Stretch Wrapper Product

Overview

A turntable stretch wrapper applies layers of pre-stretched plastic film around a pallet, securing the load during storage and transport. Unlike pallet strapping (which uses narrow strap), stretch wrapping uses wide, thin plastic film (typically LLDPE) that conforms to the load shape. The film is pre-stretched (stretched to 150–300% of its original length) before application, which improves containment while reducing material usage.

Turntable wrappers are the most widely deployed pallet wrapping machines in distribution centres, warehouses, and manufacturing facilities. They combine simplicity, reliability, and cost-effectiveness.

How it works

Pallets arrive on the Infeed Conveyor, driven by the Infeed Motor. The Infeed Sensor detects pallet position, and it is indexed onto the Rotating Turntable.

The Rotating Turntable is a rotating platform driven by the Table Motor via a Helical Gear Pair. The pallet sits on the Table Deck, supported by a large journal Table Bearing. The Pallet Sensor confirms the pallet is in position before wrapping begins.

The Film Unwind Station supplies film from a large roll held on the Film Spindle. The Film Brake maintains constant feed tension. Film is guided by the Film Guides and flows to the Prestretch Unit.

The Prestretch Unit stretches the film before it reaches the pallet. The Prestretch Wheels (a pair of pinch rollers) run at different speeds, controlled by the Prestretch Motor. Pre-stretching reduces film consumption by 30–50% while improving load containment. The Prestretch Sensor monitors the actual stretch percentage.

The film then passes to the Film Carriage Assembly, a complex assembly mounted on the Mast Assembly. The carriage is driven by two servo axes:

• The Carriage Z Servo (vertical) raises and lowers the Film Applicator Head from the bottom to the top of the pallet.
• The Carriage Y Servo (radial) moves the film head in and out, positioning it at the correct distance from the rotating load.

As the Rotating Turntable rotates (typically 10–20 rpm), the Film Applicator Head moves vertically and radially, spiralling the film around the pallet. The Film Guide Wheel ensures film trajectory is smooth, and the Film Tension Sensor monitors applied tension to prevent film breakage or loose wrapping.

The number of film layers and wrap pattern (spiral, cross-wrap, or combination) is controlled by the Control System via the Control Cabinet PLC. Typical wrapping sequences apply 2–8 spiral passes plus optional cross-wraps on the top and sides.

Once wrapping is complete, the film is severed (often via a hot-wire or mechanical blade, not shown) and the pallet is indexed off the turntable onto the Discharge Conveyor, driven by the Discharge Motor.

The HMI Panel allows operators to select wrapping profiles (light, standard, heavy) based on load fragility and stacking height. Recipes store the number of passes, prestretch ratio, carriage speed, and turntable speed. The Safety Module enforces the E-Stop Button and protective guards around the rotating turntable and moving mast.

Load stabilisation and efficiency

Pre-stretching is the key efficiency feature. By stretching film to 150–300%, each kilogram of film covers 1.5–3 times more area, reducing consumption from 5–10 kg/pallet (in unstretched systems) to 2–5 kg. The stretched film maintains its tensile strength during transport, securing loads effectively.

Spiral wrapping (carriage moving continuously from bottom to top) is fastest. Cross-wrap (additional horizontal passes around the top and sides) improves top-load stability and is used for fragile or high-stack applications.

Wrap weights (measured in grams of film per pallet) typically range from 1500–4000 g depending on pallet size, load height, and customer specifications. Modern machines achieve >99% wrap integrity and handle pallet speeds of 20–60 pallets per hour, making them ideal for high-volume distribution.