Form-fill-seal (FFS) equipment is used across the packaging industry to form a package from film, fill it with product, and seal it for protection, transport, and display. Consistent heat sealing is one of the most important factors in overall package quality because poor seals can lead to product loss, wasted material, downtime, and reduced throughput. As packaging operations work with a wider range of films, including recyclable and other newer materials, precision temperature control and well‑engineered sealing systems have become increasingly important for achieving repeatable, high‑quality seals.
What is FFS Equipment?
Form-fill-seal equipment is automated packaging machinery that forms film into the required package shape, fills the package with product, and then seals it to preserve the contents. Two common machine orientations are vertical form-fill-seal (VFFS) and horizontal form-fill-seal (HFFS).
VFFS machines are typically well suited for flowable granular, loose, or liquid products and offer the benefit of a smaller footprint, although their taller design can create ceiling-space constraints and they may be more limited by gravity-fed product flow. HFFS machines generally require more floor space, but they can support more complex package shapes, often run at higher speeds, and are better suited for single-item packaging or less flowable products. For both machine types, seal quality remains a critical performance factor.
An example of a VFFS machine.Toss Machine Components
Critical heat-seal components of form-fill-seal machines
Used widely in food, medical, industrial, and consumer packaging, automated FFS machines rely on plastic films to create packages that protect, preserve, and present a wide range of products. These packages must be formed, filled, and sealed precisely, often at high speeds, while also standing up to transport, handling, and end-use requirements. Whether the application involves sterile medical products, electronics, or food packaging, seal quality has a direct impact on package performance.
To meet these requirements, the sealing system plays a crucial role. Precision temperature control systems provide the response and accuracy needed to seal a wide variety of polymeric films used in contemporary packaging while helping reduce scrap, downtime, and unnecessary operating costs.
New advances help solve common challenges faced by packaging engineers
Temperature control, material selection, and machine calibration all affect seal integrity. Material selection determines the required sealing parameters, including time, temperature, and pressure, and those parameters cannot be achieved consistently without proper calibration.
The two most common heat-sealing approaches used in FFS equipment are constant heat sealing and impulse heat sealing. Constant heat technologies, often called hot bar sealers, use heated tooling that is maintained at a constant temperature, also known as direct-contact thermal sealing. They use one or more heated bars, irons, or dies which contact the material to heat the interface and form a bond. They work best with films engineered for constant heat sealing.
These are typically films that do not require much of a cooling cycle, for example, laminated foil. For that reason, constant heat is generally not the best choice for many high-speed polyethylene film applications, as well as some newer biodegradable films entering the market which require significant cooling parameters.
TOSS forming shoulder for VFFS machines to transform a single layer of film into a tube which is then filled with product and sealed to form packaging.Toss Machine Components
In impulse heat sealing systems, one or more heating elements are placed between a resilient silicone rubber backing and a release layer. The heating elements are not continuously heated; instead, heat is generated only when a seal needs to be made. When film is conveyed into place, the sealing bars actuate and electric current is applied to the heating elements to quickly heat and achieve the temperature parameter. Impulse sealing reaches the required temperature much faster than constant‑heat sealing equipment while also cooling off much quicker. This enables speedy equipment start up times for manufacturing and typically expeditious equipment cool down times for maintenance when needed.
Several impulse heat-sealing approaches are available. Basic systems may provide limited or no temperature feedback, which can allow temperatures to drift and increase the risk of inconsistent seals or seal failure. Advances in heat-sealing technology have significantly changed the landscape of FFS packaging over the past decade.
Several engineered impulse heat‑sealing innovations provided by TOSS Machine Components, Inc. enable equipment to achieve faster seals while maintaining consistent results, forming an integrated, engineered sealing system rather than a collection of individual components. For example, TOSS PIREG® temperature controllers provide management of the sealing process with the instantaneous feedback required to maintain the desired sealing temperature within milliseconds and regulate the selected temperature and sealing time with repeated precision. The result is higher productivity, fewer rejects, superior seals, and reduced cost.
