Knowledge Center
Glossary
Short definitions of the terms used across the stretch film industry. 28 terms.
- Blown film
Stretch film made by inflating the melt into an air-cooled bubble. It is tougher and more puncture-resistant, but hazier and louder than cast film.
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- Cast film
Stretch film made by casting the melt onto a chilled roll. It is clear, quiet when unwound and very even in thickness.
Read more- Cling
The film's ability to stick to itself, so the wrapped layers hold together without tape or glue.
Read more- Core
The tube a film roll is wound on, usually made of paper; 38, 50 and 76 mm are the common inner diameters. Cores are bought ready-cut to the roll width; rewinding machines do not cut them.
- Coreless film
Stretch film wound without a paper core, so the whole roll is usable film and no core waste is left behind.
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- Declaration of compliance
A written statement from the supplier that a food-contact plastic meets the applicable rules (EU Regulation 10/2011; in Türkiye, Communiqué No 2019/44), with its conditions of use.
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- Extrusion
The production process in which plastic pellets are melted in an extruder and pushed through a die to form film.
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- Folded edge
A film edge folded over during rewinding, giving the roll a reinforced edge that resists tearing, especially valuable on pre-stretched film. It is used on full-width rolls, not together with slitting.
Read more- Fully automatic rewinder
A rewinding machine that cuts the film, changes the core and ejects the finished roll by itself, without stopping the line.
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- Gauge
A North American unit of film thickness: 100 gauge = 1 mil = 25.4 µm, so 80 gauge is about 20 µm.
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- Hand stretch film
Stretch film in small, light rolls applied by hand, typically about 50 cm wide, 2–3 kg and around 200–300 m long.
Read more- Holding force
The force with which wrapped film presses a load together and onto its pallet (also called containment force). It grows with the stretch and the number of wraps, and declines over time after wrapping.
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- Jumbo roll
The large master roll that comes off the film production line, later rewound into smaller rolls ready for sale.
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- LLDPE
Linear low-density polyethylene, the main raw material of stretch film. It gives the film its stretch, toughness and puncture resistance.
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- Pre-stretched film
Film that has already been stretched during rewinding, so it is thinner and covers more of a load per metre with less effort.
Read more- PVC cling film
A thin, clear, plasticised polyvinyl chloride film with natural cling, used mainly to wrap food. As a food-contact material it must meet food-contact legislation.
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- Recycling code
The number that identifies a packaging plastic for sorting. Under EU Decision 97/129/EC, 3 is PVC and 4 is LDPE, the group stretch film belongs to.
Read more- Rewinding
Unwinding a jumbo roll and winding the film again onto smaller rolls in the required length, weight and core size.
Read more- Rewinding machine
A machine that turns jumbo rolls into sellable stretch film rolls; some models also slit, pre-stretch or wind without a core.
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- Semi-automatic rewinder
A rewinding machine that winds rolls automatically but needs an operator at every roll change to cut the film, remove the roll and fit a new core.
Read more- Servo tension control
Driving the unwind and rewind with separate servo motors so film tension can be set precisely, which is useful for jumbo rolls with varying cling.
Read more- Slit stretch film
Stretch film cut lengthwise into narrow rolls on a slitting rewinder; used for bundling profiles, cables, hoses and small items.
Read more- Slitting
Cutting film into narrower, equal widths during rewinding: for example, one 50 cm jumbo roll into two 25 cm rolls. On Öncümak machines, slitting is an option on the SM-1300 series (2 to 10 rolls) and on the CR-1700 (2 coreless rolls).
Read more- Static charger
A unit on a rewinding machine that charges the film electrostatically so it grips the empty core quickly at each roll change.
Read more- Stretch film
A thin, elastic plastic film, usually LLDPE, that is stretched around goods and holds them together through its recovery force and cling.
Read more- Stretch wrapping machine
A machine that wraps pallets with stretch film (also called a pallet wrapper). It uses film rolls; it does not produce them.
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