Tray Sealers fall into four main categories. There are three that use a preformed tray and can either just seal a film into the tray or can add a modified atmosphere into the tray.
The fourth category of tray sealer uses thermoforming, a process that enables plastic to be formed into specific shapes. The process involves using sheets or films of plastic which are heated and then moulded to the desired shape.
A thermoforming machine uses a roll of film to produce a packaging tray which is then loaded and sealed before the machine separates the finished sealed trays. The film is fed into the machine where it is heated to the necessary temperature before a mold is used to shape the plastic into the required shape, using a vacuum and pressurised air to apply the required details to the tray.
Thermoforming machines are widely used to produce a packaging for a range of food items including ready meals, packaged fresh produce, dairy products and baked goods.