When it comes to heat sealing, there are essentially three main processes to consider: Impulse Heat, Constant Heat, and Vacuum Sealing. Choosing the right technology depends on the material, bag thickness, production volume, and product requirements.
Impulse Heat Sealers are ideal for sealing like-for-like thermoplastic films such as polyethylene (PE) and polypropylene (PP). The element heats only during the sealing process and cools immediately afterward, making them energy-efficient and safe to operate.
Impulse sealers are perfect for low to medium-volume production. Standard models can handle films up to 1000 gauge (250 micron), while double-element models or wider seal jaws are available for thicker or gusseted films. Materials like nylon laminates, polyurethane, and some PVCs are sealable, but testing is recommended. Hulme Martin offers a testing service to ensure the correct machine for your product.
All Hulme Martin impulse sealers are fitted with precise electronic timers. Our Duo models feature advanced timers that indicate both welding and cooling periods, ensuring consistent seal quality. Optional features include cutters for trimming surplus material or converting lay-flat tubing into bags.
Constant Heat Sealers maintain a stable temperature across the sealing bar, making them ideal for laminated materials or films with multiple layers having different melting points, such as foils, coated papers, and polypropylene laminates. The seal is typically 14mm wide and crimped for extra strength, preventing delamination.
Constant heat machines are suitable for medium to high-volume production where thicker or multi-layer films are used. Unlike impulse sealers, they require warm-up and use more energy, so safety precautions are important as the sealing jaws remain hot even when idle.
Vacuum Sealers remove air from the package before sealing, extending shelf life and protecting sensitive products. Chamber vacuum sealers are ideal for smaller packs and liquids, offering simple operation and consistent results. Probe vacuum sealers can handle larger sacks or bulk products, with optional support trays or holders to create compact “brick-shaped” packs.
Vacuum and vacuum-gas sealers are especially useful for food, electronics, and high-value products that require extended freshness or protection from oxygen.
Consider these factors when selecting a heat sealer:
To ensure long-lasting performance, replace worn PTFE covers, keep sealing bars clean, and regularly check electronic timers or temperature controllers. Consistent maintenance guarantees reliable seal quality and reduces downtime.
Hulme Martin sealer models are designed with practicality and reliability in mind, helping you achieve professional, consistent seals every time.