples: machine stretch films and hand stretch films
Microns
Microns is a metric measurement used for measuring film thickness. One micron is equal to one millionth of a metre or a thouandth of a millimetre.
See also: microns to gauge conversion calculator or standard stretch film sizes, weights and gauges
Neckdown
Neckdown is when a film losses its dispensing roll width / breadth and narrows down while being stretched. Neckdown reduces coverage each wrap provides thereby making it likely that more wrap rotations and more film will be needed to wrap a load or pallet.
Overwrap
Refers to the amount of stretch film applied over the top of load. Overwrap provides a downward force on a pallet load and is often used to secure a pallet top sheet or corrugated top cap in place.
Pallet Covers Poly film covers commonly used to protect pallets from dirt, dust and/or conceal pallet contents.
Product examples: palletising products, pallet covers and sheeting film
Poststretch
Poststretching is stretching a film by using the load to pull the film out at the same time as it applies film. Although this allows for the benefit of film tension, the tension levels are inconsistent and as such can damage many load types. Attempts to attain higher tension stretch can be done but can increase risk of damaging some load types and increase chances of stretch film breakage.
Prestretch
Prestretching is stretching the film prior to application. The process can increases film strength, improve load integrity, reduce amount of stretch wrap film needed and save on stretch film packaging costs. Today many stretch films are designed to achieve optimal prestretching values that can be attained with leading edge high performance stretch wrap machines as well as prestretched films for manual application operations.
Product examples: machine stretch films and hand stretch films
See also: stretch film types and buy, lease or rent stretch wrap machinery
Roping
Bunching the stretch films full width to create a rope is known as roping. Stretch film roping is extremely strong and is often used to further secure a pallet to its load. Bunching stretch film is a feature function of many stretch wrap machines (ex: turntable stretch wrappers).
See also: buy, lease or rent stretch wrap machinery
Tackifiers
Additives used in the material fabrication process to increase the tack of the film or material. See also: cling
Tear Resistance
Refers to the resistance of the film to tear. Attribute is quantified by measuring the force needed to propagate an initiated tear.
Tensile Strength Tensile strength a measurement of the maximum amount of force a material can take without breaking. The greater the tensile stretch measurement, the stronger the material.
See also encyclopeda definitions: tensile strength
Tension Stretch
Tension stretch is a pulling force that stretches materials. For example: stretching a rubber band will make it longer, as it gets longer its tension increases. Also referred to as poststretch
See also: poststretch
Transverse Direction
Refers to the direction across the stretch film web. Also referred to as TD.
Wide Web
A specialty sized large film roll designed for equipment that wrap using larger widths.
Product example: wide web pallet wrap
Yield Strength
The amount of stress a material can withstand without permanently having plastic deformation. Prior to reaching the yeild point a material will elastically deform but will return to original shape once the stress is removed.
See also encyclopeda definitions: yield strength
Zippering
Refers to the lack of resistance to of an initiated TD tear or cut. Once initiated, the tear will rapidly spread.