TOSS PIREG controllers help maintain highly consistent heat‑seal band temperature throughout the sealing cycle. Their fast response and precise control are ideal for sealing a wide variety of polymeric films. The PIREG controller measures the temperature 60 times a second, adjusting the power to the heat-seal band to ensure the band stays at the correct temperature throughout the sealing cycle as cold films absorb heat. The controller prevents temperature overshoot, can seal films requiring a cooling phase, and reduces the time required to reach sealing temperature. The controls also offer robust diagnostics and data logging capabilities to help users identify and troubleshoot issues more quickly.
TOSS Alloy-20 heat seal bands are available in a wide variety of configurations to achieve the desired result in your application.Toss Machine Components
Another advance is the TOSS Alloy-20® heat-seal band, which can be sourced in a wide variety of widths and profiles to produce the desired heat seal result. Examples include wide or narrow seals, intermittent seals, multi-line seals, as well as seal and cut bands which trim excess film while providing a hermetic seal in one process eliminating the need for a separate knife component. When paired with PIREG controllers and the TOSS system, ultra fast heat up times to 300°C can be achieved in 400 milliseconds (ms) enabling faster cycle times and consistent temperature through the seal cycle because energy can be replaced quicker than cold film can draw from the seal band.
Key considerations for seal quality and machine uptime
To achieve consistent results, engineers and operators should focus on a few core factors:
- Maintaining sealing jaws and heat‑seal bands properly and ensuring consistent, uniform pressure on the heat‑seal band
- Understanding the film being sealed and what is inside the package
- Determining whether seal‑and‑cut capability is needed
- Defining the required seal length and width before selecting a band design
How do process controls support seal quality?
With a clear understanding of material and equipment requirements, the next step is to focus on process parameters and control systems. To achieve consistently high‑quality seals, it is essential to maintain adequate dwell time and to select sealing technology that matches the specific film in use. In addition, controllers equipped with diagnostics and data logging can help operators identify and resolve issues faster, reducing downtime and supporting more efficient production.
Customer success story
To illustrate how engineered impulse sealing systems can improve results in demanding applications, consider the experience of a leading international VFFS machine manufacturer that needed to produce uniform, dependable seals, particularly when sealing directly above liquids. This process often increased susceptibility to contamination, leaks, and compromised seal integrity.
“As a manufacturer of VFFS machines for liquid packaging, achieving a consistent and reliable seal is a significant challenge, especially when sealing directly over liquid. TOSS technology has proven to be a key component in our solutions, allowing us to maintain perfect, repeatable seals even in demanding applications. Their quality and precision have helped us raise our sealing performance to the highest standards,” stated the customer.
By incorporating TOSS technology into their VFFS machinery, the manufacturer improved seal consistency, reduced product loss, and increased operational efficiency, helping it maintain high standards for packaging quality and reliability.
New trends shaping the future of heat sealing in flexible packaging
Achieving consistent seal quality in form-fill-seal operations is both a technical and operational imperative. As packaging materials diversify and sustainability demands grow, the integration of advanced technologies, such as precision temperature controllers and innovative heat-seal bands, has become essential for ensuring seal integrity, maximizing machine uptime, and reducing waste. By aligning material selection and process control, manufacturers can overcome the challenges of sealing a wide variety of polymeric films, including the latest recyclable substrates.
As the industry pushes for faster production, broader film compatibility, and more sustainable packaging materials, advanced temperature control and engineered heat‑seal systems will play an increasingly important role. For packaging engineers and OEMs alike, the ability to deliver repeatable, high-quality seals across changing materials will remain a key competitive advantage.
Brandon Hoser leads business development and marketing for TOSS Machine Components. Based out of Nazareth, Pennsylvania, Brandon specializes in educating clients on state-of-the-art, validatable impulse heat-sealing technology and equipment. Armed with an MBA and a strong background in industrial machine building, Brandon leverages his extensive experience in heavily regulated industries to guide partners toward optimal, high-performance outcomes in their heat-sealing applications.
