The support format changes the whole sleeve-sealing process
A tray, flat pad or trayless collation influences how products are grouped, pushed through the film, supported in the tunnel and handled after cooling. The best route depends on container geometry, base stability, bundle weight, row pattern, distribution handling and the amount of exposed product that is acceptable.
| Format | Potential advantages | Points requiring trial evidence |
|---|---|---|
| Tray-supported | Provides a defined base and side support; can make irregular or heavier collations easier to transfer and lift. | Tray rigidity, corner shape, product overhang, film snagging, heat response and material use. |
| Pad-supported | Provides base support with less side structure and may support printing or pallet handling requirements. | Pad stiffness, position during collation, edge exposure, product retention and movement on conveyor transfers. |
| Trayless | Reduces support material and can create a compact bundle where products are naturally stable. | Collation control, product friction, row stability, side opening, lifting method and recovery after stops. |
Assess stability before and after shrinking
Before the tunnel, the group must remain square while it crosses guides, film and transfer gaps. Tall, narrow or low-friction products may need more positive collation than short, broad containers. A tray can improve stability, but a poorly sized tray can also introduce sharp corners, product overhang or trapped film.
After the tunnel, the film and support work together. A tray or pad carries some load; a trayless pack relies more heavily on the film and the geometry of the containers. Check the bundle after full cooling and repeat the intended lift, turn, accumulation and pallet placement. Do not assume a pack that survives a short hand lift will remain stable through automated transfer or distribution.
Material decisions need a complete-pack view
Removing a tray or reducing film may lower material use, but the decision should also consider product loss, rework, transport damage, line stops and whether a stronger film or more complex collation becomes necessary. Compare complete pack options with representative trials and the organisation's packaging requirements. Lancing can help establish the machinery and trial route; final packaging-material compliance and environmental decisions remain with the packer and its material advisers.