What Are Heat Sealable Films? Applications And Uses

Heat Sealable Films are Multi – layered films that comprises of an outer coating which prevents it from melting the core of the film and damaging it. The core is often polypropylene and there is a sealant layer inside of the film that has a lower melting point and it works in order to keep the seal intact and pack the product tightly.

For packaging that requires a high level of security or confidentiality, a high-intensity seal is often used to reinforce the bond and keep the packaging securely closed. In such cases, heat seal films are the ideal choice. Additionally, heat seal films are more cost-effective compared to cold seal films. To provide optimal protection for various products, heat seal films are available in a wide range of laminations tailored to meet specific packaging needs.

What Are Heat Sealable Films?

Heat sealable films are specialized, multi-layered shrink films designed for packaging products that require higher heat levels than standard flexible films.

These films feature an outer coating that protects the core from melting during the heating process, preventing damage to the film. Typically, the core is made of either polypropylene or polyethylene.

Inside the film, there is a sealant layer with a lower melting point than the rest of the material. This allows the seal to remain intact, ensuring a tightly sealed final product.

For packaging confidential or sensitive items, an ultra-intense heat seal is used to securely bond the film, preventing any visibility of the contents. This type of seal is superior to those found in traditional shrink films.

Heat sealable films are custom-made to suit the specific needs of each product, with various laminations available to meet the required heating conditions.

When producing a seal with heat sealable films, three key factors must be carefully considered:

1. Heat Application: Heat is essential for heat sealable films but is not required for cold seal films. It's crucial to maintain the proper temperature on the sealing surfaces to ensure a secure bond.

2. Sealing Time: The amount of time the machine jaws need to keep the sealing material in place is also an important factor in the sealing process.

3. Pressure: The pressure applied to the sealing material plays a critical role in ensuring a tight seal.

Any changes made to one of these factors will likely require adjustments to the other two. For example, if the machine speed is increased significantly, the time the sealing material is held in the machine jaws will decrease, which may necessitate an increase in temperature to compensate for the reduced sealing time.

What Applications Are Heat Sealable Films Used For?

Heat sealable films have a wide range of applications across various industries. Common uses include:

1. Snack Food Packaging – These films are commonly used in flexible packaging, including transparent heat sealable windows and bags for dried fruits, granola bars, and other snack items.

2. Ovenable Films and Bagging for Roasting and Cooking – Used in applications like pre-made frozen meals, these films can be placed directly in the oven or microwave for convenient cooking and meal prep.

3. Lidding – Lidding films serve as an extra layer of protection between the product and the cap of plastic food containers. They are typically used for packaging food items like soups, meats (beef, poultry, pork), and dairy products such as yogurt and cottage cheese.

4. Tubing – Heat-sealable tubing is a flat plastic material rolled onto a reel. It is often cut into shrink sleeves, which are then used to package products such as plastic or glass bottles, flag poles, fishing rods, and other similar consumer goods.

5. Protection and Reinforcement for Glass Surfaces – Heat sealable films can also be used to laminate glass, providing extra reinforcement and protection for the glass surface.

Who Uses Heat Sealable Films?

Heat-sealable films are primarily used by the same types of companies that utilize shrink films for packaging. However, when an application requires higher heat resistance—such as for ovenable films—heat sealable films are chosen over traditional shrink films to meet the specific needs of the product.