Permanent-seal lidding film for sealable PP trays

The permanent-seal lidding film for sealable PP trays is a transparent sealing film designed for a permanent seal. It can be chosen for tray packs where the film remains attached to the rim after sealing and the pack is opened by cutting. The clear appearance allows the food to be presented, while the tray and film form a single unit during handling. To make the right choice, we take the sealable surface of the polypropylene tray and the operation of the tray sealer together as the basis.

A permanent seal on the PP rim

The aim of the permanent seal is a film attached evenly along the tray rim. The sealing temperature, time and pressure must be matched to the chosen film, tray and machine. For a good result, the rim must be clean and in good condition, so food or liquid getting onto the sealing surface must be avoided during filling. A trial seal shows how even the adhesion is and helps check how the finished pack behaves under the planned handling conditions.

Food and liquids in trays

The film can be agreed for PP tray food packaging and, in a suitable combination, also for sealing hot food or soup. The filling temperature and later storage must be assessed together with the suitability of the tray, the film and the seal. With liquid fills, the right fill level is particularly important, because liquid on the rim can make sealing difficult. This version is not a gas barrier, so we recommend it for products that do not require modified atmosphere packaging; storage conditions must be matched to the specific food.

Machine use and contour cutting

The permanent-seal lidding film can be chosen for manual, semi-automatic or automatic tray sealing workflows, and it is suitable for contour cutting. We agree the reel width, winding and the details required for the machine based on the specific tray and tooling. The film must cover the sealing rim properly, and a neat pack edge is needed after cutting. During an introductory trial, checking film guidance, sealing and cutting together makes it possible to establish an even packaging process. With contour cutting, the film overhang is determined by the tooling and the tray rim together.

Transparent lidding with your own artwork

The film can also be made with your own print, so the top surface of the tray can carry branding and product information. The artwork should be positioned so that both the visibility of the food and the legibility of the text are ensured. The permanent seal must also be taken into account in the customer information: the opening method should be clear, especially for liquid products or products served hot. We match the markings to the actual tray size and the area defined by contour cutting.

When looking for permanent-seal lidding film for PP trays, please send us the tray details or a sample, the type of tray sealer and the characteristics of the packed food. Knowing the filling temperature and the desired print, we can refine the combination. At Kollár Pakk we start from the relationship between tray, film and machine, so that the permanent seal works well in day-to-day packing.