The concept of the development was to seal flexible packaging in a way which significantly reduces the amount of film required to make the seal and also to deliver improved seal integrity where needed for sensitive products.
Integrity Seal™ is a new generation impulse heating technology which uses a novel means of applying heat to the packaging film, combined with a unique non heated, cutter in the front jaw. The seal produced is only 1 mm wide compared with conventional crimp seals which are typically 15 mm wide.
Integrity Seal™ jaws are designed to be retro fitted to any type of existing bagging machine and typically takes half a day to fit.
With Integrity Seal™ only the rear jaw is heated. A very thin, narrow laminated impulse element heats when triggered by the jaw closing signal. The low mass design allows the element to heat very rapidly to the polymer melt temperature, typically 280 Deg C. Because the element is also very narrow only a small area of film is heated. The rear jaw also has a chamber behind the element filled with chilled water.
The function of the chilled water is to remove the heat from the element on each cycle so cooling the polymer. The seal is cooled in order to harden the polymer so it has sufficient strength to support the falling product.
The front jaw uses a unique design of anvil combining a hard resin, square profile, cutter and moulded side rubbers. A “V” shaped protrusion is produced by the way the cutter is mounted between the rubbers. This “V” protrusion acts as the cutting blade to press the polymer against the heated rear jaw so that the high temperature produces a weld seal. The heat transmission is partially through the cut edge of the film so the resulting seal is made from the full thickness of the polymer, typically 70 micron. A further design feature of the side rubbers is the inclusion of embossed shoulders either side of the “V” which help clamp the polymer during the heating process and produce a neat embossed seal area just 1 mm wide.
The resin cutter and side rubbers are simply pressed into the housing so allowing rapid and easy change, without tools, when they become worn. The cutter can be turned so that all 4 edges may be used.