Tray Sealer

Short answer: A tray sealer heat-seals a lidding film onto pre-formed plastic, aluminium or paper trays, and can flush the tray with gas or vacuum-pack the product under a skin film. The configuration depends on the tray and film you use, the gas or vacuum requirement, and how much product or sauce is likely to reach the sealing flange.

How it works

Filled trays arrive on an infeed conveyor or are placed into the tool by hand. The trays move into the sealing station, where a lower tool supports them and an upper heated plate presses the film onto the tray flange. For MAP, the chamber is first evacuated and filled with a gas mix — typically carbon dioxide and nitrogen, sometimes oxygen for red meat — before sealing. For skin packs, the heated top film is drawn down onto the product by vacuum. A cutting knife trims the film to the tray shape, and sealed trays exit for labelling and inspection.

Sealing temperature, pressure and time are set per tray and film combination. Gas mixers and residual oxygen checks are part of a MAP system, since the gas mix only protects the product if the seal and the mix are both right.

Which configuration fits

Form	Suits	Watch out for
Semi-automatic	Small batches, testing new products	Output depends on operator
Continuous inline	Steady production with automated filling	Needs consistent tray supply and spacing
MAP	Ready meals, salads, fresh meat	Gas supply, mixer and residual oxygen checks
Vacuum skin	Meat and fish cuts, premium packs	Special films; slower cycles

What we need from you to quote

• Tray samples or drawings and lidding film specification
• Product, fill weight and whether sauce or fat may reach the flange
• MAP gas mixture or skin pack requirement
• Target output in sealed trays per minute
• Number of tray formats and changeover frequency
• Seal checks and labelling needs
• Power, compressed air, gas supply and room temperature

Where it sits in a line

Trays are typically filled by hand, by depositor or by a multihead weigher. Upstream, ready meals may come from a prepared meal production line and a food vacuum cooler. After sealing, trays pass an in-line checkweigher and a food metal detector before chilled storage.