A good sealing machine can still produce a bad seal if the film is wrong. The film is the part that actually bonds to your container, so choosing it carefully saves you from leaks, wrinkles and wasted packs. Here is what to check.
What sealing film does
Sealing film is a thin plastic layer that covers the top of a tray, cup or bowl. One side of the film has a heat-seal layer. When the machine presses the film onto the rim with heat, that layer melts slightly and bonds to the container. When it cools, you have a sealed pack.
The film must match the container material
This is the most important rule. The heat-seal layer of the film has to be able to bond with the material of your tray or cup. Common container materials in food packing include:
- PP (polypropylene) for many microwave-safe trays, bowls and cups
- PET and CPET for clear containers and some ovenable trays
- PS (polystyrene) for many cups and light containers
- Coated paper or foil for some meal trays
A film that works well on one of these may not seal on another. When you ask a supplier for film, give them the container material and, if possible, a sample container.
Other things to ask about
- Strength of the seal. Some films open easily by hand, while others make a stronger seal that resists leaks better. Choose the one that suits your food and your customers.
- Printing. Plain film is common, and printed film can carry your brand name or logo. Ask your film supplier what is possible and what the minimum order is.
- Reheating. If customers will microwave the meal, make sure both container and film are suitable for it.
- Thickness and clarity. Clear film lets the customer see the food, and thicker film is more durable.
Test before you buy in bulk
- Order a small quantity of film.
- Seal a few containers with your usual food and some with water.
- Gently turn a sealed pack on its side and check for leaks.
- Open a few by hand and see how the seal peels.
- Keep one sealed pack for a few hours to see how it holds in a delivery bag.
If the film wrinkles or does not stick, the problem could be the film, the container or the machine settings. Our guide to sealing problems and fixes helps you find out which.
Store film properly
Keep film rolls or sheets in a dry, cool place, away from dust and direct sun. Close the pack after use. Damp or dusty film does not seal well.
We can guide you
We supply the sealing machines and can advise which film suits your container. Send us a photo of your tray or cup and tell us what material it is made of. Message us on WhatsApp at +91 85108 13358 or use the enquiry form. You can also read the FAQ for more answers.
