Turntable stretch wrappers are a type of ''automatic'' and ''semi-automatic''
stretch wrap
Stretch wrap or stretch film is a highly stretchable plastic film that is wrapped around items. The elastic recovery keeps the items tightly bound. In contrast, shrink wrap is applied loosely around an item and shrinks tightly with heat. While ...
ping system. A load is placed on a
turntable
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
, which rotates relative to the
film roll, which is housed in a carriage attached to a vertical "mast" on which it may move up and down.
Information
In the simplest turntable systems, stretch is achieved by rotating the load at a speed in which the take-up demand on the load surface is faster than the rate at which the film is allowed to be fed, being limited by a brake system.
More sophisticated systems also ''pre-stretch''
Crawford-Provincial: Stretch Wrap Terms
/ref> the film before wrapping by means of fixed/variable gear ratio
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage.
Gear teeth are designed to ensure the Pitch circle diameter (gears), pitch circles of engaging gears roll on each other without slipping, pr ...
s or other, even more sophisticated means, such as hydraulic ratios which can better take advantage of film "sweet spots", improving performance and film savings.
References
External links
Gloss Metallic Car Vinyl WrapFilling, Packing & Packaging Machine
* "Encyclopedia of Packaging Technology" {{ISBN, 978-0-470-08704-6
Packaging machinery